This is v6 of the slab cgroup controller rework.
The patchset moves the accounting from the page level to the object
level. It allows to share slab pages between memory cgroups.
This leads to a significant win in the slab utilization (up to 45%)
and the corresponding drop in the total kernel memory footprint.
The reduced number of unmovable slab pages should also have a positive
effect on the memory fragmentation.
The patchset makes the slab accounting code simpler: there is no more
need in the complicated dynamic creation and destruction of per-cgroup
slab caches, all memory cgroups use a global set of shared slab caches.
The lifetime of slab caches is not more connected to the lifetime
of memory cgroups.
The more precise accounting does require more CPU, however in practice
the difference seems to be negligible. We've been using the new slab
controller in Facebook production for several months with different
workloads and haven't seen any noticeable regressions. What we've seen
were memory savings in order of 1 GB per host (it varied heavily depending
on the actual workload, size of RAM, number of CPUs, memory pressure, etc).
The third version of the patchset added yet another step towards
the simplification of the code: sharing of slab caches between
accounted and non-accounted allocations. It comes with significant
upsides (most noticeable, a complete elimination of dynamic slab caches
creation) but not without some regression risks, so this change sits
on top of the patchset and is not completely merged in. So in the unlikely
event of a noticeable performance regression it can be reverted separately.
v6:
1) rebased on top of the mm tree
2) removed a redundant check from cache_from_obj(), suggested by Vlastimil
v5:
1) fixed a build error, spotted by Vlastimil
2) added a comment about memcg->nr_charged_bytes, asked by Johannes
3) added missed acks and reviews
v4:
1) rebased on top of the mm tree, some fixes here and there
2) merged obj_to_index() with slab_index(), suggested by Vlastimil
3) changed objects_per_slab() to a better objects_per_slab_page(),
suggested by Vlastimil
4) other minor fixes and changes
v3:
1) added a patch that switches to a global single set of kmem_caches
2) kmem API clean up dropped, because if has been already merged
3) byte-sized slab vmstat API over page-sized global counters and
bytes-sized memcg/lruvec counters
3) obj_cgroup refcounting simplifications and other minor fixes
4) other minor changes
v2:
1) implemented re-layering and renaming suggested by Johannes,
added his patch to the set. Thanks!
2) fixed the issue discovered by Bharata B Rao. Thanks!
3) added kmem API clean up part
4) added slab/memcg follow-up clean up part
5) fixed a couple of issues discovered by internal testing on FB fleet.
6) added kselftests
7) included metadata into the charge calculation
8) refreshed commit logs, regrouped patches, rebased onto mm tree, etc
v1:
1) fixed a bug in zoneinfo_show_print()
2) added some comments to the subpage charging API, a minor fix
3) separated memory.kmem.slabinfo deprecation into a separate patch,
provided a drgn-based replacement
4) rebased on top of the current mm tree
RFC:
https://lwn.net/Articles/798605/
Johannes Weiner (1):
mm: memcontrol: decouple reference counting from page accounting
Roman Gushchin (18):
mm: memcg: factor out memcg- and lruvec-level changes out of
__mod_lruvec_state()
mm: memcg: prepare for byte-sized vmstat items
mm: memcg: convert vmstat slab counters to bytes
mm: slub: implement SLUB version of obj_to_index()
mm: memcg/slab: obj_cgroup API
mm: memcg/slab: allocate obj_cgroups for non-root slab pages
mm: memcg/slab: save obj_cgroup for non-root slab objects
mm: memcg/slab: charge individual slab objects instead of pages
mm: memcg/slab: deprecate memory.kmem.slabinfo
mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h
mm: memcg/slab: use a single set of kmem_caches for all accounted
allocations
mm: memcg/slab: simplify memcg cache creation
mm: memcg/slab: remove memcg_kmem_get_cache()
mm: memcg/slab: deprecate slab_root_caches
mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo()
mm: memcg/slab: use a single set of kmem_caches for all allocations
kselftests: cgroup: add kernel memory accounting tests
tools/cgroup: add memcg_slabinfo.py tool
drivers/base/node.c | 6 +-
fs/proc/meminfo.c | 4 +-
include/linux/memcontrol.h | 85 ++-
include/linux/mm_types.h | 5 +-
include/linux/mmzone.h | 24 +-
include/linux/slab.h | 5 -
include/linux/slab_def.h | 9 +-
include/linux/slub_def.h | 31 +-
include/linux/vmstat.h | 14 +-
kernel/power/snapshot.c | 2 +-
mm/memcontrol.c | 608 +++++++++++--------
mm/oom_kill.c | 2 +-
mm/page_alloc.c | 8 +-
mm/slab.c | 70 +--
mm/slab.h | 372 +++++-------
mm/slab_common.c | 643 +--------------------
mm/slob.c | 12 +-
mm/slub.c | 229 +-------
mm/vmscan.c | 3 +-
mm/vmstat.c | 30 +-
mm/workingset.c | 6 +-
tools/cgroup/memcg_slabinfo.py | 226 ++++++++
tools/testing/selftests/cgroup/.gitignore | 1 +
tools/testing/selftests/cgroup/Makefile | 2 +
tools/testing/selftests/cgroup/test_kmem.c | 382 ++++++++++++
25 files changed, 1374 insertions(+), 1405 deletions(-)
create mode 100755 tools/cgroup/memcg_slabinfo.py
create mode 100644 tools/testing/selftests/cgroup/test_kmem.c
--
2.25.4
This is fairly big but mostly red patch, which makes all accounted
slab allocations use a single set of kmem_caches instead of
creating a separate set for each memory cgroup.
Because the number of non-root kmem_caches is now capped by the number
of root kmem_caches, there is no need to shrink or destroy them
prematurely. They can be perfectly destroyed together with their
root counterparts. This allows to dramatically simplify the
management of non-root kmem_caches and delete a ton of code.
This patch performs the following changes:
1) introduces memcg_params.memcg_cache pointer to represent the
kmem_cache which will be used for all non-root allocations
2) reuses the existing memcg kmem_cache creation mechanism
to create memcg kmem_cache on the first allocation attempt
3) memcg kmem_caches are named <kmemcache_name>-memcg,
e.g. dentry-memcg
4) simplifies memcg_kmem_get_cache() to just return memcg kmem_cache
or schedule it's creation and return the root cache
5) removes almost all non-root kmem_cache management code
(separate refcounter, reparenting, shrinking, etc)
6) makes slab debugfs to display root_mem_cgroup css id and never
show :dead and :deact flags in the memcg_slabinfo attribute.
Following patches in the series will simplify the kmem_cache creation.
Signed-off-by: Roman Gushchin <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
---
include/linux/memcontrol.h | 5 +-
include/linux/slab.h | 5 +-
mm/memcontrol.c | 163 +++-----------
mm/slab.c | 16 +-
mm/slab.h | 145 ++++---------
mm/slab_common.c | 426 ++++---------------------------------
mm/slub.c | 38 +---
7 files changed, 128 insertions(+), 670 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index ba7065c0922a..e2c4d54aa1f6 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -317,7 +317,6 @@ struct mem_cgroup {
/* Index in the kmem_cache->memcg_params.memcg_caches array */
int kmemcg_id;
enum memcg_kmem_state kmem_state;
- struct list_head kmem_caches;
struct obj_cgroup __rcu *objcg;
struct list_head objcg_list;
#endif
@@ -1404,9 +1403,7 @@ static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
}
#endif
-struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep,
- struct obj_cgroup **objcgp);
-void memcg_kmem_put_cache(struct kmem_cache *cachep);
+struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
#ifdef CONFIG_MEMCG_KMEM
int __memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp,
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 6d454886bcaf..310768bfa8d2 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -155,8 +155,7 @@ struct kmem_cache *kmem_cache_create_usercopy(const char *name,
void kmem_cache_destroy(struct kmem_cache *);
int kmem_cache_shrink(struct kmem_cache *);
-void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
-void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *);
+void memcg_create_kmem_cache(struct kmem_cache *cachep);
/*
* Please use this macro to create slab caches. Simply specify the
@@ -578,8 +577,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
return __kmalloc_node(size, flags, node);
}
-int memcg_update_all_caches(int num_memcgs);
-
/**
* kmalloc_array - allocate memory for an array.
* @n: number of elements.
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 51e85d05095c..995204f65217 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -350,7 +350,7 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg,
}
/*
- * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
+ * This will be used as a shrinker list's index.
* The main reason for not using cgroup id for this:
* this works better in sparse environments, where we have a lot of memcgs,
* but only a few kmem-limited. Or also, if we have, for instance, 200
@@ -569,20 +569,16 @@ ino_t page_cgroup_ino(struct page *page)
unsigned long ino = 0;
rcu_read_lock();
- if (PageSlab(page) && !PageTail(page)) {
- memcg = memcg_from_slab_page(page);
- } else {
- memcg = page->mem_cgroup;
+ memcg = page->mem_cgroup;
- /*
- * The lowest bit set means that memcg isn't a valid
- * memcg pointer, but a obj_cgroups pointer.
- * In this case the page is shared and doesn't belong
- * to any specific memory cgroup.
- */
- if ((unsigned long) memcg & 0x1UL)
- memcg = NULL;
- }
+ /*
+ * The lowest bit set means that memcg isn't a valid
+ * memcg pointer, but a obj_cgroups pointer.
+ * In this case the page is shared and doesn't belong
+ * to any specific memory cgroup.
+ */
+ if ((unsigned long) memcg & 0x1UL)
+ memcg = NULL;
while (memcg && !(memcg->css.flags & CSS_ONLINE))
memcg = parent_mem_cgroup(memcg);
@@ -2822,12 +2818,18 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p)
page = virt_to_head_page(p);
/*
- * Slab pages don't have page->mem_cgroup set because corresponding
- * kmem caches can be reparented during the lifetime. That's why
- * memcg_from_slab_page() should be used instead.
+ * Slab objects are accounted individually, not per-page.
+ * Memcg membership data for each individual object is saved in
+ * the page->obj_cgroups.
*/
- if (PageSlab(page))
- return memcg_from_slab_page(page);
+ if (page_has_obj_cgroups(page)) {
+ struct obj_cgroup *objcg;
+ unsigned int off;
+
+ off = obj_to_index(page->slab_cache, page, p);
+ objcg = page_obj_cgroups(page)[off];
+ return obj_cgroup_memcg(objcg);
+ }
/* All other pages use page->mem_cgroup */
return page->mem_cgroup;
@@ -2882,9 +2884,7 @@ static int memcg_alloc_cache_id(void)
else if (size > MEMCG_CACHES_MAX_SIZE)
size = MEMCG_CACHES_MAX_SIZE;
- err = memcg_update_all_caches(size);
- if (!err)
- err = memcg_update_all_list_lrus(size);
+ err = memcg_update_all_list_lrus(size);
if (!err)
memcg_nr_cache_ids = size;
@@ -2903,7 +2903,6 @@ static void memcg_free_cache_id(int id)
}
struct memcg_kmem_cache_create_work {
- struct mem_cgroup *memcg;
struct kmem_cache *cachep;
struct work_struct work;
};
@@ -2912,31 +2911,24 @@ static void memcg_kmem_cache_create_func(struct work_struct *w)
{
struct memcg_kmem_cache_create_work *cw =
container_of(w, struct memcg_kmem_cache_create_work, work);
- struct mem_cgroup *memcg = cw->memcg;
struct kmem_cache *cachep = cw->cachep;
- memcg_create_kmem_cache(memcg, cachep);
+ memcg_create_kmem_cache(cachep);
- css_put(&memcg->css);
kfree(cw);
}
/*
* Enqueue the creation of a per-memcg kmem_cache.
*/
-static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
- struct kmem_cache *cachep)
+static void memcg_schedule_kmem_cache_create(struct kmem_cache *cachep)
{
struct memcg_kmem_cache_create_work *cw;
- if (!css_tryget_online(&memcg->css))
- return;
-
cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN);
if (!cw)
return;
- cw->memcg = memcg;
cw->cachep = cachep;
INIT_WORK(&cw->work, memcg_kmem_cache_create_func);
@@ -2944,102 +2936,26 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
}
/**
- * memcg_kmem_get_cache: select the correct per-memcg cache for allocation
+ * memcg_kmem_get_cache: select memcg or root cache for allocation
* @cachep: the original global kmem cache
*
* Return the kmem_cache we're supposed to use for a slab allocation.
- * We try to use the current memcg's version of the cache.
*
* If the cache does not exist yet, if we are the first user of it, we
* create it asynchronously in a workqueue and let the current allocation
* go through with the original cache.
- *
- * This function takes a reference to the cache it returns to assure it
- * won't get destroyed while we are working with it. Once the caller is
- * done with it, memcg_kmem_put_cache() must be called to release the
- * reference.
*/
-struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep,
- struct obj_cgroup **objcgp)
+struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep)
{
- struct mem_cgroup *memcg;
struct kmem_cache *memcg_cachep;
- struct memcg_cache_array *arr;
- int kmemcg_id;
- VM_BUG_ON(!is_root_cache(cachep));
-
- if (memcg_kmem_bypass())
+ memcg_cachep = READ_ONCE(cachep->memcg_params.memcg_cache);
+ if (unlikely(!memcg_cachep)) {
+ memcg_schedule_kmem_cache_create(cachep);
return cachep;
-
- rcu_read_lock();
-
- if (unlikely(current->active_memcg))
- memcg = current->active_memcg;
- else
- memcg = mem_cgroup_from_task(current);
-
- if (!memcg || memcg == root_mem_cgroup)
- goto out_unlock;
-
- kmemcg_id = READ_ONCE(memcg->kmemcg_id);
- if (kmemcg_id < 0)
- goto out_unlock;
-
- arr = rcu_dereference(cachep->memcg_params.memcg_caches);
-
- /*
- * Make sure we will access the up-to-date value. The code updating
- * memcg_caches issues a write barrier to match the data dependency
- * barrier inside READ_ONCE() (see memcg_create_kmem_cache()).
- */
- memcg_cachep = READ_ONCE(arr->entries[kmemcg_id]);
-
- /*
- * If we are in a safe context (can wait, and not in interrupt
- * context), we could be be predictable and return right away.
- * This would guarantee that the allocation being performed
- * already belongs in the new cache.
- *
- * However, there are some clashes that can arrive from locking.
- * For instance, because we acquire the slab_mutex while doing
- * memcg_create_kmem_cache, this means no further allocation
- * could happen with the slab_mutex held. So it's better to
- * defer everything.
- *
- * If the memcg is dying or memcg_cache is about to be released,
- * don't bother creating new kmem_caches. Because memcg_cachep
- * is ZEROed as the fist step of kmem offlining, we don't need
- * percpu_ref_tryget_live() here. css_tryget_online() check in
- * memcg_schedule_kmem_cache_create() will prevent us from
- * creation of a new kmem_cache.
- */
- if (unlikely(!memcg_cachep))
- memcg_schedule_kmem_cache_create(memcg, cachep);
- else if (percpu_ref_tryget(&memcg_cachep->memcg_params.refcnt)) {
- struct obj_cgroup *objcg = rcu_dereference(memcg->objcg);
-
- if (!objcg || !obj_cgroup_tryget(objcg)) {
- percpu_ref_put(&memcg_cachep->memcg_params.refcnt);
- goto out_unlock;
- }
-
- *objcgp = objcg;
- cachep = memcg_cachep;
}
-out_unlock:
- rcu_read_unlock();
- return cachep;
-}
-/**
- * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache
- * @cachep: the cache returned by memcg_kmem_get_cache
- */
-void memcg_kmem_put_cache(struct kmem_cache *cachep)
-{
- if (!is_root_cache(cachep))
- percpu_ref_put(&cachep->memcg_params.refcnt);
+ return memcg_cachep;
}
/**
@@ -3728,7 +3644,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
*/
memcg->kmemcg_id = memcg_id;
memcg->kmem_state = KMEM_ONLINE;
- INIT_LIST_HEAD(&memcg->kmem_caches);
return 0;
}
@@ -3741,22 +3656,13 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
if (memcg->kmem_state != KMEM_ONLINE)
return;
- /*
- * Clear the online state before clearing memcg_caches array
- * entries. The slab_mutex in memcg_deactivate_kmem_caches()
- * guarantees that no cache will be created for this cgroup
- * after we are done (see memcg_create_kmem_cache()).
- */
+
memcg->kmem_state = KMEM_ALLOCATED;
parent = parent_mem_cgroup(memcg);
if (!parent)
parent = root_mem_cgroup;
- /*
- * Deactivate and reparent kmem_caches and objcgs.
- */
- memcg_deactivate_kmem_caches(memcg, parent);
memcg_reparent_objcgs(memcg, parent);
kmemcg_id = memcg->kmemcg_id;
@@ -3791,10 +3697,8 @@ static void memcg_free_kmem(struct mem_cgroup *memcg)
if (unlikely(memcg->kmem_state == KMEM_ONLINE))
memcg_offline_kmem(memcg);
- if (memcg->kmem_state == KMEM_ALLOCATED) {
- WARN_ON(!list_empty(&memcg->kmem_caches));
+ if (memcg->kmem_state == KMEM_ALLOCATED)
static_branch_dec(&memcg_kmem_enabled_key);
- }
}
#else
static int memcg_online_kmem(struct mem_cgroup *memcg)
@@ -5386,9 +5290,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
/* The following stuff does not apply to the root */
if (!parent) {
-#ifdef CONFIG_MEMCG_KMEM
- INIT_LIST_HEAD(&memcg->kmem_caches);
-#endif
root_mem_cgroup = memcg;
return &memcg->css;
}
diff --git a/mm/slab.c b/mm/slab.c
index 02b4363930c1..7e8d0f62f30b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1239,7 +1239,7 @@ void __init kmem_cache_init(void)
nr_node_ids * sizeof(struct kmem_cache_node *),
SLAB_HWCACHE_ALIGN, 0, 0);
list_add(&kmem_cache->list, &slab_caches);
- memcg_link_cache(kmem_cache, NULL);
+ memcg_link_cache(kmem_cache);
slab_state = PARTIAL;
/*
@@ -2243,17 +2243,6 @@ int __kmem_cache_shrink(struct kmem_cache *cachep)
return (ret ? 1 : 0);
}
-#ifdef CONFIG_MEMCG
-void __kmemcg_cache_deactivate(struct kmem_cache *cachep)
-{
- __kmem_cache_shrink(cachep);
-}
-
-void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
-{
-}
-#endif
-
int __kmem_cache_shutdown(struct kmem_cache *cachep)
{
return __kmem_cache_shrink(cachep);
@@ -3861,7 +3850,8 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
return ret;
lockdep_assert_held(&slab_mutex);
- for_each_memcg_cache(c, cachep) {
+ c = memcg_cache(cachep);
+ if (c) {
/* return value determined by the root cache only */
__do_tune_cpucache(c, limit, batchcount, shared, gfp);
}
diff --git a/mm/slab.h b/mm/slab.h
index f219a29052d9..8f8552df5675 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -32,66 +32,25 @@ struct kmem_cache {
#else /* !CONFIG_SLOB */
-struct memcg_cache_array {
- struct rcu_head rcu;
- struct kmem_cache *entries[];
-};
-
/*
* This is the main placeholder for memcg-related information in kmem caches.
- * Both the root cache and the child caches will have it. For the root cache,
- * this will hold a dynamically allocated array large enough to hold
- * information about the currently limited memcgs in the system. To allow the
- * array to be accessed without taking any locks, on relocation we free the old
- * version only after a grace period.
- *
- * Root and child caches hold different metadata.
+ * Both the root cache and the child cache will have it. Some fields are used
+ * in both cases, other are specific to root caches.
*
* @root_cache: Common to root and child caches. NULL for root, pointer to
* the root cache for children.
*
* The following fields are specific to root caches.
*
- * @memcg_caches: kmemcg ID indexed table of child caches. This table is
- * used to index child cachces during allocation and cleared
- * early during shutdown.
- *
- * @root_caches_node: List node for slab_root_caches list.
- *
- * @children: List of all child caches. While the child caches are also
- * reachable through @memcg_caches, a child cache remains on
- * this list until it is actually destroyed.
- *
- * The following fields are specific to child caches.
- *
- * @memcg: Pointer to the memcg this cache belongs to.
- *
- * @children_node: List node for @root_cache->children list.
- *
- * @kmem_caches_node: List node for @memcg->kmem_caches list.
+ * @memcg_cache: pointer to memcg kmem cache, used by all non-root memory
+ * cgroups.
+ * @root_caches_node: list node for slab_root_caches list.
*/
struct memcg_cache_params {
struct kmem_cache *root_cache;
- union {
- struct {
- struct memcg_cache_array __rcu *memcg_caches;
- struct list_head __root_caches_node;
- struct list_head children;
- bool dying;
- };
- struct {
- struct mem_cgroup *memcg;
- struct list_head children_node;
- struct list_head kmem_caches_node;
- struct percpu_ref refcnt;
-
- void (*work_fn)(struct kmem_cache *);
- union {
- struct rcu_head rcu_head;
- struct work_struct work;
- };
- };
- };
+
+ struct kmem_cache *memcg_cache;
+ struct list_head __root_caches_node;
};
#endif /* CONFIG_SLOB */
@@ -234,8 +193,6 @@ bool __kmem_cache_empty(struct kmem_cache *);
int __kmem_cache_shutdown(struct kmem_cache *);
void __kmem_cache_release(struct kmem_cache *);
int __kmem_cache_shrink(struct kmem_cache *);
-void __kmemcg_cache_deactivate(struct kmem_cache *s);
-void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s);
void slab_kmem_cache_release(struct kmem_cache *);
void kmem_cache_shrink_all(struct kmem_cache *s);
@@ -281,14 +238,6 @@ static inline int cache_vmstat_idx(struct kmem_cache *s)
extern struct list_head slab_root_caches;
#define root_caches_node memcg_params.__root_caches_node
-/*
- * Iterate over all memcg caches of the given root cache. The caller must hold
- * slab_mutex.
- */
-#define for_each_memcg_cache(iter, root) \
- list_for_each_entry(iter, &(root)->memcg_params.children, \
- memcg_params.children_node)
-
static inline bool is_root_cache(struct kmem_cache *s)
{
return !s->memcg_params.root_cache;
@@ -319,6 +268,13 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
return s->memcg_params.root_cache;
}
+static inline struct kmem_cache *memcg_cache(struct kmem_cache *s)
+{
+ if (is_root_cache(s))
+ return s->memcg_params.memcg_cache;
+ return NULL;
+}
+
static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
{
/*
@@ -331,25 +287,9 @@ static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
((unsigned long)page->obj_cgroups & ~0x1UL);
}
-/*
- * Expects a pointer to a slab page. Please note, that PageSlab() check
- * isn't sufficient, as it returns true also for tail compound slab pages,
- * which do not have slab_cache pointer set.
- * So this function assumes that the page can pass PageSlab() && !PageTail()
- * check.
- *
- * The kmem_cache can be reparented asynchronously. The caller must ensure
- * the memcg lifetime, e.g. by taking rcu_read_lock() or cgroup_mutex.
- */
-static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
+static inline bool page_has_obj_cgroups(struct page *page)
{
- struct kmem_cache *s;
-
- s = READ_ONCE(page->slab_cache);
- if (s && !is_root_cache(s))
- return READ_ONCE(s->memcg_params.memcg);
-
- return NULL;
+ return ((unsigned long)page->obj_cgroups & 0x1UL);
}
static inline int memcg_alloc_page_obj_cgroups(struct page *page,
@@ -386,16 +326,25 @@ static inline struct kmem_cache *memcg_slab_pre_alloc_hook(struct kmem_cache *s,
size_t objects, gfp_t flags)
{
struct kmem_cache *cachep;
+ struct obj_cgroup *objcg;
+
+ if (memcg_kmem_bypass())
+ return s;
- cachep = memcg_kmem_get_cache(s, objcgp);
+ cachep = memcg_kmem_get_cache(s);
if (is_root_cache(cachep))
return s;
- if (obj_cgroup_charge(*objcgp, flags, objects * obj_full_size(s))) {
- memcg_kmem_put_cache(cachep);
+ objcg = get_obj_cgroup_from_current();
+ if (!objcg)
+ return s;
+
+ if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) {
+ obj_cgroup_put(objcg);
cachep = NULL;
}
+ *objcgp = objcg;
return cachep;
}
@@ -434,7 +383,6 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
}
}
obj_cgroup_put(objcg);
- memcg_kmem_put_cache(s);
}
static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page,
@@ -458,7 +406,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page,
}
extern void slab_init_memcg_params(struct kmem_cache *);
-extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
+extern void memcg_link_cache(struct kmem_cache *s);
#else /* CONFIG_MEMCG_KMEM */
@@ -466,9 +414,6 @@ extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
#define slab_root_caches slab_caches
#define root_caches_node list
-#define for_each_memcg_cache(iter, root) \
- for ((void)(iter), (void)(root); 0; )
-
static inline bool is_root_cache(struct kmem_cache *s)
{
return true;
@@ -490,7 +435,17 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
return s;
}
-static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
+static inline struct kmem_cache *memcg_cache(struct kmem_cache *s)
+{
+ return NULL;
+}
+
+static inline bool page_has_obj_cgroups(struct page *page)
+{
+ return false;
+}
+
+static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
{
return NULL;
}
@@ -527,8 +482,7 @@ static inline void slab_init_memcg_params(struct kmem_cache *s)
{
}
-static inline void memcg_link_cache(struct kmem_cache *s,
- struct mem_cgroup *memcg)
+static inline void memcg_link_cache(struct kmem_cache *s)
{
}
@@ -549,17 +503,14 @@ static __always_inline int charge_slab_page(struct page *page,
gfp_t gfp, int order,
struct kmem_cache *s)
{
-#ifdef CONFIG_MEMCG_KMEM
if (memcg_kmem_enabled() && !is_root_cache(s)) {
int ret;
ret = memcg_alloc_page_obj_cgroups(page, s, gfp);
if (ret)
return ret;
-
- percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
}
-#endif
+
mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
PAGE_SIZE << order);
return 0;
@@ -568,12 +519,9 @@ static __always_inline int charge_slab_page(struct page *page,
static __always_inline void uncharge_slab_page(struct page *page, int order,
struct kmem_cache *s)
{
-#ifdef CONFIG_MEMCG_KMEM
- if (memcg_kmem_enabled() && !is_root_cache(s)) {
+ if (memcg_kmem_enabled() && !is_root_cache(s))
memcg_free_page_obj_cgroups(page);
- percpu_ref_put_many(&s->memcg_params.refcnt, 1 << order);
- }
-#endif
+
mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
-(PAGE_SIZE << order));
}
@@ -722,9 +670,6 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
void *slab_start(struct seq_file *m, loff_t *pos);
void *slab_next(struct seq_file *m, void *p, loff_t *pos);
void slab_stop(struct seq_file *m, void *p);
-void *memcg_slab_start(struct seq_file *m, loff_t *pos);
-void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
-void memcg_slab_stop(struct seq_file *m, void *p);
int memcg_slab_show(struct seq_file *m, void *p);
#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 3c89c2adc930..e9deaafddbb6 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -131,141 +131,36 @@ int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
#ifdef CONFIG_MEMCG_KMEM
LIST_HEAD(slab_root_caches);
-static DEFINE_SPINLOCK(memcg_kmem_wq_lock);
-
-static void kmemcg_cache_shutdown(struct percpu_ref *percpu_ref);
void slab_init_memcg_params(struct kmem_cache *s)
{
s->memcg_params.root_cache = NULL;
- RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
- INIT_LIST_HEAD(&s->memcg_params.children);
- s->memcg_params.dying = false;
+ s->memcg_params.memcg_cache = NULL;
}
-static int init_memcg_params(struct kmem_cache *s,
- struct kmem_cache *root_cache)
+static void init_memcg_params(struct kmem_cache *s,
+ struct kmem_cache *root_cache)
{
- struct memcg_cache_array *arr;
-
- if (root_cache) {
- int ret = percpu_ref_init(&s->memcg_params.refcnt,
- kmemcg_cache_shutdown,
- 0, GFP_KERNEL);
- if (ret)
- return ret;
-
+ if (root_cache)
s->memcg_params.root_cache = root_cache;
- INIT_LIST_HEAD(&s->memcg_params.children_node);
- INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node);
- return 0;
- }
-
- slab_init_memcg_params(s);
-
- if (!memcg_nr_cache_ids)
- return 0;
-
- arr = kvzalloc(sizeof(struct memcg_cache_array) +
- memcg_nr_cache_ids * sizeof(void *),
- GFP_KERNEL);
- if (!arr)
- return -ENOMEM;
-
- RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
- return 0;
-}
-
-static void destroy_memcg_params(struct kmem_cache *s)
-{
- if (is_root_cache(s)) {
- kvfree(rcu_access_pointer(s->memcg_params.memcg_caches));
- } else {
- mem_cgroup_put(s->memcg_params.memcg);
- WRITE_ONCE(s->memcg_params.memcg, NULL);
- percpu_ref_exit(&s->memcg_params.refcnt);
- }
-}
-
-static void free_memcg_params(struct rcu_head *rcu)
-{
- struct memcg_cache_array *old;
-
- old = container_of(rcu, struct memcg_cache_array, rcu);
- kvfree(old);
-}
-
-static int update_memcg_params(struct kmem_cache *s, int new_array_size)
-{
- struct memcg_cache_array *old, *new;
-
- new = kvzalloc(sizeof(struct memcg_cache_array) +
- new_array_size * sizeof(void *), GFP_KERNEL);
- if (!new)
- return -ENOMEM;
-
- old = rcu_dereference_protected(s->memcg_params.memcg_caches,
- lockdep_is_held(&slab_mutex));
- if (old)
- memcpy(new->entries, old->entries,
- memcg_nr_cache_ids * sizeof(void *));
-
- rcu_assign_pointer(s->memcg_params.memcg_caches, new);
- if (old)
- call_rcu(&old->rcu, free_memcg_params);
- return 0;
-}
-
-int memcg_update_all_caches(int num_memcgs)
-{
- struct kmem_cache *s;
- int ret = 0;
-
- mutex_lock(&slab_mutex);
- list_for_each_entry(s, &slab_root_caches, root_caches_node) {
- ret = update_memcg_params(s, num_memcgs);
- /*
- * Instead of freeing the memory, we'll just leave the caches
- * up to this point in an updated state.
- */
- if (ret)
- break;
- }
- mutex_unlock(&slab_mutex);
- return ret;
+ else
+ slab_init_memcg_params(s);
}
-void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg)
+void memcg_link_cache(struct kmem_cache *s)
{
- if (is_root_cache(s)) {
+ if (is_root_cache(s))
list_add(&s->root_caches_node, &slab_root_caches);
- } else {
- css_get(&memcg->css);
- s->memcg_params.memcg = memcg;
- list_add(&s->memcg_params.children_node,
- &s->memcg_params.root_cache->memcg_params.children);
- list_add(&s->memcg_params.kmem_caches_node,
- &s->memcg_params.memcg->kmem_caches);
- }
}
static void memcg_unlink_cache(struct kmem_cache *s)
{
- if (is_root_cache(s)) {
+ if (is_root_cache(s))
list_del(&s->root_caches_node);
- } else {
- list_del(&s->memcg_params.children_node);
- list_del(&s->memcg_params.kmem_caches_node);
- }
}
#else
-static inline int init_memcg_params(struct kmem_cache *s,
- struct kmem_cache *root_cache)
-{
- return 0;
-}
-
-static inline void destroy_memcg_params(struct kmem_cache *s)
+static inline void init_memcg_params(struct kmem_cache *s,
+ struct kmem_cache *root_cache)
{
}
@@ -380,7 +275,7 @@ static struct kmem_cache *create_cache(const char *name,
unsigned int object_size, unsigned int align,
slab_flags_t flags, unsigned int useroffset,
unsigned int usersize, void (*ctor)(void *),
- struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+ struct kmem_cache *root_cache)
{
struct kmem_cache *s;
int err;
@@ -400,24 +295,20 @@ static struct kmem_cache *create_cache(const char *name,
s->useroffset = useroffset;
s->usersize = usersize;
- err = init_memcg_params(s, root_cache);
- if (err)
- goto out_free_cache;
-
+ init_memcg_params(s, root_cache);
err = __kmem_cache_create(s, flags);
if (err)
goto out_free_cache;
s->refcount = 1;
list_add(&s->list, &slab_caches);
- memcg_link_cache(s, memcg);
+ memcg_link_cache(s);
out:
if (err)
return ERR_PTR(err);
return s;
out_free_cache:
- destroy_memcg_params(s);
kmem_cache_free(kmem_cache, s);
goto out;
}
@@ -504,7 +395,7 @@ kmem_cache_create_usercopy(const char *name,
s = create_cache(cache_name, size,
calculate_alignment(flags, align, size),
- flags, useroffset, usersize, ctor, NULL, NULL);
+ flags, useroffset, usersize, ctor, NULL);
if (IS_ERR(s)) {
err = PTR_ERR(s);
kfree_const(cache_name);
@@ -629,51 +520,27 @@ static int shutdown_cache(struct kmem_cache *s)
#ifdef CONFIG_MEMCG_KMEM
/*
- * memcg_create_kmem_cache - Create a cache for a memory cgroup.
- * @memcg: The memory cgroup the new cache is for.
+ * memcg_create_kmem_cache - Create a cache for non-root memory cgroups.
* @root_cache: The parent of the new cache.
*
* This function attempts to create a kmem cache that will serve allocation
- * requests going from @memcg to @root_cache. The new cache inherits properties
- * from its parent.
+ * requests going all non-root memory cgroups to @root_cache. The new cache
+ * inherits properties from its parent.
*/
-void memcg_create_kmem_cache(struct mem_cgroup *memcg,
- struct kmem_cache *root_cache)
+void memcg_create_kmem_cache(struct kmem_cache *root_cache)
{
- static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
- struct cgroup_subsys_state *css = &memcg->css;
- struct memcg_cache_array *arr;
struct kmem_cache *s = NULL;
char *cache_name;
- int idx;
get_online_cpus();
get_online_mems();
mutex_lock(&slab_mutex);
- /*
- * The memory cgroup could have been offlined while the cache
- * creation work was pending.
- */
- if (memcg->kmem_state != KMEM_ONLINE)
+ if (root_cache->memcg_params.memcg_cache)
goto out_unlock;
- idx = memcg_cache_id(memcg);
- arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
- lockdep_is_held(&slab_mutex));
-
- /*
- * Since per-memcg caches are created asynchronously on first
- * allocation (see memcg_kmem_get_cache()), several threads can try to
- * create the same cache, but only one of them may succeed.
- */
- if (arr->entries[idx])
- goto out_unlock;
-
- cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
- cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name,
- css->serial_nr, memcg_name_buf);
+ cache_name = kasprintf(GFP_KERNEL, "%s-memcg", root_cache->name);
if (!cache_name)
goto out_unlock;
@@ -681,7 +548,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg,
root_cache->align,
root_cache->flags & CACHE_CREATE_MASK,
root_cache->useroffset, root_cache->usersize,
- root_cache->ctor, memcg, root_cache);
+ root_cache->ctor, root_cache);
/*
* If we could not create a memcg cache, do not complain, because
* that's not critical at all as we can always proceed with the root
@@ -698,7 +565,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg,
* initialized.
*/
smp_wmb();
- arr->entries[idx] = s;
+ root_cache->memcg_params.memcg_cache = s;
out_unlock:
mutex_unlock(&slab_mutex);
@@ -707,197 +574,18 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg,
put_online_cpus();
}
-static void kmemcg_workfn(struct work_struct *work)
-{
- struct kmem_cache *s = container_of(work, struct kmem_cache,
- memcg_params.work);
-
- get_online_cpus();
- get_online_mems();
-
- mutex_lock(&slab_mutex);
- s->memcg_params.work_fn(s);
- mutex_unlock(&slab_mutex);
-
- put_online_mems();
- put_online_cpus();
-}
-
-static void kmemcg_rcufn(struct rcu_head *head)
-{
- struct kmem_cache *s = container_of(head, struct kmem_cache,
- memcg_params.rcu_head);
-
- /*
- * We need to grab blocking locks. Bounce to ->work. The
- * work item shares the space with the RCU head and can't be
- * initialized earlier.
- */
- INIT_WORK(&s->memcg_params.work, kmemcg_workfn);
- queue_work(memcg_kmem_cache_wq, &s->memcg_params.work);
-}
-
-static void kmemcg_cache_shutdown_fn(struct kmem_cache *s)
-{
- WARN_ON(shutdown_cache(s));
-}
-
-static void kmemcg_cache_shutdown(struct percpu_ref *percpu_ref)
-{
- struct kmem_cache *s = container_of(percpu_ref, struct kmem_cache,
- memcg_params.refcnt);
- unsigned long flags;
-
- spin_lock_irqsave(&memcg_kmem_wq_lock, flags);
- if (s->memcg_params.root_cache->memcg_params.dying)
- goto unlock;
-
- s->memcg_params.work_fn = kmemcg_cache_shutdown_fn;
- INIT_WORK(&s->memcg_params.work, kmemcg_workfn);
- queue_work(memcg_kmem_cache_wq, &s->memcg_params.work);
-
-unlock:
- spin_unlock_irqrestore(&memcg_kmem_wq_lock, flags);
-}
-
-static void kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
-{
- __kmemcg_cache_deactivate_after_rcu(s);
- percpu_ref_kill(&s->memcg_params.refcnt);
-}
-
-static void kmemcg_cache_deactivate(struct kmem_cache *s)
-{
- if (WARN_ON_ONCE(is_root_cache(s)))
- return;
-
- __kmemcg_cache_deactivate(s);
- s->flags |= SLAB_DEACTIVATED;
-
- /*
- * memcg_kmem_wq_lock is used to synchronize memcg_params.dying
- * flag and make sure that no new kmem_cache deactivation tasks
- * are queued (see flush_memcg_workqueue() ).
- */
- spin_lock_irq(&memcg_kmem_wq_lock);
- if (s->memcg_params.root_cache->memcg_params.dying)
- goto unlock;
-
- s->memcg_params.work_fn = kmemcg_cache_deactivate_after_rcu;
- call_rcu(&s->memcg_params.rcu_head, kmemcg_rcufn);
-unlock:
- spin_unlock_irq(&memcg_kmem_wq_lock);
-}
-
-void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg,
- struct mem_cgroup *parent)
-{
- int idx;
- struct memcg_cache_array *arr;
- struct kmem_cache *s, *c;
- unsigned int nr_reparented;
-
- idx = memcg_cache_id(memcg);
-
- get_online_cpus();
- get_online_mems();
-
- mutex_lock(&slab_mutex);
- list_for_each_entry(s, &slab_root_caches, root_caches_node) {
- arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
- lockdep_is_held(&slab_mutex));
- c = arr->entries[idx];
- if (!c)
- continue;
-
- kmemcg_cache_deactivate(c);
- arr->entries[idx] = NULL;
- }
- nr_reparented = 0;
- list_for_each_entry(s, &memcg->kmem_caches,
- memcg_params.kmem_caches_node) {
- WRITE_ONCE(s->memcg_params.memcg, parent);
- css_put(&memcg->css);
- nr_reparented++;
- }
- if (nr_reparented) {
- list_splice_init(&memcg->kmem_caches,
- &parent->kmem_caches);
- css_get_many(&parent->css, nr_reparented);
- }
- mutex_unlock(&slab_mutex);
-
- put_online_mems();
- put_online_cpus();
-}
-
static int shutdown_memcg_caches(struct kmem_cache *s)
{
- struct memcg_cache_array *arr;
- struct kmem_cache *c, *c2;
- LIST_HEAD(busy);
- int i;
-
BUG_ON(!is_root_cache(s));
- /*
- * First, shutdown active caches, i.e. caches that belong to online
- * memory cgroups.
- */
- arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
- lockdep_is_held(&slab_mutex));
- for_each_memcg_cache_index(i) {
- c = arr->entries[i];
- if (!c)
- continue;
- if (shutdown_cache(c))
- /*
- * The cache still has objects. Move it to a temporary
- * list so as not to try to destroy it for a second
- * time while iterating over inactive caches below.
- */
- list_move(&c->memcg_params.children_node, &busy);
- else
- /*
- * The cache is empty and will be destroyed soon. Clear
- * the pointer to it in the memcg_caches array so that
- * it will never be accessed even if the root cache
- * stays alive.
- */
- arr->entries[i] = NULL;
- }
-
- /*
- * Second, shutdown all caches left from memory cgroups that are now
- * offline.
- */
- list_for_each_entry_safe(c, c2, &s->memcg_params.children,
- memcg_params.children_node)
- shutdown_cache(c);
-
- list_splice(&busy, &s->memcg_params.children);
+ if (s->memcg_params.memcg_cache)
+ WARN_ON(shutdown_cache(s->memcg_params.memcg_cache));
- /*
- * A cache being destroyed must be empty. In particular, this means
- * that all per memcg caches attached to it must be empty too.
- */
- if (!list_empty(&s->memcg_params.children))
- return -EBUSY;
return 0;
}
static void flush_memcg_workqueue(struct kmem_cache *s)
{
- spin_lock_irq(&memcg_kmem_wq_lock);
- s->memcg_params.dying = true;
- spin_unlock_irq(&memcg_kmem_wq_lock);
-
- /*
- * SLAB and SLUB deactivate the kmem_caches through call_rcu. Make
- * sure all registered rcu callbacks have been invoked.
- */
- rcu_barrier();
-
/*
* SLAB and SLUB create memcg kmem_caches through workqueue and SLUB
* deactivates the memcg kmem_caches through workqueue. Make sure all
@@ -905,18 +593,6 @@ static void flush_memcg_workqueue(struct kmem_cache *s)
*/
if (likely(memcg_kmem_cache_wq))
flush_workqueue(memcg_kmem_cache_wq);
-
- /*
- * If we're racing with children kmem_cache deactivation, it might
- * take another rcu grace period to complete their destruction.
- * At this moment the corresponding percpu_ref_kill() call should be
- * done, but it might take another rcu grace period to complete
- * switching to the atomic mode.
- * Please, note that we check without grabbing the slab_mutex. It's safe
- * because at this moment the children list can't grow.
- */
- if (!list_empty(&s->memcg_params.children))
- rcu_barrier();
}
#else
static inline int shutdown_memcg_caches(struct kmem_cache *s)
@@ -932,7 +608,6 @@ static inline void flush_memcg_workqueue(struct kmem_cache *s)
void slab_kmem_cache_release(struct kmem_cache *s)
{
__kmem_cache_release(s);
- destroy_memcg_params(s);
kfree_const(s->name);
kmem_cache_free(kmem_cache, s);
}
@@ -996,7 +671,7 @@ int kmem_cache_shrink(struct kmem_cache *cachep)
EXPORT_SYMBOL(kmem_cache_shrink);
/**
- * kmem_cache_shrink_all - shrink a cache and all memcg caches for root cache
+ * kmem_cache_shrink_all - shrink root and memcg caches
* @s: The cache pointer
*/
void kmem_cache_shrink_all(struct kmem_cache *s)
@@ -1013,21 +688,11 @@ void kmem_cache_shrink_all(struct kmem_cache *s)
kasan_cache_shrink(s);
__kmem_cache_shrink(s);
- /*
- * We have to take the slab_mutex to protect from the memcg list
- * modification.
- */
- mutex_lock(&slab_mutex);
- for_each_memcg_cache(c, s) {
- /*
- * Don't need to shrink deactivated memcg caches.
- */
- if (s->flags & SLAB_DEACTIVATED)
- continue;
+ c = memcg_cache(s);
+ if (c) {
kasan_cache_shrink(c);
__kmem_cache_shrink(c);
}
- mutex_unlock(&slab_mutex);
put_online_mems();
put_online_cpus();
}
@@ -1082,7 +747,7 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
create_boot_cache(s, name, size, flags, useroffset, usersize);
list_add(&s->list, &slab_caches);
- memcg_link_cache(s, NULL);
+ memcg_link_cache(s);
s->refcount = 1;
return s;
}
@@ -1445,7 +1110,8 @@ memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
if (!is_root_cache(s))
return;
- for_each_memcg_cache(c, s) {
+ c = memcg_cache(s);
+ if (c) {
memset(&sinfo, 0, sizeof(sinfo));
get_slabinfo(c, &sinfo);
@@ -1576,7 +1242,7 @@ module_init(slab_proc_init);
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_MEMCG_KMEM)
/*
- * Display information about kmem caches that have child memcg caches.
+ * Display information about kmem caches that have memcg cache.
*/
static int memcg_slabinfo_show(struct seq_file *m, void *unused)
{
@@ -1588,9 +1254,9 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused)
seq_puts(m, " <active_slabs> <num_slabs>\n");
list_for_each_entry(s, &slab_root_caches, root_caches_node) {
/*
- * Skip kmem caches that don't have any memcg children.
+ * Skip kmem caches that don't have the memcg cache.
*/
- if (list_empty(&s->memcg_params.children))
+ if (!s->memcg_params.memcg_cache)
continue;
memset(&sinfo, 0, sizeof(sinfo));
@@ -1599,23 +1265,13 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused)
cache_name(s), sinfo.active_objs, sinfo.num_objs,
sinfo.active_slabs, sinfo.num_slabs);
- for_each_memcg_cache(c, s) {
- struct cgroup_subsys_state *css;
- char *status = "";
-
- css = &c->memcg_params.memcg->css;
- if (!(css->flags & CSS_ONLINE))
- status = ":dead";
- else if (c->flags & SLAB_DEACTIVATED)
- status = ":deact";
-
- memset(&sinfo, 0, sizeof(sinfo));
- get_slabinfo(c, &sinfo);
- seq_printf(m, "%-17s %4d%-6s %6lu %6lu %6lu %6lu\n",
- cache_name(c), css->id, status,
- sinfo.active_objs, sinfo.num_objs,
- sinfo.active_slabs, sinfo.num_slabs);
- }
+ c = s->memcg_params.memcg_cache;
+ memset(&sinfo, 0, sizeof(sinfo));
+ get_slabinfo(c, &sinfo);
+ seq_printf(m, "%-17s %4d %6lu %6lu %6lu %6lu\n",
+ cache_name(c), root_mem_cgroup->css.id,
+ sinfo.active_objs, sinfo.num_objs,
+ sinfo.active_slabs, sinfo.num_slabs);
}
mutex_unlock(&slab_mutex);
return 0;
diff --git a/mm/slub.c b/mm/slub.c
index 7007eceac4c4..6761e40e2c2e 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4136,36 +4136,6 @@ int __kmem_cache_shrink(struct kmem_cache *s)
return ret;
}
-#ifdef CONFIG_MEMCG
-void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
-{
- /*
- * Called with all the locks held after a sched RCU grace period.
- * Even if @s becomes empty after shrinking, we can't know that @s
- * doesn't have allocations already in-flight and thus can't
- * destroy @s until the associated memcg is released.
- *
- * However, let's remove the sysfs files for empty caches here.
- * Each cache has a lot of interface files which aren't
- * particularly useful for empty draining caches; otherwise, we can
- * easily end up with millions of unnecessary sysfs files on
- * systems which have a lot of memory and transient cgroups.
- */
- if (!__kmem_cache_shrink(s))
- sysfs_slab_remove(s);
-}
-
-void __kmemcg_cache_deactivate(struct kmem_cache *s)
-{
- /*
- * Disable empty slabs caching. Used to avoid pinning offline
- * memory cgroups by kmem pages that can be freed.
- */
- slub_set_cpu_partial(s, 0);
- s->min_partial = 0;
-}
-#endif /* CONFIG_MEMCG */
-
static int slab_mem_going_offline_callback(void *arg)
{
struct kmem_cache *s;
@@ -4322,7 +4292,7 @@ static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)
}
slab_init_memcg_params(s);
list_add(&s->list, &slab_caches);
- memcg_link_cache(s, NULL);
+ memcg_link_cache(s);
return s;
}
@@ -4390,7 +4360,8 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
s->object_size = max(s->object_size, size);
s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
- for_each_memcg_cache(c, s) {
+ c = memcg_cache(s);
+ if (c) {
c->object_size = s->object_size;
c->inuse = max(c->inuse, ALIGN(size, sizeof(void *)));
}
@@ -5645,7 +5616,8 @@ static ssize_t slab_attr_store(struct kobject *kobj,
* directly either failed or succeeded, in which case we loop
* through the descendants with best-effort propagation.
*/
- for_each_memcg_cache(c, s)
+ c = memcg_cache(s);
+ if (c)
attribute->store(c, buf, len);
mutex_unlock(&slab_mutex);
}
--
2.25.4
The memcg_kmem_get_cache() function became really trivial,
so let's just inline it into the single call point:
memcg_slab_pre_alloc_hook().
It will make the code less bulky and can also help the compiler
to generate a better code.
Signed-off-by: Roman Gushchin <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
---
include/linux/memcontrol.h | 2 --
mm/memcontrol.c | 25 +------------------------
mm/slab.h | 11 +++++++++--
mm/slab_common.c | 2 +-
4 files changed, 11 insertions(+), 29 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index ed0d2ac6a5d2..eede46c43573 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1403,8 +1403,6 @@ static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
}
#endif
-struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
-
#ifdef CONFIG_MEMCG_KMEM
int __memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp,
unsigned int nr_pages);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2695cdc15baa..09a84326ead1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -393,7 +393,7 @@ void memcg_put_cache_ids(void)
/*
* A lot of the calls to the cache allocation functions are expected to be
- * inlined by the compiler. Since the calls to memcg_kmem_get_cache are
+ * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are
* conditional to this static branch, we'll have to allow modules that does
* kmem_cache_alloc and the such to see this symbol as well
*/
@@ -2900,29 +2900,6 @@ static void memcg_free_cache_id(int id)
ida_simple_remove(&memcg_cache_ida, id);
}
-/**
- * memcg_kmem_get_cache: select memcg or root cache for allocation
- * @cachep: the original global kmem cache
- *
- * Return the kmem_cache we're supposed to use for a slab allocation.
- *
- * If the cache does not exist yet, if we are the first user of it, we
- * create it asynchronously in a workqueue and let the current allocation
- * go through with the original cache.
- */
-struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep)
-{
- struct kmem_cache *memcg_cachep;
-
- memcg_cachep = READ_ONCE(cachep->memcg_params.memcg_cache);
- if (unlikely(!memcg_cachep)) {
- queue_work(system_wq, &cachep->memcg_params.work);
- return cachep;
- }
-
- return memcg_cachep;
-}
-
/**
* __memcg_kmem_charge: charge a number of kernel pages to a memcg
* @memcg: memory cgroup to charge
diff --git a/mm/slab.h b/mm/slab.h
index c6c7987dfd85..f4033298a776 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -333,9 +333,16 @@ static inline struct kmem_cache *memcg_slab_pre_alloc_hook(struct kmem_cache *s,
if (memcg_kmem_bypass())
return s;
- cachep = memcg_kmem_get_cache(s);
- if (is_root_cache(cachep))
+ cachep = READ_ONCE(s->memcg_params.memcg_cache);
+ if (unlikely(!cachep)) {
+ /*
+ * If memcg cache does not exist yet, we schedule it's
+ * asynchronous creation and let the current allocation
+ * go through with the root cache.
+ */
+ queue_work(system_wq, &s->memcg_params.work);
return s;
+ }
objcg = get_obj_cgroup_from_current();
if (!objcg)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 10aa2acb84ca..f8874a159637 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -568,7 +568,7 @@ void memcg_create_kmem_cache(struct kmem_cache *root_cache)
}
/*
- * Since readers won't lock (see memcg_kmem_get_cache()), we need a
+ * Since readers won't lock (see memcg_slab_pre_alloc_hook()), we need a
* barrier here to ensure nobody will see the kmem_cache partially
* initialized.
*/
--
2.25.4
On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
>
> This is v6 of the slab cgroup controller rework.
>
> The patchset moves the accounting from the page level to the object
> level. It allows to share slab pages between memory cgroups.
> This leads to a significant win in the slab utilization (up to 45%)
> and the corresponding drop in the total kernel memory footprint.
Is this based on just SLUB or does this have a similar impact on SLAB as well?
> The reduced number of unmovable slab pages should also have a positive
> effect on the memory fragmentation.
That would be awesome. We have seen fragmentation getting very bad on
system (or node) level memory pressure. Is that the same for you?
>
> The patchset makes the slab accounting code simpler: there is no more
> need in the complicated dynamic creation and destruction of per-cgroup
> slab caches, all memory cgroups use a global set of shared slab caches.
> The lifetime of slab caches is not more connected to the lifetime
> of memory cgroups.
>
> The more precise accounting does require more CPU, however in practice
> the difference seems to be negligible. We've been using the new slab
> controller in Facebook production for several months with different
> workloads and haven't seen any noticeable regressions. What we've seen
> were memory savings in order of 1 GB per host (it varied heavily depending
> on the actual workload, size of RAM, number of CPUs, memory pressure, etc).
>
> The third version of the patchset added yet another step towards
> the simplification of the code: sharing of slab caches between
> accounted and non-accounted allocations. It comes with significant
> upsides (most noticeable, a complete elimination of dynamic slab caches
> creation) but not without some regression risks, so this change sits
> on top of the patchset and is not completely merged in. So in the unlikely
> event of a noticeable performance regression it can be reverted separately.
>
Have you performed any [perf] testing on SLAB with this patchset?
> v6:
> 1) rebased on top of the mm tree
> 2) removed a redundant check from cache_from_obj(), suggested by Vlastimil
>
> v5:
> 1) fixed a build error, spotted by Vlastimil
> 2) added a comment about memcg->nr_charged_bytes, asked by Johannes
> 3) added missed acks and reviews
>
> v4:
> 1) rebased on top of the mm tree, some fixes here and there
> 2) merged obj_to_index() with slab_index(), suggested by Vlastimil
> 3) changed objects_per_slab() to a better objects_per_slab_page(),
> suggested by Vlastimil
> 4) other minor fixes and changes
>
> v3:
> 1) added a patch that switches to a global single set of kmem_caches
> 2) kmem API clean up dropped, because if has been already merged
> 3) byte-sized slab vmstat API over page-sized global counters and
> bytes-sized memcg/lruvec counters
> 3) obj_cgroup refcounting simplifications and other minor fixes
> 4) other minor changes
>
> v2:
> 1) implemented re-layering and renaming suggested by Johannes,
> added his patch to the set. Thanks!
> 2) fixed the issue discovered by Bharata B Rao. Thanks!
> 3) added kmem API clean up part
> 4) added slab/memcg follow-up clean up part
> 5) fixed a couple of issues discovered by internal testing on FB fleet.
> 6) added kselftests
> 7) included metadata into the charge calculation
> 8) refreshed commit logs, regrouped patches, rebased onto mm tree, etc
>
> v1:
> 1) fixed a bug in zoneinfo_show_print()
> 2) added some comments to the subpage charging API, a minor fix
> 3) separated memory.kmem.slabinfo deprecation into a separate patch,
> provided a drgn-based replacement
> 4) rebased on top of the current mm tree
>
> RFC:
> https://lwn.net/Articles/798605/
>
>
> Johannes Weiner (1):
> mm: memcontrol: decouple reference counting from page accounting
>
> Roman Gushchin (18):
> mm: memcg: factor out memcg- and lruvec-level changes out of
> __mod_lruvec_state()
> mm: memcg: prepare for byte-sized vmstat items
> mm: memcg: convert vmstat slab counters to bytes
> mm: slub: implement SLUB version of obj_to_index()
> mm: memcg/slab: obj_cgroup API
> mm: memcg/slab: allocate obj_cgroups for non-root slab pages
> mm: memcg/slab: save obj_cgroup for non-root slab objects
> mm: memcg/slab: charge individual slab objects instead of pages
> mm: memcg/slab: deprecate memory.kmem.slabinfo
> mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h
> mm: memcg/slab: use a single set of kmem_caches for all accounted
> allocations
> mm: memcg/slab: simplify memcg cache creation
> mm: memcg/slab: remove memcg_kmem_get_cache()
> mm: memcg/slab: deprecate slab_root_caches
> mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo()
> mm: memcg/slab: use a single set of kmem_caches for all allocations
> kselftests: cgroup: add kernel memory accounting tests
> tools/cgroup: add memcg_slabinfo.py tool
>
> drivers/base/node.c | 6 +-
> fs/proc/meminfo.c | 4 +-
> include/linux/memcontrol.h | 85 ++-
> include/linux/mm_types.h | 5 +-
> include/linux/mmzone.h | 24 +-
> include/linux/slab.h | 5 -
> include/linux/slab_def.h | 9 +-
> include/linux/slub_def.h | 31 +-
> include/linux/vmstat.h | 14 +-
> kernel/power/snapshot.c | 2 +-
> mm/memcontrol.c | 608 +++++++++++--------
> mm/oom_kill.c | 2 +-
> mm/page_alloc.c | 8 +-
> mm/slab.c | 70 +--
> mm/slab.h | 372 +++++-------
> mm/slab_common.c | 643 +--------------------
> mm/slob.c | 12 +-
> mm/slub.c | 229 +-------
> mm/vmscan.c | 3 +-
> mm/vmstat.c | 30 +-
> mm/workingset.c | 6 +-
> tools/cgroup/memcg_slabinfo.py | 226 ++++++++
> tools/testing/selftests/cgroup/.gitignore | 1 +
> tools/testing/selftests/cgroup/Makefile | 2 +
> tools/testing/selftests/cgroup/test_kmem.c | 382 ++++++++++++
> 25 files changed, 1374 insertions(+), 1405 deletions(-)
> create mode 100755 tools/cgroup/memcg_slabinfo.py
> create mode 100644 tools/testing/selftests/cgroup/test_kmem.c
>
> --
> 2.25.4
>
On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> >
> > This is v6 of the slab cgroup controller rework.
> >
> > The patchset moves the accounting from the page level to the object
> > level. It allows to share slab pages between memory cgroups.
> > This leads to a significant win in the slab utilization (up to 45%)
> > and the corresponding drop in the total kernel memory footprint.
>
> Is this based on just SLUB or does this have a similar impact on SLAB as well?
The numbers for SLAB are less impressive than for SLUB (I guess per-cpu partial
lists add to the problem), but also in double digits of percents.
>
> > The reduced number of unmovable slab pages should also have a positive
> > effect on the memory fragmentation.
>
> That would be awesome. We have seen fragmentation getting very bad on
> system (or node) level memory pressure. Is that the same for you?
Well, we didn't have any specific problems with the fragmentation,
but generally speaking reducing the size of unmovable memory by ~40%
should have a positive effect.
>
> >
> > The patchset makes the slab accounting code simpler: there is no more
> > need in the complicated dynamic creation and destruction of per-cgroup
> > slab caches, all memory cgroups use a global set of shared slab caches.
> > The lifetime of slab caches is not more connected to the lifetime
> > of memory cgroups.
> >
> > The more precise accounting does require more CPU, however in practice
> > the difference seems to be negligible. We've been using the new slab
> > controller in Facebook production for several months with different
> > workloads and haven't seen any noticeable regressions. What we've seen
> > were memory savings in order of 1 GB per host (it varied heavily depending
> > on the actual workload, size of RAM, number of CPUs, memory pressure, etc).
> >
> > The third version of the patchset added yet another step towards
> > the simplification of the code: sharing of slab caches between
> > accounted and non-accounted allocations. It comes with significant
> > upsides (most noticeable, a complete elimination of dynamic slab caches
> > creation) but not without some regression risks, so this change sits
> > on top of the patchset and is not completely merged in. So in the unlikely
> > event of a noticeable performance regression it can be reverted separately.
> >
>
> Have you performed any [perf] testing on SLAB with this patchset?
The accounting part is the same for SLAB and SLUB, so there should be no
significant difference. I've checked that it compiles, boots and passes
kselftests. And that memory savings are there.
Thanks!
On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
>
> On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > >
[...]
> >
> > Have you performed any [perf] testing on SLAB with this patchset?
>
> The accounting part is the same for SLAB and SLUB, so there should be no
> significant difference. I've checked that it compiles, boots and passes
> kselftests. And that memory savings are there.
>
What about performance? Also you mentioned that sharing kmem-cache
between accounted and non-accounted can have additional overhead. Any
difference between SLAB and SLUB for such a case?
On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> >
> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > > >
> [...]
> > >
> > > Have you performed any [perf] testing on SLAB with this patchset?
> >
> > The accounting part is the same for SLAB and SLUB, so there should be no
> > significant difference. I've checked that it compiles, boots and passes
> > kselftests. And that memory savings are there.
> >
>
> What about performance? Also you mentioned that sharing kmem-cache
> between accounted and non-accounted can have additional overhead. Any
> difference between SLAB and SLUB for such a case?
Not really.
Sharing a single set of caches adds some overhead to root- and non-accounted
allocations, which is something I've tried hard to avoid in my original version.
But I have to admit, it allows to simplify and remove a lot of code, and here
it's hard to argue with Johanness, who pushed on this design.
With performance testing it's not that easy, because it's not obvious what
we wanna test. Obviously, per-object accounting is more expensive, and
measuring something like 1000000 allocations and deallocations in a line from
a single kmem_cache will show a regression. But in the real world the relative
cost of allocations is usually low, and we can get some benefits from a smaller
working set and from having shared kmem_cache objects cache hot.
Not speaking about some extra memory and the fragmentation reduction.
We've done an extensive testing of the original version in Facebook production,
and we haven't noticed any regressions so far. But I have to admit, we were
using an original version with two sets of kmem_caches.
If you have any specific tests in mind, I can definitely run them. Or if you
can help with the performance evaluation, I'll appreciate it a lot.
Thanks!
On 6/17/20 5:32 AM, Roman Gushchin wrote:
> On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
>> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
>> >
>> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
>> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
>> > > >
>> [...]
>> > >
>> > > Have you performed any [perf] testing on SLAB with this patchset?
>> >
>> > The accounting part is the same for SLAB and SLUB, so there should be no
>> > significant difference. I've checked that it compiles, boots and passes
>> > kselftests. And that memory savings are there.
>> >
>>
>> What about performance? Also you mentioned that sharing kmem-cache
>> between accounted and non-accounted can have additional overhead. Any
>> difference between SLAB and SLUB for such a case?
>
> Not really.
>
> Sharing a single set of caches adds some overhead to root- and non-accounted
> allocations, which is something I've tried hard to avoid in my original version.
> But I have to admit, it allows to simplify and remove a lot of code, and here
> it's hard to argue with Johanness, who pushed on this design.
>
> With performance testing it's not that easy, because it's not obvious what
> we wanna test. Obviously, per-object accounting is more expensive, and
> measuring something like 1000000 allocations and deallocations in a line from
> a single kmem_cache will show a regression. But in the real world the relative
> cost of allocations is usually low, and we can get some benefits from a smaller
> working set and from having shared kmem_cache objects cache hot.
> Not speaking about some extra memory and the fragmentation reduction.
>
> We've done an extensive testing of the original version in Facebook production,
> and we haven't noticed any regressions so far. But I have to admit, we were
> using an original version with two sets of kmem_caches.
>
> If you have any specific tests in mind, I can definitely run them. Or if you
> can help with the performance evaluation, I'll appreciate it a lot.
Jesper provided some pointers here [1], it would be really great if you could
run at least those microbenchmarks. With mmtests it's the major question of
which subset/profiles to run, maybe the referenced commits provide some hints,
or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
[1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
> Thanks!
>
On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > Not really.
> >
> > Sharing a single set of caches adds some overhead to root- and non-accounted
> > allocations, which is something I've tried hard to avoid in my original version.
> > But I have to admit, it allows to simplify and remove a lot of code, and here
> > it's hard to argue with Johanness, who pushed on this design.
> >
> > With performance testing it's not that easy, because it's not obvious what
> > we wanna test. Obviously, per-object accounting is more expensive, and
> > measuring something like 1000000 allocations and deallocations in a line from
> > a single kmem_cache will show a regression. But in the real world the relative
> > cost of allocations is usually low, and we can get some benefits from a smaller
> > working set and from having shared kmem_cache objects cache hot.
> > Not speaking about some extra memory and the fragmentation reduction.
> >
> > We've done an extensive testing of the original version in Facebook production,
> > and we haven't noticed any regressions so far. But I have to admit, we were
> > using an original version with two sets of kmem_caches.
> >
> > If you have any specific tests in mind, I can definitely run them. Or if you
> > can help with the performance evaluation, I'll appreciate it a lot.
>
> Jesper provided some pointers here [1], it would be really great if you could
> run at least those microbenchmarks. With mmtests it's the major question of
> which subset/profiles to run, maybe the referenced commits provide some hints,
> or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
>
Last time the list of mmtests configurations I used for a basic
comparison were
db-pgbench-timed-ro-small-ext4
db-pgbench-timed-ro-small-xfs
io-dbench4-async-ext4
io-dbench4-async-xfs
io-bonnie-dir-async-ext4
io-bonnie-dir-async-xfs
io-bonnie-file-async-ext4
io-bonnie-file-async-xfs
io-fsmark-xfsrepair-xfs
io-metadata-xfs
network-netperf-unbound
network-netperf-cross-node
network-netperf-cross-socket
network-sockperf-unbound
network-netperf-unix-unbound
network-netpipe
network-tbench
pagereclaim-shrinker-ext4
scheduler-unbound
scheduler-forkintensive
workload-kerndevel-xfs
workload-thpscale-madvhugepage-xfs
workload-thpscale-xfs
Some were more valid than others in terms of doing an evaluation. I
followed up later with a more comprehensive comparison but that was
overkill.
Each time I did a slab/slub comparison in the past, I had to reverify
the rate that kmem_cache_* functions were actually being called as the
pattern can change over time even for the same workload. A comparison
gets more complicated when comparing cgroups as ideally there would be
workloads running in multiple group but that gets complex and I think
it's reasonable to just test the "basic" case without cgroups.
--
Mel Gorman
SUSE Labs
On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> >
> > This is v6 of the slab cgroup controller rework.
> >
> > The patchset moves the accounting from the page level to the object
> > level. It allows to share slab pages between memory cgroups.
> > This leads to a significant win in the slab utilization (up to 45%)
> > and the corresponding drop in the total kernel memory footprint.
>
> Is this based on just SLUB or does this have a similar impact on SLAB as well?
Just got some fresh numbers on my desktop running 5.8-rc1 + slab controller v6.
It's 8-cores Ryzen 1700 with 32 GB RAM running Fedora 32.
I measured the size of slab memory just after logging into the system.
SLUB SLAB
Original: 463232 kB 312880 kB
Patched: 194840 kB 193392 kB
-58% -38%
Plus perpcu memory usage is also a bit lower.
Thanks!
On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> On 6/17/20 5:32 AM, Roman Gushchin wrote:
> > On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> >> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> >> >
> >> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> >> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> >> > > >
> >> [...]
> >> > >
> >> > > Have you performed any [perf] testing on SLAB with this patchset?
> >> >
> >> > The accounting part is the same for SLAB and SLUB, so there should be no
> >> > significant difference. I've checked that it compiles, boots and passes
> >> > kselftests. And that memory savings are there.
> >> >
> >>
> >> What about performance? Also you mentioned that sharing kmem-cache
> >> between accounted and non-accounted can have additional overhead. Any
> >> difference between SLAB and SLUB for such a case?
> >
> > Not really.
> >
> > Sharing a single set of caches adds some overhead to root- and non-accounted
> > allocations, which is something I've tried hard to avoid in my original version.
> > But I have to admit, it allows to simplify and remove a lot of code, and here
> > it's hard to argue with Johanness, who pushed on this design.
> >
> > With performance testing it's not that easy, because it's not obvious what
> > we wanna test. Obviously, per-object accounting is more expensive, and
> > measuring something like 1000000 allocations and deallocations in a line from
> > a single kmem_cache will show a regression. But in the real world the relative
> > cost of allocations is usually low, and we can get some benefits from a smaller
> > working set and from having shared kmem_cache objects cache hot.
> > Not speaking about some extra memory and the fragmentation reduction.
> >
> > We've done an extensive testing of the original version in Facebook production,
> > and we haven't noticed any regressions so far. But I have to admit, we were
> > using an original version with two sets of kmem_caches.
> >
> > If you have any specific tests in mind, I can definitely run them. Or if you
> > can help with the performance evaluation, I'll appreciate it a lot.
>
> Jesper provided some pointers here [1], it would be really great if you could
> run at least those microbenchmarks. With mmtests it's the major question of
> which subset/profiles to run, maybe the referenced commits provide some hints,
> or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
>
> [1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
Oh, Jesper, I'm really sorry, somehow I missed your mail.
Thank you, Vlastimil, for pointing at it.
I've got some results (slab_bulk_test01), but honestly I fail to interpret them.
I ran original vs patched with SLUB and SLAB, each test several times and picked
3 which looked most consistently. But it still looks very noisy.
I ran them on my desktop (8-core Ryzen 1700, 16 GB RAM, Fedora 32),
it's 5.8-rc1 + slab controller v6 vs 5.8-rc1 (default config from Fedora 32).
How should I interpret this data?
--
SLUB:
Patched:
[ 444.395174] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.773 ns (step:0) - (measurement period time:0.077335091 sec time_interval:77335091) - (invoke count:100000000 tsc_interval:231555960)
[ 445.012669] time_bench: Type:kmem fastpath reuse Per elem: 184 cycles(tsc) 61.747 ns (step:0) - (measurement period time:0.617475365 sec time_interval:617475365) - (invoke count:10000000 tsc_interval:1848850440)
[ 445.703843] time_bench: Type:kmem bulk_fallback Per elem: 206 cycles(tsc) 69.115 ns (step:1) - (measurement period time:0.691150675 sec time_interval:691150675) - (invoke count:10000000 tsc_interval:2069450250)
[ 446.329396] time_bench: Type:kmem bulk_quick_reuse Per elem: 187 cycles(tsc) 62.554 ns (step:1) - (measurement period time:0.625541838 sec time_interval:625541838) - (invoke count:10000000 tsc_interval:1873003020)
[ 446.975616] time_bench: Type:kmem bulk_fallback Per elem: 193 cycles(tsc) 64.622 ns (step:2) - (measurement period time:0.646223732 sec time_interval:646223732) - (invoke count:10000000 tsc_interval:1934929440)
[ 447.345512] time_bench: Type:kmem bulk_quick_reuse Per elem: 110 cycles(tsc) 36.988 ns (step:2) - (measurement period time:0.369885352 sec time_interval:369885352) - (invoke count:10000000 tsc_interval:1107514050)
[ 447.986272] time_bench: Type:kmem bulk_fallback Per elem: 191 cycles(tsc) 64.075 ns (step:3) - (measurement period time:0.640756304 sec time_interval:640756304) - (invoke count:9999999 tsc_interval:1918559070)
[ 448.282163] time_bench: Type:kmem bulk_quick_reuse Per elem: 88 cycles(tsc) 29.586 ns (step:3) - (measurement period time:0.295866328 sec time_interval:295866328) - (invoke count:9999999 tsc_interval:885885270)
[ 448.623183] time_bench: Type:kmem bulk_fallback Per elem: 102 cycles(tsc) 34.100 ns (step:4) - (measurement period time:0.341005290 sec time_interval:341005290) - (invoke count:10000000 tsc_interval:1021040820)
[ 448.930228] time_bench: Type:kmem bulk_quick_reuse Per elem: 91 cycles(tsc) 30.702 ns (step:4) - (measurement period time:0.307020500 sec time_interval:307020500) - (invoke count:10000000 tsc_interval:919282860)
[ 449.739697] time_bench: Type:kmem bulk_fallback Per elem: 242 cycles(tsc) 80.946 ns (step:8) - (measurement period time:0.809465825 sec time_interval:809465825) - (invoke count:10000000 tsc_interval:2423710560)
[ 449.848110] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.836 ns (step:8) - (measurement period time:0.108363638 sec time_interval:108363638) - (invoke count:10000000 tsc_interval:324462540)
[ 450.617892] time_bench: Type:kmem bulk_fallback Per elem: 230 cycles(tsc) 76.978 ns (step:16) - (measurement period time:0.769783892 sec time_interval:769783892) - (invoke count:10000000 tsc_interval:2304894090)
[ 450.719556] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.164 ns (step:16) - (measurement period time:0.101645837 sec time_interval:101645837) - (invoke count:10000000 tsc_interval:304348440)
[ 451.025387] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.580 ns (step:30) - (measurement period time:0.305803321 sec time_interval:305803321) - (invoke count:9999990 tsc_interval:915639450)
[ 451.277708] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.229 ns (step:30) - (measurement period time:0.252294821 sec time_interval:252294821) - (invoke count:9999990 tsc_interval:755422110)
[ 451.709305] time_bench: Type:kmem bulk_fallback Per elem: 129 cycles(tsc) 43.158 ns (step:32) - (measurement period time:0.431581619 sec time_interval:431581619) - (invoke count:10000000 tsc_interval:1292245320)
[ 451.810686] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.135 ns (step:32) - (measurement period time:0.101357841 sec time_interval:101357841) - (invoke count:10000000 tsc_interval:303485250)
[ 452.186138] time_bench: Type:kmem bulk_fallback Per elem: 112 cycles(tsc) 37.545 ns (step:34) - (measurement period time:0.375453243 sec time_interval:375453243) - (invoke count:9999978 tsc_interval:1124185320)
[ 452.304950] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.880 ns (step:34) - (measurement period time:0.118800736 sec time_interval:118800736) - (invoke count:9999978 tsc_interval:355713360)
[ 452.658607] time_bench: Type:kmem bulk_fallback Per elem: 105 cycles(tsc) 35.362 ns (step:48) - (measurement period time:0.353623065 sec time_interval:353623065) - (invoke count:9999984 tsc_interval:1058820960)
[ 452.891623] time_bench: Type:kmem bulk_quick_reuse Per elem: 69 cycles(tsc) 23.298 ns (step:48) - (measurement period time:0.232988291 sec time_interval:232988291) - (invoke count:9999984 tsc_interval:697614570)
[ 453.237406] time_bench: Type:kmem bulk_fallback Per elem: 103 cycles(tsc) 34.578 ns (step:64) - (measurement period time:0.345780444 sec time_interval:345780444) - (invoke count:10000000 tsc_interval:1035338790)
[ 453.344946] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.750 ns (step:64) - (measurement period time:0.107500964 sec time_interval:107500964) - (invoke count:10000000 tsc_interval:321880290)
[ 454.249297] time_bench: Type:kmem bulk_fallback Per elem: 270 cycles(tsc) 90.434 ns (step:128) - (measurement period time:0.904340126 sec time_interval:904340126) - (invoke count:10000000 tsc_interval:2707784610)
[ 454.582548] time_bench: Type:kmem bulk_quick_reuse Per elem: 99 cycles(tsc) 33.322 ns (step:128) - (measurement period time:0.333226211 sec time_interval:333226211) - (invoke count:10000000 tsc_interval:997748760)
[ 454.965002] time_bench: Type:kmem bulk_fallback Per elem: 114 cycles(tsc) 38.241 ns (step:158) - (measurement period time:0.382415227 sec time_interval:382415227) - (invoke count:9999978 tsc_interval:1145031120)
[ 455.314105] time_bench: Type:kmem bulk_quick_reuse Per elem: 104 cycles(tsc) 34.908 ns (step:158) - (measurement period time:0.349080430 sec time_interval:349080430) - (invoke count:9999978 tsc_interval:1045219530)
[ 455.699089] time_bench: Type:kmem bulk_fallback Per elem: 115 cycles(tsc) 38.495 ns (step:250) - (measurement period time:0.384953654 sec time_interval:384953654) - (invoke count:10000000 tsc_interval:1152631920)
[ 456.104244] time_bench: Type:kmem bulk_quick_reuse Per elem: 121 cycles(tsc) 40.513 ns (step:250) - (measurement period time:0.405138149 sec time_interval:405138149) - (invoke count:10000000 tsc_interval:1213068180)
[ 465.696654] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.772 ns (step:0) - (measurement period time:0.077270577 sec time_interval:77270577) - (invoke count:100000000 tsc_interval:231363840)
[ 466.290176] time_bench: Type:kmem fastpath reuse Per elem: 177 cycles(tsc) 59.349 ns (step:0) - (measurement period time:0.593496780 sec time_interval:593496780) - (invoke count:10000000 tsc_interval:1777053420)
[ 466.629838] time_bench: Type:kmem bulk_fallback Per elem: 101 cycles(tsc) 33.965 ns (step:1) - (measurement period time:0.339652351 sec time_interval:339652351) - (invoke count:10000000 tsc_interval:1016989230)
[ 466.933290] time_bench: Type:kmem bulk_quick_reuse Per elem: 90 cycles(tsc) 30.344 ns (step:1) - (measurement period time:0.303444180 sec time_interval:303444180) - (invoke count:10000000 tsc_interval:908575380)
[ 467.250189] time_bench: Type:kmem bulk_fallback Per elem: 94 cycles(tsc) 31.689 ns (step:2) - (measurement period time:0.316896073 sec time_interval:316896073) - (invoke count:10000000 tsc_interval:948853110)
[ 467.430142] time_bench: Type:kmem bulk_quick_reuse Per elem: 53 cycles(tsc) 17.994 ns (step:2) - (measurement period time:0.179940800 sec time_interval:179940800) - (invoke count:10000000 tsc_interval:538779390)
[ 467.780573] time_bench: Type:kmem bulk_fallback Per elem: 104 cycles(tsc) 35.039 ns (step:3) - (measurement period time:0.350394226 sec time_interval:350394226) - (invoke count:9999999 tsc_interval:1049153580)
[ 468.100301] time_bench: Type:kmem bulk_quick_reuse Per elem: 95 cycles(tsc) 31.970 ns (step:3) - (measurement period time:0.319706687 sec time_interval:319706687) - (invoke count:9999999 tsc_interval:957267660)
[ 468.792650] time_bench: Type:kmem bulk_fallback Per elem: 207 cycles(tsc) 69.235 ns (step:4) - (measurement period time:0.692354598 sec time_interval:692354598) - (invoke count:10000000 tsc_interval:2073054750)
[ 469.078816] time_bench: Type:kmem bulk_quick_reuse Per elem: 85 cycles(tsc) 28.614 ns (step:4) - (measurement period time:0.286145162 sec time_interval:286145162) - (invoke count:10000000 tsc_interval:856777710)
[ 469.694558] time_bench: Type:kmem bulk_fallback Per elem: 184 cycles(tsc) 61.573 ns (step:8) - (measurement period time:0.615733224 sec time_interval:615733224) - (invoke count:10000000 tsc_interval:1843634190)
[ 469.917439] time_bench: Type:kmem bulk_quick_reuse Per elem: 66 cycles(tsc) 22.284 ns (step:8) - (measurement period time:0.222848937 sec time_interval:222848937) - (invoke count:10000000 tsc_interval:667255740)
[ 470.586966] time_bench: Type:kmem bulk_fallback Per elem: 200 cycles(tsc) 66.952 ns (step:16) - (measurement period time:0.669526473 sec time_interval:669526473) - (invoke count:10000000 tsc_interval:2004702960)
[ 470.794012] time_bench: Type:kmem bulk_quick_reuse Per elem: 61 cycles(tsc) 20.697 ns (step:16) - (measurement period time:0.206972335 sec time_interval:206972335) - (invoke count:10000000 tsc_interval:619717170)
[ 471.422674] time_bench: Type:kmem bulk_fallback Per elem: 188 cycles(tsc) 62.866 ns (step:30) - (measurement period time:0.628659634 sec time_interval:628659634) - (invoke count:9999990 tsc_interval:1882338990)
[ 471.524193] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.149 ns (step:30) - (measurement period time:0.101497972 sec time_interval:101497972) - (invoke count:9999990 tsc_interval:303905340)
[ 471.829474] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.527 ns (step:32) - (measurement period time:0.305271485 sec time_interval:305271485) - (invoke count:10000000 tsc_interval:914046510)
[ 471.930490] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.099 ns (step:32) - (measurement period time:0.100992877 sec time_interval:100992877) - (invoke count:10000000 tsc_interval:302392890)
[ 472.311211] time_bench: Type:kmem bulk_fallback Per elem: 113 cycles(tsc) 38.072 ns (step:34) - (measurement period time:0.380725777 sec time_interval:380725777) - (invoke count:9999978 tsc_interval:1139972850)
[ 472.429823] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.860 ns (step:34) - (measurement period time:0.118599617 sec time_interval:118599617) - (invoke count:9999978 tsc_interval:355111890)
[ 472.890092] time_bench: Type:kmem bulk_fallback Per elem: 137 cycles(tsc) 46.026 ns (step:48) - (measurement period time:0.460264730 sec time_interval:460264730) - (invoke count:9999984 tsc_interval:1378127970)
[ 472.999481] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.937 ns (step:48) - (measurement period time:0.109371593 sec time_interval:109371593) - (invoke count:9999984 tsc_interval:327480390)
[ 473.344109] time_bench: Type:kmem bulk_fallback Per elem: 103 cycles(tsc) 34.462 ns (step:64) - (measurement period time:0.344629774 sec time_interval:344629774) - (invoke count:10000000 tsc_interval:1031893740)
[ 473.452099] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.794 ns (step:64) - (measurement period time:0.107942846 sec time_interval:107942846) - (invoke count:10000000 tsc_interval:323202390)
[ 474.382899] time_bench: Type:kmem bulk_fallback Per elem: 278 cycles(tsc) 93.080 ns (step:128) - (measurement period time:0.930809025 sec time_interval:930809025) - (invoke count:10000000 tsc_interval:2787037260)
[ 474.729757] time_bench: Type:kmem bulk_quick_reuse Per elem: 103 cycles(tsc) 34.683 ns (step:128) - (measurement period time:0.346831572 sec time_interval:346831572) - (invoke count:10000000 tsc_interval:1038484980)
[ 475.616707] time_bench: Type:kmem bulk_fallback Per elem: 265 cycles(tsc) 88.693 ns (step:158) - (measurement period time:0.886937188 sec time_interval:886937188) - (invoke count:9999978 tsc_interval:2655675660)
[ 475.890425] time_bench: Type:kmem bulk_quick_reuse Per elem: 81 cycles(tsc) 27.369 ns (step:158) - (measurement period time:0.273692416 sec time_interval:273692416) - (invoke count:9999978 tsc_interval:819491040)
[ 476.275144] time_bench: Type:kmem bulk_fallback Per elem: 115 cycles(tsc) 38.471 ns (step:250) - (measurement period time:0.384713160 sec time_interval:384713160) - (invoke count:10000000 tsc_interval:1151911110)
[ 476.424219] time_bench: Type:kmem bulk_quick_reuse Per elem: 44 cycles(tsc) 14.906 ns (step:250) - (measurement period time:0.149068364 sec time_interval:149068364) - (invoke count:10000000 tsc_interval:446341830)
[ 490.306824] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.776 ns (step:0) - (measurement period time:0.077691991 sec time_interval:77691991) - (invoke count:100000000 tsc_interval:232625850)
[ 490.897035] time_bench: Type:kmem fastpath reuse Per elem: 176 cycles(tsc) 59.019 ns (step:0) - (measurement period time:0.590195120 sec time_interval:590195120) - (invoke count:10000000 tsc_interval:1767174930)
[ 491.590675] time_bench: Type:kmem bulk_fallback Per elem: 207 cycles(tsc) 69.362 ns (step:1) - (measurement period time:0.693628128 sec time_interval:693628128) - (invoke count:10000000 tsc_interval:2076877050)
[ 492.339461] time_bench: Type:kmem bulk_quick_reuse Per elem: 224 cycles(tsc) 74.877 ns (step:1) - (measurement period time:0.748777171 sec time_interval:748777171) - (invoke count:10000000 tsc_interval:2242005540)
[ 493.129328] time_bench: Type:kmem bulk_fallback Per elem: 236 cycles(tsc) 78.984 ns (step:2) - (measurement period time:0.789848781 sec time_interval:789848781) - (invoke count:10000000 tsc_interval:2364983220)
[ 493.574670] time_bench: Type:kmem bulk_quick_reuse Per elem: 133 cycles(tsc) 44.530 ns (step:2) - (measurement period time:0.445304096 sec time_interval:445304096) - (invoke count:10000000 tsc_interval:1333339110)
[ 493.887021] time_bench: Type:kmem bulk_fallback Per elem: 93 cycles(tsc) 31.231 ns (step:3) - (measurement period time:0.312316389 sec time_interval:312316389) - (invoke count:9999999 tsc_interval:935143950)
[ 494.029383] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.234 ns (step:3) - (measurement period time:0.142346254 sec time_interval:142346254) - (invoke count:9999999 tsc_interval:426216000)
[ 494.369892] time_bench: Type:kmem bulk_fallback Per elem: 101 cycles(tsc) 34.050 ns (step:4) - (measurement period time:0.340504527 sec time_interval:340504527) - (invoke count:10000000 tsc_interval:1019546130)
[ 494.493217] time_bench: Type:kmem bulk_quick_reuse Per elem: 36 cycles(tsc) 12.329 ns (step:4) - (measurement period time:0.123294475 sec time_interval:123294475) - (invoke count:10000000 tsc_interval:369169800)
[ 494.820003] time_bench: Type:kmem bulk_fallback Per elem: 97 cycles(tsc) 32.678 ns (step:8) - (measurement period time:0.326780876 sec time_interval:326780876) - (invoke count:10000000 tsc_interval:978453960)
[ 494.928831] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.880 ns (step:8) - (measurement period time:0.108808086 sec time_interval:108808086) - (invoke count:10000000 tsc_interval:325794570)
[ 495.684358] time_bench: Type:kmem bulk_fallback Per elem: 226 cycles(tsc) 75.552 ns (step:16) - (measurement period time:0.755527917 sec time_interval:755527917) - (invoke count:10000000 tsc_interval:2262218520)
[ 495.785682] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.130 ns (step:16) - (measurement period time:0.101307607 sec time_interval:101307607) - (invoke count:10000000 tsc_interval:303336720)
[ 496.090994] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.528 ns (step:30) - (measurement period time:0.305280433 sec time_interval:305280433) - (invoke count:9999990 tsc_interval:914077290)
[ 496.341570] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.054 ns (step:30) - (measurement period time:0.250548825 sec time_interval:250548825) - (invoke count:9999990 tsc_interval:750197910)
[ 496.646784] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.518 ns (step:32) - (measurement period time:0.305189218 sec time_interval:305189218) - (invoke count:10000000 tsc_interval:913803540)
[ 496.900311] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.349 ns (step:32) - (measurement period time:0.253499465 sec time_interval:253499465) - (invoke count:10000000 tsc_interval:759033060)
[ 497.778600] time_bench: Type:kmem bulk_fallback Per elem: 262 cycles(tsc) 87.830 ns (step:34) - (measurement period time:0.878298604 sec time_interval:878298604) - (invoke count:9999978 tsc_interval:2629821090)
[ 498.043690] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.506 ns (step:34) - (measurement period time:0.265066374 sec time_interval:265066374) - (invoke count:9999978 tsc_interval:793667400)
[ 498.393912] time_bench: Type:kmem bulk_fallback Per elem: 104 cycles(tsc) 35.021 ns (step:48) - (measurement period time:0.350216735 sec time_interval:350216735) - (invoke count:9999984 tsc_interval:1048626840)
[ 498.504846] time_bench: Type:kmem bulk_quick_reuse Per elem: 33 cycles(tsc) 11.092 ns (step:48) - (measurement period time:0.110924201 sec time_interval:110924201) - (invoke count:9999984 tsc_interval:332131200)
[ 498.878335] time_bench: Type:kmem bulk_fallback Per elem: 111 cycles(tsc) 37.345 ns (step:64) - (measurement period time:0.373454272 sec time_interval:373454272) - (invoke count:10000000 tsc_interval:1118205060)
[ 499.145467] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.710 ns (step:64) - (measurement period time:0.267102714 sec time_interval:267102714) - (invoke count:10000000 tsc_interval:799763910)
[ 499.525255] time_bench: Type:kmem bulk_fallback Per elem: 113 cycles(tsc) 37.971 ns (step:128) - (measurement period time:0.379715035 sec time_interval:379715035) - (invoke count:10000000 tsc_interval:1136951190)
[ 499.852495] time_bench: Type:kmem bulk_quick_reuse Per elem: 97 cycles(tsc) 32.721 ns (step:128) - (measurement period time:0.327218329 sec time_interval:327218329) - (invoke count:10000000 tsc_interval:979763670)
[ 500.238889] time_bench: Type:kmem bulk_fallback Per elem: 115 cycles(tsc) 38.638 ns (step:158) - (measurement period time:0.386388112 sec time_interval:386388112) - (invoke count:9999978 tsc_interval:1156931610)
[ 500.370790] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.189 ns (step:158) - (measurement period time:0.131890805 sec time_interval:131890805) - (invoke count:9999978 tsc_interval:394909920)
[ 500.747241] time_bench: Type:kmem bulk_fallback Per elem: 112 cycles(tsc) 37.645 ns (step:250) - (measurement period time:0.376455749 sec time_interval:376455749) - (invoke count:10000000 tsc_interval:1127192310)
[ 500.897248] time_bench: Type:kmem bulk_quick_reuse Per elem: 44 cycles(tsc) 14.999 ns (step:250) - (measurement period time:0.149997635 sec time_interval:149997635) - (invoke count:10000000 tsc_interval:449125920)
Orig:
[ 81.987064] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.813 ns (step:0) - (measurement period time:0.081397445 sec time_interval:81397445) - (invoke count:100000000 tsc_interval:243727920)
[ 82.595831] time_bench: Type:kmem fastpath reuse Per elem: 178 cycles(tsc) 59.675 ns (step:0) - (measurement period time:0.596752095 sec time_interval:596752095) - (invoke count:10000000 tsc_interval:1786857030)
[ 83.031850] time_bench: Type:kmem bulk_fallback Per elem: 127 cycles(tsc) 42.541 ns (step:1) - (measurement period time:0.425415790 sec time_interval:425415790) - (invoke count:10000000 tsc_interval:1273823670)
[ 83.340838] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.200 ns (step:1) - (measurement period time:0.292006301 sec time_interval:292006301) - (invoke count:10000000 tsc_interval:874355190)
[ 83.630781] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.923 ns (step:2) - (measurement period time:0.279231691 sec time_interval:279231691) - (invoke count:10000000 tsc_interval:836104170)
[ 83.821746] time_bench: Type:kmem bulk_quick_reuse Per elem: 52 cycles(tsc) 17.611 ns (step:2) - (measurement period time:0.176116770 sec time_interval:176116770) - (invoke count:10000000 tsc_interval:527346570)
[ 84.105841] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.184 ns (step:3) - (measurement period time:0.271845630 sec time_interval:271845630) - (invoke count:9999999 tsc_interval:813988260)
[ 84.257733] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.120 ns (step:3) - (measurement period time:0.141208965 sec time_interval:141208965) - (invoke count:9999999 tsc_interval:422821890)
[ 84.578730] time_bench: Type:kmem bulk_fallback Per elem: 92 cycles(tsc) 30.798 ns (step:4) - (measurement period time:0.307982589 sec time_interval:307982589) - (invoke count:10000000 tsc_interval:922193070)
[ 84.894740] time_bench: Type:kmem bulk_quick_reuse Per elem: 91 cycles(tsc) 30.523 ns (step:4) - (measurement period time:0.305231656 sec time_interval:305231656) - (invoke count:10000000 tsc_interval:913955310)
[ 85.596699] time_bench: Type:kmem bulk_fallback Per elem: 206 cycles(tsc) 68.977 ns (step:8) - (measurement period time:0.689779758 sec time_interval:689779758) - (invoke count:10000000 tsc_interval:2065410030)
[ 85.728679] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.641 ns (step:8) - (measurement period time:0.106415387 sec time_interval:106415387) - (invoke count:10000000 tsc_interval:318639630)
[ 86.016723] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.302 ns (step:16) - (measurement period time:0.273021863 sec time_interval:273021863) - (invoke count:10000000 tsc_interval:817509990)
[ 86.137711] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 10.005 ns (step:16) - (measurement period time:0.100053210 sec time_interval:100053210) - (invoke count:10000000 tsc_interval:299589180)
[ 86.420698] time_bench: Type:kmem bulk_fallback Per elem: 79 cycles(tsc) 26.598 ns (step:30) - (measurement period time:0.265984644 sec time_interval:265984644) - (invoke count:9999990 tsc_interval:796437960)
[ 86.534652] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.742 ns (step:30) - (measurement period time:0.097425391 sec time_interval:97425391) - (invoke count:9999990 tsc_interval:291720810)
[ 86.812682] time_bench: Type:kmem bulk_fallback Per elem: 79 cycles(tsc) 26.522 ns (step:32) - (measurement period time:0.265225864 sec time_interval:265225864) - (invoke count:10000000 tsc_interval:794166360)
[ 86.923650] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.729 ns (step:32) - (measurement period time:0.097294552 sec time_interval:97294552) - (invoke count:10000000 tsc_interval:291328800)
[ 87.255647] time_bench: Type:kmem bulk_fallback Per elem: 95 cycles(tsc) 32.050 ns (step:34) - (measurement period time:0.320499429 sec time_interval:320499429) - (invoke count:9999978 tsc_interval:959672160)
[ 87.383687] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.492 ns (step:34) - (measurement period time:0.114921393 sec time_interval:114921393) - (invoke count:9999978 tsc_interval:344109030)
[ 87.724663] time_bench: Type:kmem bulk_fallback Per elem: 96 cycles(tsc) 32.346 ns (step:48) - (measurement period time:0.323463245 sec time_interval:323463245) - (invoke count:9999984 tsc_interval:968546670)
[ 87.847640] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.661 ns (step:48) - (measurement period time:0.106610938 sec time_interval:106610938) - (invoke count:9999984 tsc_interval:319225170)
[ 88.167636] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.678 ns (step:64) - (measurement period time:0.306781428 sec time_interval:306781428) - (invoke count:10000000 tsc_interval:918596670)
[ 88.287645] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.677 ns (step:64) - (measurement period time:0.106773747 sec time_interval:106773747) - (invoke count:10000000 tsc_interval:319712640)
[ 88.634627] time_bench: Type:kmem bulk_fallback Per elem: 100 cycles(tsc) 33.591 ns (step:128) - (measurement period time:0.335914141 sec time_interval:335914141) - (invoke count:10000000 tsc_interval:1005828930)
[ 88.785630] time_bench: Type:kmem bulk_quick_reuse Per elem: 40 cycles(tsc) 13.648 ns (step:128) - (measurement period time:0.136483174 sec time_interval:136483174) - (invoke count:10000000 tsc_interval:408671550)
[ 89.138604] time_bench: Type:kmem bulk_fallback Per elem: 101 cycles(tsc) 33.981 ns (step:158) - (measurement period time:0.339814415 sec time_interval:339814415) - (invoke count:9999978 tsc_interval:1017507030)
[ 89.289633] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.110 ns (step:158) - (measurement period time:0.141101621 sec time_interval:141101621) - (invoke count:9999978 tsc_interval:422500530)
[ 89.650638] time_bench: Type:kmem bulk_fallback Per elem: 104 cycles(tsc) 34.887 ns (step:250) - (measurement period time:0.348876887 sec time_interval:348876887) - (invoke count:10000000 tsc_interval:1044643320)
[ 89.813613] time_bench: Type:kmem bulk_quick_reuse Per elem: 44 cycles(tsc) 14.821 ns (step:250) - (measurement period time:0.148213151 sec time_interval:148213151) - (invoke count:10000000 tsc_interval:443794860)
[ 120.495694] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.777 ns (step:0) - (measurement period time:0.077764814 sec time_interval:77764814) - (invoke count:100000000 tsc_interval:232850730)
[ 121.018849] time_bench: Type:kmem fastpath reuse Per elem: 153 cycles(tsc) 51.274 ns (step:0) - (measurement period time:0.512740018 sec time_interval:512740018) - (invoke count:10000000 tsc_interval:1535297070)
[ 121.326965] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.560 ns (step:1) - (measurement period time:0.305608844 sec time_interval:305608844) - (invoke count:10000000 tsc_interval:915084480)
[ 121.628922] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.218 ns (step:1) - (measurement period time:0.292184439 sec time_interval:292184439) - (invoke count:10000000 tsc_interval:874887840)
[ 122.337817] time_bench: Type:kmem bulk_fallback Per elem: 207 cycles(tsc) 69.361 ns (step:2) - (measurement period time:0.693612284 sec time_interval:693612284) - (invoke count:10000000 tsc_interval:2076883890)
[ 122.520912] time_bench: Type:kmem bulk_quick_reuse Per elem: 53 cycles(tsc) 17.741 ns (step:2) - (measurement period time:0.177417675 sec time_interval:177417675) - (invoke count:10000000 tsc_interval:531240870)
[ 122.872912] time_bench: Type:kmem bulk_fallback Per elem: 102 cycles(tsc) 34.212 ns (step:3) - (measurement period time:0.342120142 sec time_interval:342120142) - (invoke count:9999999 tsc_interval:1024409910)
[ 123.019909] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.084 ns (step:3) - (measurement period time:0.140842225 sec time_interval:140842225) - (invoke count:9999999 tsc_interval:421723650)
[ 123.837965] time_bench: Type:kmem bulk_fallback Per elem: 241 cycles(tsc) 80.516 ns (step:4) - (measurement period time:0.805161046 sec time_interval:805161046) - (invoke count:10000000 tsc_interval:2410894650)
[ 123.973915] time_bench: Type:kmem bulk_quick_reuse Per elem: 37 cycles(tsc) 12.377 ns (step:4) - (measurement period time:0.123773940 sec time_interval:123773940) - (invoke count:10000000 tsc_interval:370615290)
[ 124.273862] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.860 ns (step:8) - (measurement period time:0.288604912 sec time_interval:288604912) - (invoke count:10000000 tsc_interval:864169920)
[ 124.546757] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.420 ns (step:8) - (measurement period time:0.264207028 sec time_interval:264207028) - (invoke count:10000000 tsc_interval:791114430)
[ 125.191730] time_bench: Type:kmem bulk_fallback Per elem: 190 cycles(tsc) 63.456 ns (step:16) - (measurement period time:0.634568513 sec time_interval:634568513) - (invoke count:10000000 tsc_interval:1900088820)
[ 125.296839] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.043 ns (step:16) - (measurement period time:0.100439926 sec time_interval:100439926) - (invoke count:10000000 tsc_interval:300746670)
[ 125.580743] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.347 ns (step:30) - (measurement period time:0.273471271 sec time_interval:273471271) - (invoke count:9999990 tsc_interval:818855040)
[ 125.836734] time_bench: Type:kmem bulk_quick_reuse Per elem: 72 cycles(tsc) 24.372 ns (step:30) - (measurement period time:0.243727806 sec time_interval:243727806) - (invoke count:9999990 tsc_interval:729793590)
[ 126.508883] time_bench: Type:kmem bulk_fallback Per elem: 197 cycles(tsc) 65.900 ns (step:32) - (measurement period time:0.659009779 sec time_interval:659009779) - (invoke count:10000000 tsc_interval:1973273460)
[ 126.612891] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.749 ns (step:32) - (measurement period time:0.097491968 sec time_interval:97491968) - (invoke count:10000000 tsc_interval:291919890)
[ 126.968798] time_bench: Type:kmem bulk_fallback Per elem: 103 cycles(tsc) 34.676 ns (step:34) - (measurement period time:0.346762028 sec time_interval:346762028) - (invoke count:9999978 tsc_interval:1038309510)
[ 127.095700] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.648 ns (step:34) - (measurement period time:0.116483925 sec time_interval:116483925) - (invoke count:9999978 tsc_interval:348787590)
[ 127.974794] time_bench: Type:kmem bulk_fallback Per elem: 259 cycles(tsc) 86.651 ns (step:48) - (measurement period time:0.866514663 sec time_interval:866514663) - (invoke count:9999984 tsc_interval:2594605770)
[ 128.093772] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.426 ns (step:48) - (measurement period time:0.114267827 sec time_interval:114267827) - (invoke count:9999984 tsc_interval:342151620)
[ 128.430665] time_bench: Type:kmem bulk_fallback Per elem: 97 cycles(tsc) 32.514 ns (step:64) - (measurement period time:0.325148101 sec time_interval:325148101) - (invoke count:10000000 tsc_interval:973590990)
[ 128.546857] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.991 ns (step:64) - (measurement period time:0.109916673 sec time_interval:109916673) - (invoke count:10000000 tsc_interval:329123280)
[ 129.431645] time_bench: Type:kmem bulk_fallback Per elem: 261 cycles(tsc) 87.191 ns (step:128) - (measurement period time:0.871911323 sec time_interval:871911323) - (invoke count:10000000 tsc_interval:2610764490)
[ 129.583764] time_bench: Type:kmem bulk_quick_reuse Per elem: 43 cycles(tsc) 14.514 ns (step:128) - (measurement period time:0.145148532 sec time_interval:145148532) - (invoke count:10000000 tsc_interval:434617800)
[ 130.443627] time_bench: Type:kmem bulk_fallback Per elem: 254 cycles(tsc) 84.982 ns (step:158) - (measurement period time:0.849826310 sec time_interval:849826310) - (invoke count:9999978 tsc_interval:2544635760)
[ 130.583738] time_bench: Type:kmem bulk_quick_reuse Per elem: 40 cycles(tsc) 13.399 ns (step:158) - (measurement period time:0.133992977 sec time_interval:133992977) - (invoke count:9999978 tsc_interval:401214210)
[ 130.947634] time_bench: Type:kmem bulk_fallback Per elem: 105 cycles(tsc) 35.206 ns (step:250) - (measurement period time:0.352068766 sec time_interval:352068766) - (invoke count:10000000 tsc_interval:1054199400)
[ 131.268601] time_bench: Type:kmem bulk_quick_reuse Per elem: 93 cycles(tsc) 31.142 ns (step:250) - (measurement period time:0.311429067 sec time_interval:311429067) - (invoke count:10000000 tsc_interval:932511270)
[ 135.584335] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.772 ns (step:0) - (measurement period time:0.077217374 sec time_interval:77217374) - (invoke count:100000000 tsc_interval:231211500)
[ 136.122480] time_bench: Type:kmem fastpath reuse Per elem: 156 cycles(tsc) 52.212 ns (step:0) - (measurement period time:0.522120964 sec time_interval:522120964) - (invoke count:10000000 tsc_interval:1563386670)
[ 136.762465] time_bench: Type:kmem bulk_fallback Per elem: 186 cycles(tsc) 62.301 ns (step:1) - (measurement period time:0.623010984 sec time_interval:623010984) - (invoke count:10000000 tsc_interval:1865481540)
[ 137.248444] time_bench: Type:kmem bulk_quick_reuse Per elem: 142 cycles(tsc) 47.606 ns (step:1) - (measurement period time:0.476063536 sec time_interval:476063536) - (invoke count:10000000 tsc_interval:1425477150)
[ 137.540440] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.282 ns (step:2) - (measurement period time:0.282824344 sec time_interval:282824344) - (invoke count:10000000 tsc_interval:846861210)
[ 137.724456] time_bench: Type:kmem bulk_quick_reuse Per elem: 53 cycles(tsc) 17.830 ns (step:2) - (measurement period time:0.178304559 sec time_interval:178304559) - (invoke count:10000000 tsc_interval:533896980)
[ 138.366442] time_bench: Type:kmem bulk_fallback Per elem: 189 cycles(tsc) 63.289 ns (step:3) - (measurement period time:0.632890657 sec time_interval:632890657) - (invoke count:9999999 tsc_interval:1895064930)
[ 138.682405] time_bench: Type:kmem bulk_quick_reuse Per elem: 91 cycles(tsc) 30.603 ns (step:3) - (measurement period time:0.306034382 sec time_interval:306034382) - (invoke count:9999999 tsc_interval:916357950)
[ 138.997539] time_bench: Type:kmem bulk_fallback Per elem: 90 cycles(tsc) 30.372 ns (step:4) - (measurement period time:0.303723704 sec time_interval:303723704) - (invoke count:10000000 tsc_interval:909440220)
[ 139.131400] time_bench: Type:kmem bulk_quick_reuse Per elem: 37 cycles(tsc) 12.405 ns (step:4) - (measurement period time:0.124058230 sec time_interval:124058230) - (invoke count:10000000 tsc_interval:371467110)
[ 139.430407] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.867 ns (step:8) - (measurement period time:0.288673242 sec time_interval:288673242) - (invoke count:10000000 tsc_interval:864374550)
[ 139.694401] time_bench: Type:kmem bulk_quick_reuse Per elem: 76 cycles(tsc) 25.593 ns (step:8) - (measurement period time:0.255935939 sec time_interval:255935939) - (invoke count:10000000 tsc_interval:766348440)
[ 140.387369] time_bench: Type:kmem bulk_fallback Per elem: 203 cycles(tsc) 68.061 ns (step:16) - (measurement period time:0.680610963 sec time_interval:680610963) - (invoke count:10000000 tsc_interval:2037954090)
[ 140.495385] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.173 ns (step:16) - (measurement period time:0.101737300 sec time_interval:101737300) - (invoke count:10000000 tsc_interval:304631430)
[ 141.101479] time_bench: Type:kmem bulk_fallback Per elem: 177 cycles(tsc) 59.116 ns (step:30) - (measurement period time:0.591165326 sec time_interval:591165326) - (invoke count:9999990 tsc_interval:1770126360)
[ 141.350337] time_bench: Type:kmem bulk_quick_reuse Per elem: 72 cycles(tsc) 24.305 ns (step:30) - (measurement period time:0.243051460 sec time_interval:243051460) - (invoke count:9999990 tsc_interval:727767660)
[ 141.781369] time_bench: Type:kmem bulk_fallback Per elem: 126 cycles(tsc) 42.191 ns (step:32) - (measurement period time:0.421915112 sec time_interval:421915112) - (invoke count:10000000 tsc_interval:1263340320)
[ 142.029348] time_bench: Type:kmem bulk_quick_reuse Per elem: 72 cycles(tsc) 24.208 ns (step:32) - (measurement period time:0.242082250 sec time_interval:242082250) - (invoke count:10000000 tsc_interval:724865610)
[ 142.833301] time_bench: Type:kmem bulk_fallback Per elem: 237 cycles(tsc) 79.313 ns (step:34) - (measurement period time:0.793128746 sec time_interval:793128746) - (invoke count:9999978 tsc_interval:2374865760)
[ 142.957327] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.796 ns (step:34) - (measurement period time:0.117960158 sec time_interval:117960158) - (invoke count:9999978 tsc_interval:353207850)
[ 143.714486] time_bench: Type:kmem bulk_fallback Per elem: 223 cycles(tsc) 74.629 ns (step:48) - (measurement period time:0.746296426 sec time_interval:746296426) - (invoke count:9999984 tsc_interval:2234635890)
[ 143.998413] time_bench: Type:kmem bulk_quick_reuse Per elem: 82 cycles(tsc) 27.476 ns (step:48) - (measurement period time:0.274759868 sec time_interval:274759868) - (invoke count:9999984 tsc_interval:822712920)
[ 144.717341] time_bench: Type:kmem bulk_fallback Per elem: 211 cycles(tsc) 70.598 ns (step:64) - (measurement period time:0.705984861 sec time_interval:705984861) - (invoke count:10000000 tsc_interval:2113930770)
[ 144.838259] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.788 ns (step:64) - (measurement period time:0.107887319 sec time_interval:107887319) - (invoke count:10000000 tsc_interval:323046420)
[ 145.190386] time_bench: Type:kmem bulk_fallback Per elem: 102 cycles(tsc) 34.174 ns (step:128) - (measurement period time:0.341741874 sec time_interval:341741874) - (invoke count:10000000 tsc_interval:1023278130)
[ 145.514275] time_bench: Type:kmem bulk_quick_reuse Per elem: 93 cycles(tsc) 31.128 ns (step:128) - (measurement period time:0.311288149 sec time_interval:311288149) - (invoke count:10000000 tsc_interval:932088960)
[ 146.367413] time_bench: Type:kmem bulk_fallback Per elem: 251 cycles(tsc) 84.015 ns (step:158) - (measurement period time:0.840153692 sec time_interval:840153692) - (invoke count:9999978 tsc_interval:2515672920)
[ 146.523219] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.280 ns (step:158) - (measurement period time:0.142806094 sec time_interval:142806094) - (invoke count:9999978 tsc_interval:427603830)
[ 146.888375] time_bench: Type:kmem bulk_fallback Per elem: 105 cycles(tsc) 35.119 ns (step:250) - (measurement period time:0.351191259 sec time_interval:351191259) - (invoke count:10000000 tsc_interval:1051571610)
[ 147.291226] time_bench: Type:kmem bulk_quick_reuse Per elem: 117 cycles(tsc) 39.200 ns (step:250) - (measurement period time:0.392003176 sec time_interval:392003176) - (invoke count:10000000 tsc_interval:1173774360)
SLAB:
Orig:
[ 80.499545] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.830 ns (step:0) - (measurement period time:0.083085912 sec time_interval:83085912) - (invoke count:100000000 tsc_interval:248781840)
[ 81.099911] time_bench: Type:kmem fastpath reuse Per elem: 174 cycles(tsc) 58.430 ns (step:0) - (measurement period time:0.584308185 sec time_interval:584308185) - (invoke count:10000000 tsc_interval:1749584790)
[ 81.421881] time_bench: Type:kmem bulk_fallback Per elem: 89 cycles(tsc) 30.019 ns (step:1) - (measurement period time:0.300198661 sec time_interval:300198661) - (invoke count:10000000 tsc_interval:898879710)
[ 81.910960] time_bench: Type:kmem bulk_quick_reuse Per elem: 143 cycles(tsc) 47.889 ns (step:1) - (measurement period time:0.478893310 sec time_interval:478893310) - (invoke count:10000000 tsc_interval:1433941530)
[ 82.583917] time_bench: Type:kmem bulk_fallback Per elem: 197 cycles(tsc) 65.813 ns (step:2) - (measurement period time:0.658134429 sec time_interval:658134429) - (invoke count:10000000 tsc_interval:1970640660)
[ 82.751867] time_bench: Type:kmem bulk_quick_reuse Per elem: 45 cycles(tsc) 15.221 ns (step:2) - (measurement period time:0.152212195 sec time_interval:152212195) - (invoke count:10000000 tsc_interval:455766000)
[ 83.047850] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.831 ns (step:3) - (measurement period time:0.278309326 sec time_interval:278309326) - (invoke count:9999999 tsc_interval:833336640)
[ 83.186831] time_bench: Type:kmem bulk_quick_reuse Per elem: 38 cycles(tsc) 12.885 ns (step:3) - (measurement period time:0.128853000 sec time_interval:128853000) - (invoke count:9999999 tsc_interval:385821900)
[ 83.514848] time_bench: Type:kmem bulk_fallback Per elem: 92 cycles(tsc) 30.901 ns (step:4) - (measurement period time:0.309012550 sec time_interval:309012550) - (invoke count:10000000 tsc_interval:925270980)
[ 83.646835] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.711 ns (step:4) - (measurement period time:0.117116655 sec time_interval:117116655) - (invoke count:10000000 tsc_interval:350679900)
[ 83.954817] time_bench: Type:kmem bulk_fallback Per elem: 89 cycles(tsc) 29.739 ns (step:8) - (measurement period time:0.297398266 sec time_interval:297398266) - (invoke count:10000000 tsc_interval:890494290)
[ 84.069826] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.943 ns (step:8) - (measurement period time:0.099437599 sec time_interval:99437599) - (invoke count:10000000 tsc_interval:297743760)
[ 84.361844] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.263 ns (step:16) - (measurement period time:0.282630878 sec time_interval:282630878) - (invoke count:10000000 tsc_interval:846277020)
[ 84.471816] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.643 ns (step:16) - (measurement period time:0.096439729 sec time_interval:96439729) - (invoke count:10000000 tsc_interval:288767550)
[ 84.977793] time_bench: Type:kmem bulk_fallback Per elem: 145 cycles(tsc) 48.452 ns (step:30) - (measurement period time:0.484520609 sec time_interval:484520609) - (invoke count:9999990 tsc_interval:1450791510)
[ 85.222771] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 22.726 ns (step:30) - (measurement period time:0.227266268 sec time_interval:227266268) - (invoke count:9999990 tsc_interval:680498580)
[ 85.814766] time_bench: Type:kmem bulk_fallback Per elem: 173 cycles(tsc) 57.907 ns (step:32) - (measurement period time:0.579072933 sec time_interval:579072933) - (invoke count:10000000 tsc_interval:1733908170)
[ 85.914739] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.385 ns (step:32) - (measurement period time:0.093857661 sec time_interval:93857661) - (invoke count:10000000 tsc_interval:281035770)
[ 86.207764] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.489 ns (step:34) - (measurement period time:0.274891966 sec time_interval:274891966) - (invoke count:9999978 tsc_interval:823104480)
[ 86.452755] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 23.040 ns (step:34) - (measurement period time:0.230401610 sec time_interval:230401610) - (invoke count:9999978 tsc_interval:689886630)
[ 86.736743] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.326 ns (step:48) - (measurement period time:0.273267062 sec time_interval:273267062) - (invoke count:9999984 tsc_interval:818238330)
[ 86.839857] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.506 ns (step:48) - (measurement period time:0.095059470 sec time_interval:95059470) - (invoke count:9999984 tsc_interval:284634690)
[ 87.432947] time_bench: Type:kmem bulk_fallback Per elem: 172 cycles(tsc) 57.565 ns (step:64) - (measurement period time:0.575650143 sec time_interval:575650143) - (invoke count:10000000 tsc_interval:1723659720)
[ 87.536682] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.267 ns (step:64) - (measurement period time:0.092674016 sec time_interval:92674016) - (invoke count:10000000 tsc_interval:277491600)
[ 87.829693] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.082 ns (step:128) - (measurement period time:0.280825239 sec time_interval:280825239) - (invoke count:10000000 tsc_interval:840869820)
[ 87.942860] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.387 ns (step:128) - (measurement period time:0.103871104 sec time_interval:103871104) - (invoke count:10000000 tsc_interval:311019150)
[ 88.242686] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.101 ns (step:158) - (measurement period time:0.281012946 sec time_interval:281012946) - (invoke count:9999978 tsc_interval:841431990)
[ 88.354683] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.852 ns (step:158) - (measurement period time:0.098524040 sec time_interval:98524040) - (invoke count:9999978 tsc_interval:295008030)
[ 88.655671] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.946 ns (step:250) - (measurement period time:0.289463793 sec time_interval:289463793) - (invoke count:10000000 tsc_interval:866736720)
[ 88.776655] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.695 ns (step:250) - (measurement period time:0.106953355 sec time_interval:106953355) - (invoke count:10000000 tsc_interval:320247930)
[ 100.068788] time_bench: Type:for_loop Per elem: 4 cycles(tsc) 1.567 ns (step:0) - (measurement period time:0.156710185 sec time_interval:156710185) - (invoke count:100000000 tsc_interval:469233480)
[ 100.654304] time_bench: Type:kmem fastpath reuse Per elem: 170 cycles(tsc) 56.967 ns (step:0) - (measurement period time:0.569671924 sec time_interval:569671924) - (invoke count:10000000 tsc_interval:1705759620)
[ 101.373300] time_bench: Type:kmem bulk_fallback Per elem: 212 cycles(tsc) 70.812 ns (step:1) - (measurement period time:0.708129741 sec time_interval:708129741) - (invoke count:10000000 tsc_interval:2120342250)
[ 101.840283] time_bench: Type:kmem bulk_quick_reuse Per elem: 136 cycles(tsc) 45.527 ns (step:1) - (measurement period time:0.455275848 sec time_interval:455275848) - (invoke count:10000000 tsc_interval:1363225020)
[ 102.139276] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 29.044 ns (step:2) - (measurement period time:0.290446762 sec time_interval:290446762) - (invoke count:10000000 tsc_interval:869680110)
[ 102.303272] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.383 ns (step:2) - (measurement period time:0.153838537 sec time_interval:153838537) - (invoke count:10000000 tsc_interval:460636140)
[ 103.012346] time_bench: Type:kmem bulk_fallback Per elem: 209 cycles(tsc) 69.979 ns (step:3) - (measurement period time:0.699793666 sec time_interval:699793666) - (invoke count:9999999 tsc_interval:2095381860)
[ 103.148352] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.208 ns (step:3) - (measurement period time:0.132082868 sec time_interval:132082868) - (invoke count:9999999 tsc_interval:395493210)
[ 103.462233] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.467 ns (step:4) - (measurement period time:0.304675759 sec time_interval:304675759) - (invoke count:10000000 tsc_interval:912285930)
[ 103.761428] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.059 ns (step:4) - (measurement period time:0.290597158 sec time_interval:290597158) - (invoke count:10000000 tsc_interval:870129780)
[ 104.501334] time_bench: Type:kmem bulk_fallback Per elem: 218 cycles(tsc) 73.076 ns (step:8) - (measurement period time:0.730767822 sec time_interval:730767822) - (invoke count:10000000 tsc_interval:2188127310)
[ 104.732329] time_bench: Type:kmem bulk_quick_reuse Per elem: 66 cycles(tsc) 22.280 ns (step:8) - (measurement period time:0.222806934 sec time_interval:222806934) - (invoke count:10000000 tsc_interval:667146780)
[ 105.346195] time_bench: Type:kmem bulk_fallback Per elem: 180 cycles(tsc) 60.308 ns (step:16) - (measurement period time:0.603085855 sec time_interval:603085855) - (invoke count:10000000 tsc_interval:1805810910)
[ 105.565213] time_bench: Type:kmem bulk_quick_reuse Per elem: 62 cycles(tsc) 20.731 ns (step:16) - (measurement period time:0.207317878 sec time_interval:207317878) - (invoke count:10000000 tsc_interval:620768190)
[ 106.154163] time_bench: Type:kmem bulk_fallback Per elem: 173 cycles(tsc) 57.884 ns (step:30) - (measurement period time:0.578841035 sec time_interval:578841035) - (invoke count:9999990 tsc_interval:1733213910)
[ 106.450218] time_bench: Type:kmem bulk_quick_reuse Per elem: 85 cycles(tsc) 28.455 ns (step:30) - (measurement period time:0.284558769 sec time_interval:284558769) - (invoke count:9999990 tsc_interval:852048780)
[ 107.137140] time_bench: Type:kmem bulk_fallback Per elem: 199 cycles(tsc) 66.729 ns (step:32) - (measurement period time:0.667298185 sec time_interval:667298185) - (invoke count:10000000 tsc_interval:1998081120)
[ 107.244232] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.655 ns (step:32) - (measurement period time:0.096558958 sec time_interval:96558958) - (invoke count:10000000 tsc_interval:289124430)
[ 107.528225] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.584 ns (step:34) - (measurement period time:0.275841028 sec time_interval:275841028) - (invoke count:9999978 tsc_interval:825940800)
[ 107.628207] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.182 ns (step:34) - (measurement period time:0.091822659 sec time_interval:91822659) - (invoke count:9999978 tsc_interval:274942830)
[ 107.913114] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.639 ns (step:48) - (measurement period time:0.276397658 sec time_interval:276397658) - (invoke count:9999984 tsc_interval:827612400)
[ 108.013118] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.281 ns (step:48) - (measurement period time:0.092811773 sec time_interval:92811773) - (invoke count:9999984 tsc_interval:277904550)
[ 108.293222] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.413 ns (step:64) - (measurement period time:0.274134107 sec time_interval:274134107) - (invoke count:10000000 tsc_interval:820835190)
[ 108.394122] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.252 ns (step:64) - (measurement period time:0.092524305 sec time_interval:92524305) - (invoke count:10000000 tsc_interval:277043580)
[ 109.015115] time_bench: Type:kmem bulk_fallback Per elem: 183 cycles(tsc) 61.171 ns (step:128) - (measurement period time:0.611713784 sec time_interval:611713784) - (invoke count:10000000 tsc_interval:1831645590)
[ 109.282175] time_bench: Type:kmem bulk_quick_reuse Per elem: 76 cycles(tsc) 25.538 ns (step:128) - (measurement period time:0.255382498 sec time_interval:255382498) - (invoke count:10000000 tsc_interval:764687130)
[ 109.898178] time_bench: Type:kmem bulk_fallback Per elem: 181 cycles(tsc) 60.732 ns (step:158) - (measurement period time:0.607324486 sec time_interval:607324486) - (invoke count:9999978 tsc_interval:1818501990)
[ 110.111052] time_bench: Type:kmem bulk_quick_reuse Per elem: 60 cycles(tsc) 20.241 ns (step:158) - (measurement period time:0.202414120 sec time_interval:202414120) - (invoke count:9999978 tsc_interval:606085230)
[ 110.715034] time_bench: Type:kmem bulk_fallback Per elem: 178 cycles(tsc) 59.483 ns (step:250) - (measurement period time:0.594833299 sec time_interval:594833299) - (invoke count:10000000 tsc_interval:1781100600)
[ 110.974129] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.167 ns (step:250) - (measurement period time:0.251679547 sec time_interval:251679547) - (invoke count:10000000 tsc_interval:753599310)
[ 111.856730] time_bench: Type:for_loop Per elem: 4 cycles(tsc) 1.349 ns (step:0) - (measurement period time:0.134993630 sec time_interval:134993630) - (invoke count:100000000 tsc_interval:404208090)
[ 112.407098] time_bench: Type:kmem fastpath reuse Per elem: 159 cycles(tsc) 53.400 ns (step:0) - (measurement period time:0.534001917 sec time_interval:534001917) - (invoke count:10000000 tsc_interval:1598953680)
[ 113.150981] time_bench: Type:kmem bulk_fallback Per elem: 216 cycles(tsc) 72.396 ns (step:1) - (measurement period time:0.723960939 sec time_interval:723960939) - (invoke count:10000000 tsc_interval:2167744650)
[ 113.381971] time_bench: Type:kmem bulk_quick_reuse Per elem: 67 cycles(tsc) 22.501 ns (step:1) - (measurement period time:0.225017504 sec time_interval:225017504) - (invoke count:10000000 tsc_interval:673765620)
[ 113.681963] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.967 ns (step:2) - (measurement period time:0.289671345 sec time_interval:289671345) - (invoke count:10000000 tsc_interval:867358230)
[ 113.843955] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.643 ns (step:2) - (measurement period time:0.156437917 sec time_interval:156437917) - (invoke count:10000000 tsc_interval:468418740)
[ 114.140953] time_bench: Type:kmem bulk_fallback Per elem: 85 cycles(tsc) 28.414 ns (step:3) - (measurement period time:0.284148848 sec time_interval:284148848) - (invoke count:9999999 tsc_interval:850821930)
[ 114.279933] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.207 ns (step:3) - (measurement period time:0.132073229 sec time_interval:132073229) - (invoke count:9999999 tsc_interval:395463870)
[ 114.609120] time_bench: Type:kmem bulk_fallback Per elem: 93 cycles(tsc) 31.197 ns (step:4) - (measurement period time:0.311972955 sec time_interval:311972955) - (invoke count:10000000 tsc_interval:934136040)
[ 114.909950] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.326 ns (step:4) - (measurement period time:0.293267093 sec time_interval:293267093) - (invoke count:10000000 tsc_interval:878124330)
[ 115.622058] time_bench: Type:kmem bulk_fallback Per elem: 209 cycles(tsc) 70.083 ns (step:8) - (measurement period time:0.700833456 sec time_interval:700833456) - (invoke count:10000000 tsc_interval:2098495740)
[ 115.729918] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.072 ns (step:8) - (measurement period time:0.100729060 sec time_interval:100729060) - (invoke count:10000000 tsc_interval:301610850)
[ 116.445890] time_bench: Type:kmem bulk_fallback Per elem: 211 cycles(tsc) 70.512 ns (step:16) - (measurement period time:0.705126903 sec time_interval:705126903) - (invoke count:10000000 tsc_interval:2111350800)
[ 116.597986] time_bench: Type:kmem bulk_quick_reuse Per elem: 43 cycles(tsc) 14.451 ns (step:16) - (measurement period time:0.144517256 sec time_interval:144517256) - (invoke count:10000000 tsc_interval:432725340)
[ 117.293842] time_bench: Type:kmem bulk_fallback Per elem: 205 cycles(tsc) 68.660 ns (step:30) - (measurement period time:0.686602607 sec time_interval:686602607) - (invoke count:9999990 tsc_interval:2055883860)
[ 117.513834] time_bench: Type:kmem bulk_quick_reuse Per elem: 65 cycles(tsc) 21.724 ns (step:30) - (measurement period time:0.217241306 sec time_interval:217241306) - (invoke count:9999990 tsc_interval:650481120)
[ 118.157816] time_bench: Type:kmem bulk_fallback Per elem: 189 cycles(tsc) 63.344 ns (step:32) - (measurement period time:0.633443044 sec time_interval:633443044) - (invoke count:10000000 tsc_interval:1896708780)
[ 118.380992] time_bench: Type:kmem bulk_quick_reuse Per elem: 64 cycles(tsc) 21.381 ns (step:32) - (measurement period time:0.213815392 sec time_interval:213815392) - (invoke count:10000000 tsc_interval:640223670)
[ 118.981808] time_bench: Type:kmem bulk_fallback Per elem: 176 cycles(tsc) 58.885 ns (step:34) - (measurement period time:0.588855917 sec time_interval:588855917) - (invoke count:9999978 tsc_interval:1763201640)
[ 119.078787] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.191 ns (step:34) - (measurement period time:0.091919103 sec time_interval:91919103) - (invoke count:9999978 tsc_interval:275231340)
[ 119.368789] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.533 ns (step:48) - (measurement period time:0.275334132 sec time_interval:275334132) - (invoke count:9999984 tsc_interval:824428110)
[ 119.471780] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.519 ns (step:48) - (measurement period time:0.095195091 sec time_interval:95195091) - (invoke count:9999984 tsc_interval:285040080)
[ 119.775775] time_bench: Type:kmem bulk_fallback Per elem: 87 cycles(tsc) 29.149 ns (step:64) - (measurement period time:0.291498274 sec time_interval:291498274) - (invoke count:10000000 tsc_interval:872828640)
[ 119.896771] time_bench: Type:kmem bulk_quick_reuse Per elem: 33 cycles(tsc) 11.330 ns (step:64) - (measurement period time:0.113304207 sec time_interval:113304207) - (invoke count:10000000 tsc_interval:339264000)
[ 120.199773] time_bench: Type:kmem bulk_fallback Per elem: 87 cycles(tsc) 29.289 ns (step:128) - (measurement period time:0.292891157 sec time_interval:292891157) - (invoke count:10000000 tsc_interval:876999360)
[ 120.320757] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.476 ns (step:128) - (measurement period time:0.114763286 sec time_interval:114763286) - (invoke count:10000000 tsc_interval:343632900)
[ 120.976762] time_bench: Type:kmem bulk_fallback Per elem: 192 cycles(tsc) 64.320 ns (step:158) - (measurement period time:0.643207519 sec time_interval:643207519) - (invoke count:9999978 tsc_interval:1925946840)
[ 121.231790] time_bench: Type:kmem bulk_quick_reuse Per elem: 73 cycles(tsc) 24.705 ns (step:158) - (measurement period time:0.247055281 sec time_interval:247055281) - (invoke count:9999978 tsc_interval:739752480)
[ 121.875817] time_bench: Type:kmem bulk_fallback Per elem: 189 cycles(tsc) 63.224 ns (step:250) - (measurement period time:0.632244442 sec time_interval:632244442) - (invoke count:10000000 tsc_interval:1893119520)
[ 122.148737] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.410 ns (step:250) - (measurement period time:0.264101742 sec time_interval:264101742) - (invoke count:10000000 tsc_interval:790794030)
Patched:
[ 654.054203] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.776 ns (step:0) - (measurement period time:0.077664118 sec time_interval:77664118) - (invoke count:100000000 tsc_interval:232545750)
[ 654.592857] time_bench: Type:kmem fastpath reuse Per elem: 161 cycles(tsc) 53.860 ns (step:0) - (measurement period time:0.538607021 sec time_interval:538607021) - (invoke count:10000000 tsc_interval:1612734660)
[ 655.248550] time_bench: Type:kmem bulk_fallback Per elem: 196 cycles(tsc) 65.568 ns (step:1) - (measurement period time:0.655680061 sec time_interval:655680061) - (invoke count:10000000 tsc_interval:1963282620)
[ 655.475563] time_bench: Type:kmem bulk_quick_reuse Per elem: 67 cycles(tsc) 22.697 ns (step:1) - (measurement period time:0.226975586 sec time_interval:226975586) - (invoke count:10000000 tsc_interval:679625070)
[ 655.757615] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.204 ns (step:2) - (measurement period time:0.282047104 sec time_interval:282047104) - (invoke count:10000000 tsc_interval:844524090)
[ 655.943657] time_bench: Type:kmem bulk_quick_reuse Per elem: 55 cycles(tsc) 18.599 ns (step:2) - (measurement period time:0.185992389 sec time_interval:185992389) - (invoke count:10000000 tsc_interval:556910100)
[ 656.221528] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.783 ns (step:3) - (measurement period time:0.277833288 sec time_interval:277833288) - (invoke count:9999999 tsc_interval:831906840)
[ 656.535062] time_bench: Type:kmem bulk_quick_reuse Per elem: 93 cycles(tsc) 31.351 ns (step:3) - (measurement period time:0.313512217 sec time_interval:313512217) - (invoke count:9999999 tsc_interval:938739120)
[ 656.843267] time_bench: Type:kmem bulk_fallback Per elem: 92 cycles(tsc) 30.818 ns (step:4) - (measurement period time:0.308185034 sec time_interval:308185034) - (invoke count:10000000 tsc_interval:922788240)
[ 656.961808] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.850 ns (step:4) - (measurement period time:0.118503561 sec time_interval:118503561) - (invoke count:10000000 tsc_interval:354830820)
[ 657.691366] time_bench: Type:kmem bulk_fallback Per elem: 218 cycles(tsc) 72.954 ns (step:8) - (measurement period time:0.729541418 sec time_interval:729541418) - (invoke count:10000000 tsc_interval:2184443100)
[ 657.792001] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.060 ns (step:8) - (measurement period time:0.100604744 sec time_interval:100604744) - (invoke count:10000000 tsc_interval:301236990)
[ 658.070712] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.868 ns (step:16) - (measurement period time:0.278687720 sec time_interval:278687720) - (invoke count:10000000 tsc_interval:834465960)
[ 658.169621] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.887 ns (step:16) - (measurement period time:0.098871033 sec time_interval:98871033) - (invoke count:10000000 tsc_interval:296045940)
[ 658.846891] time_bench: Type:kmem bulk_fallback Per elem: 202 cycles(tsc) 67.726 ns (step:30) - (measurement period time:0.677260248 sec time_interval:677260248) - (invoke count:9999990 tsc_interval:2027899590)
[ 658.940547] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.354 ns (step:30) - (measurement period time:0.093547668 sec time_interval:93547668) - (invoke count:9999990 tsc_interval:280105560)
[ 659.214131] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.356 ns (step:32) - (measurement period time:0.273564878 sec time_interval:273564878) - (invoke count:10000000 tsc_interval:819126750)
[ 659.307010] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.286 ns (step:32) - (measurement period time:0.092862249 sec time_interval:92862249) - (invoke count:10000000 tsc_interval:278053470)
[ 659.577675] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.065 ns (step:34) - (measurement period time:0.270657877 sec time_interval:270657877) - (invoke count:9999978 tsc_interval:810422340)
[ 659.670155] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.246 ns (step:34) - (measurement period time:0.092468447 sec time_interval:92468447) - (invoke count:9999978 tsc_interval:276874410)
[ 659.941498] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.129 ns (step:48) - (measurement period time:0.271292799 sec time_interval:271292799) - (invoke count:9999984 tsc_interval:812323620)
[ 660.034358] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.284 ns (step:48) - (measurement period time:0.092846689 sec time_interval:92846689) - (invoke count:9999984 tsc_interval:278007390)
[ 660.305652] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.125 ns (step:64) - (measurement period time:0.271257793 sec time_interval:271257793) - (invoke count:10000000 tsc_interval:812218680)
[ 660.535235] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 22.955 ns (step:64) - (measurement period time:0.229550122 sec time_interval:229550122) - (invoke count:10000000 tsc_interval:687333360)
[ 660.814888] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.964 ns (step:128) - (measurement period time:0.279643666 sec time_interval:279643666) - (invoke count:10000000 tsc_interval:837328200)
[ 660.915969] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.104 ns (step:128) - (measurement period time:0.101047589 sec time_interval:101047589) - (invoke count:10000000 tsc_interval:302562990)
[ 661.275325] time_bench: Type:kmem bulk_fallback Per elem: 107 cycles(tsc) 35.933 ns (step:158) - (measurement period time:0.359338210 sec time_interval:359338210) - (invoke count:9999978 tsc_interval:1075954290)
[ 661.375091] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.975 ns (step:158) - (measurement period time:0.099750172 sec time_interval:99750172) - (invoke count:9999978 tsc_interval:298678200)
[ 661.655844] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.074 ns (step:250) - (measurement period time:0.280746521 sec time_interval:280746521) - (invoke count:10000000 tsc_interval:840630900)
[ 661.762658] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.680 ns (step:250) - (measurement period time:0.106802018 sec time_interval:106802018) - (invoke count:10000000 tsc_interval:319793460)
[ 663.188701] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.772 ns (step:0) - (measurement period time:0.077219119 sec time_interval:77219119) - (invoke count:100000000 tsc_interval:231214350)
[ 663.723737] time_bench: Type:kmem fastpath reuse Per elem: 160 cycles(tsc) 53.501 ns (step:0) - (measurement period time:0.535016285 sec time_interval:535016285) - (invoke count:10000000 tsc_interval:1601983200)
[ 664.022069] time_bench: Type:kmem bulk_fallback Per elem: 89 cycles(tsc) 29.828 ns (step:1) - (measurement period time:0.298280101 sec time_interval:298280101) - (invoke count:10000000 tsc_interval:893130450)
[ 664.248849] time_bench: Type:kmem bulk_quick_reuse Per elem: 67 cycles(tsc) 22.677 ns (step:1) - (measurement period time:0.226775284 sec time_interval:226775284) - (invoke count:10000000 tsc_interval:679026090)
[ 664.530649] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.179 ns (step:2) - (measurement period time:0.281793671 sec time_interval:281793671) - (invoke count:10000000 tsc_interval:843766020)
[ 664.686627] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.593 ns (step:2) - (measurement period time:0.155939154 sec time_interval:155939154) - (invoke count:10000000 tsc_interval:466923720)
[ 665.370321] time_bench: Type:kmem bulk_fallback Per elem: 204 cycles(tsc) 68.367 ns (step:3) - (measurement period time:0.683678844 sec time_interval:683678844) - (invoke count:9999999 tsc_interval:2047118220)
[ 665.685507] time_bench: Type:kmem bulk_quick_reuse Per elem: 94 cycles(tsc) 31.513 ns (step:3) - (measurement period time:0.315139143 sec time_interval:315139143) - (invoke count:9999999 tsc_interval:943611060)
[ 666.448847] time_bench: Type:kmem bulk_fallback Per elem: 228 cycles(tsc) 76.331 ns (step:4) - (measurement period time:0.763310680 sec time_interval:763310680) - (invoke count:10000000 tsc_interval:2285557860)
[ 666.745314] time_bench: Type:kmem bulk_quick_reuse Per elem: 88 cycles(tsc) 29.643 ns (step:4) - (measurement period time:0.296436791 sec time_interval:296436791) - (invoke count:10000000 tsc_interval:887610960)
[ 667.041829] time_bench: Type:kmem bulk_fallback Per elem: 88 cycles(tsc) 29.650 ns (step:8) - (measurement period time:0.296505592 sec time_interval:296505592) - (invoke count:10000000 tsc_interval:887817120)
[ 667.142484] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.064 ns (step:8) - (measurement period time:0.100642315 sec time_interval:100642315) - (invoke count:10000000 tsc_interval:301350000)
[ 667.420593] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.810 ns (step:16) - (measurement period time:0.278104977 sec time_interval:278104977) - (invoke count:10000000 tsc_interval:832721010)
[ 667.519271] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.866 ns (step:16) - (measurement period time:0.098662815 sec time_interval:98662815) - (invoke count:10000000 tsc_interval:295422450)
[ 667.792475] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.315 ns (step:30) - (measurement period time:0.273152701 sec time_interval:273152701) - (invoke count:9999990 tsc_interval:817892820)
[ 668.023804] time_bench: Type:kmem bulk_quick_reuse Per elem: 69 cycles(tsc) 23.130 ns (step:30) - (measurement period time:0.231303811 sec time_interval:231303811) - (invoke count:9999990 tsc_interval:692584950)
[ 668.696907] time_bench: Type:kmem bulk_fallback Per elem: 201 cycles(tsc) 67.306 ns (step:32) - (measurement period time:0.673067682 sec time_interval:673067682) - (invoke count:10000000 tsc_interval:2015345790)
[ 668.889019] time_bench: Type:kmem bulk_quick_reuse Per elem: 57 cycles(tsc) 19.208 ns (step:32) - (measurement period time:0.192088279 sec time_interval:192088279) - (invoke count:10000000 tsc_interval:575162820)
[ 669.342870] time_bench: Type:kmem bulk_fallback Per elem: 135 cycles(tsc) 45.383 ns (step:34) - (measurement period time:0.453831353 sec time_interval:453831353) - (invoke count:9999978 tsc_interval:1358892420)
[ 669.436107] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.322 ns (step:34) - (measurement period time:0.093220843 sec time_interval:93220843) - (invoke count:9999978 tsc_interval:279126840)
[ 669.707772] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.165 ns (step:48) - (measurement period time:0.271654970 sec time_interval:271654970) - (invoke count:9999984 tsc_interval:813407310)
[ 669.800509] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.268 ns (step:48) - (measurement period time:0.092683978 sec time_interval:92683978) - (invoke count:9999984 tsc_interval:277520190)
[ 670.068757] time_bench: Type:kmem bulk_fallback Per elem: 80 cycles(tsc) 26.823 ns (step:64) - (measurement period time:0.268231313 sec time_interval:268231313) - (invoke count:10000000 tsc_interval:803156580)
[ 670.297078] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 22.829 ns (step:64) - (measurement period time:0.228295958 sec time_interval:228295958) - (invoke count:10000000 tsc_interval:683578080)
[ 670.573819] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.673 ns (step:128) - (measurement period time:0.276731254 sec time_interval:276731254) - (invoke count:10000000 tsc_interval:828607050)
[ 670.676864] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.300 ns (step:128) - (measurement period time:0.103002111 sec time_interval:103002111) - (invoke count:10000000 tsc_interval:308415540)
[ 671.318177] time_bench: Type:kmem bulk_fallback Per elem: 192 cycles(tsc) 64.130 ns (step:158) - (measurement period time:0.641303389 sec time_interval:641303389) - (invoke count:9999978 tsc_interval:1920234600)
[ 671.417083] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.889 ns (step:158) - (measurement period time:0.098890269 sec time_interval:98890269) - (invoke count:9999978 tsc_interval:296103210)
[ 671.700461] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.334 ns (step:250) - (measurement period time:0.283346426 sec time_interval:283346426) - (invoke count:10000000 tsc_interval:848415660)
[ 671.965515] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.502 ns (step:250) - (measurement period time:0.265021064 sec time_interval:265021064) - (invoke count:10000000 tsc_interval:793543500)
[ 686.749446] time_bench: Type:for_loop Per elem: 1 cycles(tsc) 0.660 ns (step:0) - (measurement period time:0.066028480 sec time_interval:66028480) - (invoke count:100000000 tsc_interval:197707140)
[ 687.296902] time_bench: Type:kmem fastpath reuse Per elem: 163 cycles(tsc) 54.742 ns (step:0) - (measurement period time:0.547423736 sec time_interval:547423736) - (invoke count:10000000 tsc_interval:1639141260)
[ 687.910620] time_bench: Type:kmem bulk_fallback Per elem: 183 cycles(tsc) 61.369 ns (step:1) - (measurement period time:0.613692564 sec time_interval:613692564) - (invoke count:10000000 tsc_interval:1837568160)
[ 688.381090] time_bench: Type:kmem bulk_quick_reuse Per elem: 140 cycles(tsc) 47.045 ns (step:1) - (measurement period time:0.470452576 sec time_interval:470452576) - (invoke count:10000000 tsc_interval:1408667550)
[ 688.662045] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.094 ns (step:2) - (measurement period time:0.280943997 sec time_interval:280943997) - (invoke count:10000000 tsc_interval:841225230)
[ 688.817464] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.540 ns (step:2) - (measurement period time:0.155409002 sec time_interval:155409002) - (invoke count:10000000 tsc_interval:465337980)
[ 689.094749] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.723 ns (step:3) - (measurement period time:0.277235751 sec time_interval:277235751) - (invoke count:9999999 tsc_interval:830122170)
[ 689.225706] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.091 ns (step:3) - (measurement period time:0.130919113 sec time_interval:130919113) - (invoke count:9999999 tsc_interval:392008440)
[ 689.988861] time_bench: Type:kmem bulk_fallback Per elem: 228 cycles(tsc) 76.314 ns (step:4) - (measurement period time:0.763146670 sec time_interval:763146670) - (invoke count:10000000 tsc_interval:2285076870)
[ 690.274210] time_bench: Type:kmem bulk_quick_reuse Per elem: 85 cycles(tsc) 28.532 ns (step:4) - (measurement period time:0.285320525 sec time_interval:285320525) - (invoke count:10000000 tsc_interval:854329500)
[ 690.862234] time_bench: Type:kmem bulk_fallback Per elem: 176 cycles(tsc) 58.799 ns (step:8) - (measurement period time:0.587998540 sec time_interval:587998540) - (invoke count:10000000 tsc_interval:1760633010)
[ 690.964020] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.171 ns (step:8) - (measurement period time:0.101718599 sec time_interval:101718599) - (invoke count:10000000 tsc_interval:304573500)
[ 691.245251] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.122 ns (step:16) - (measurement period time:0.281223369 sec time_interval:281223369) - (invoke count:10000000 tsc_interval:842060850)
[ 691.341256] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.599 ns (step:16) - (measurement period time:0.095990014 sec time_interval:95990014) - (invoke count:10000000 tsc_interval:287420100)
[ 691.616379] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.511 ns (step:30) - (measurement period time:0.275116534 sec time_interval:275116534) - (invoke count:9999990 tsc_interval:823776390)
[ 691.710275] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.388 ns (step:30) - (measurement period time:0.093884613 sec time_interval:93884613) - (invoke count:9999990 tsc_interval:281115990)
[ 691.982082] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.180 ns (step:32) - (measurement period time:0.271800767 sec time_interval:271800767) - (invoke count:10000000 tsc_interval:813847530)
[ 692.077384] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.526 ns (step:32) - (measurement period time:0.095266005 sec time_interval:95266005) - (invoke count:10000000 tsc_interval:285252780)
[ 692.348422] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.102 ns (step:34) - (measurement period time:0.271026511 sec time_interval:271026511) - (invoke count:9999978 tsc_interval:811529490)
[ 692.440805] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.236 ns (step:34) - (measurement period time:0.092368535 sec time_interval:92368535) - (invoke count:9999978 tsc_interval:276576810)
[ 692.712439] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.162 ns (step:48) - (measurement period time:0.271619761 sec time_interval:271619761) - (invoke count:9999984 tsc_interval:813305970)
[ 692.945558] time_bench: Type:kmem bulk_quick_reuse Per elem: 69 cycles(tsc) 23.309 ns (step:48) - (measurement period time:0.233091977 sec time_interval:233091977) - (invoke count:9999984 tsc_interval:697942470)
[ 693.234591] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.902 ns (step:64) - (measurement period time:0.289021416 sec time_interval:289021416) - (invoke count:10000000 tsc_interval:865411350)
[ 693.326142] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.153 ns (step:64) - (measurement period time:0.091539475 sec time_interval:91539475) - (invoke count:10000000 tsc_interval:274094220)
[ 693.615858] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.970 ns (step:128) - (measurement period time:0.289709207 sec time_interval:289709207) - (invoke count:10000000 tsc_interval:867470400)
[ 693.717321] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.145 ns (step:128) - (measurement period time:0.101451019 sec time_interval:101451019) - (invoke count:10000000 tsc_interval:303772410)
[ 694.000375] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.304 ns (step:158) - (measurement period time:0.283047625 sec time_interval:283047625) - (invoke count:9999978 tsc_interval:847523850)
[ 694.108588] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.816 ns (step:158) - (measurement period time:0.108168257 sec time_interval:108168257) - (invoke count:9999978 tsc_interval:323885820)
[ 694.392070] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.344 ns (step:250) - (measurement period time:0.283447055 sec time_interval:283447055) - (invoke count:10000000 tsc_interval:848719800)
[ 694.655226] time_bench: Type:kmem bulk_quick_reuse Per elem: 78 cycles(tsc) 26.312 ns (step:250) - (measurement period time:0.263123465 sec time_interval:263123465) - (invoke count:10000000 tsc_interval:787864230)
On Thu, 18 Jun 2020 10:43:44 +0200
Jesper Dangaard Brouer <[email protected]> wrote:
> On Wed, 17 Jun 2020 18:29:28 -0700
> Roman Gushchin <[email protected]> wrote:
>
> > On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > > On 6/17/20 5:32 AM, Roman Gushchin wrote:
> > > > On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> > > >> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> > > >> >
> > > >> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > > >> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > > >> > > >
> > > >> [...]
> > > >> > >
> > > >> > > Have you performed any [perf] testing on SLAB with this patchset?
> > > >> >
> > > >> > The accounting part is the same for SLAB and SLUB, so there should be no
> > > >> > significant difference. I've checked that it compiles, boots and passes
> > > >> > kselftests. And that memory savings are there.
> > > >> >
> > > >>
> > > >> What about performance? Also you mentioned that sharing kmem-cache
> > > >> between accounted and non-accounted can have additional overhead. Any
> > > >> difference between SLAB and SLUB for such a case?
> > > >
> > > > Not really.
> > > >
> > > > Sharing a single set of caches adds some overhead to root- and non-accounted
> > > > allocations, which is something I've tried hard to avoid in my original version.
> > > > But I have to admit, it allows to simplify and remove a lot of code, and here
> > > > it's hard to argue with Johanness, who pushed on this design.
> > > >
> > > > With performance testing it's not that easy, because it's not obvious what
> > > > we wanna test. Obviously, per-object accounting is more expensive, and
> > > > measuring something like 1000000 allocations and deallocations in a line from
> > > > a single kmem_cache will show a regression. But in the real world the relative
> > > > cost of allocations is usually low, and we can get some benefits from a smaller
> > > > working set and from having shared kmem_cache objects cache hot.
> > > > Not speaking about some extra memory and the fragmentation reduction.
> > > >
> > > > We've done an extensive testing of the original version in Facebook production,
> > > > and we haven't noticed any regressions so far. But I have to admit, we were
> > > > using an original version with two sets of kmem_caches.
> > > >
> > > > If you have any specific tests in mind, I can definitely run them. Or if you
> > > > can help with the performance evaluation, I'll appreciate it a lot.
> > >
> > > Jesper provided some pointers here [1], it would be really great if you could
> > > run at least those microbenchmarks. With mmtests it's the major question of
> > > which subset/profiles to run, maybe the referenced commits provide some hints,
> > > or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
> > >
> > > [1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
> >
> > Oh, Jesper, I'm really sorry, somehow I missed your mail.
> > Thank you, Vlastimil, for pointing at it.
> >
> > I've got some results (slab_bulk_test01), but honestly I fail to interpret them.
> >
> > I ran original vs patched with SLUB and SLAB, each test several times and picked
> > 3 which looked most consistently. But it still looks very noisy.
> >
> > I ran them on my desktop (8-core Ryzen 1700, 16 GB RAM, Fedora 32),
> > it's 5.8-rc1 + slab controller v6 vs 5.8-rc1 (default config from Fedora 32).
>
> What about running these tests on the server level hardware, that you
> intent to run this on?
To give you an idea of the performance difference I ran the same test
on a Broadwell Intel(R) Xeon(R) CPU E5-1650 v4 @ 3.60GHz.
The SLUB fastpath:
Type:kmem fastpath reuse Per elem: 60 cycles(tsc) 16.822 ns
> >
> > How should I interpret this data?
>
> First of all these SLUB+SLAB microbenchmarks use object size 256 bytes,
> because network stack alloc object of this size for SKBs/sk_buff (due
> to cache-align as used size is 224 bytes). Checked SLUB: Each slab use
> 2 pages (8192 bytes) and contain 32 object of size 256 (256*32=8192).
>
> The SLUB allocator have a per-CPU slab which speedup fast-reuse, in this
> case up-to 32 objects. For SLUB the "fastpath reuse" test this behaviour,
> and it serves as a baseline for optimal 1-object performance (where my bulk
> API tries to beat that, which is possible even for 1-object due to knowing
> bulk API cannot be used from IRQ context).
>
> SLUB fastpath: 3 measurements reporting cycles(tsc)
> - SLUB-patched : fastpath reuse: 184 - 177 - 176 cycles(tsc)
> - SLUB-original: fastpath reuse: 178 - 153 - 156 cycles(tsc)
>
For your SLAB results:
SLAB fastpath: 3 measurements reporting cycles(tsc)
- SLAB-patched : 161 - 160 - 163 cycles(tsc)
- SLAB-original: 174 - 170 - 159 cycles(tsc)
I find it strange that SLAB is slightly better than SLUB (in many
measurements), because SLUB should have an advantage on this fast-path
quick reuse due to the per-CPU slabs. Maybe this is also related to
the CPU arch you are using?
> There are some stability concerns as you mention, but it seems pretty
> consistently that patched version is slower. If you compile with
> no-PREEMPT you can likely get more stable results (and remove a slight
> overhead for SLUB fastpath).
>
> The microbenchmark also measures the bulk-API, which is AFAIK only used
> by network stack (and io_uring). I guess you shouldn't focus too much
> on these bulk measurements. When bulk-API cross this objects per slab
> threshold, or is unlucky is it use two per-CPU slab, then the
> measurements can fluctuate a bit.
>
> Your numbers for SLUB bulk-API:
>
> SLUB-patched - bulk-API
> - SLUB-patched : bulk_quick_reuse objects=1 : 187 - 90 - 224 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=2 : 110 - 53 - 133 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=3 : 88 - 95 - 42 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=4 : 91 - 85 - 36 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=8 : 32 - 66 - 32 cycles(tsc)
>
> SLUB-original - bulk-API
> - SLUB-original: bulk_quick_reuse objects=1 : 87 - 87 - 142 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=2 : 52 - 53 - 53 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=3 : 42 - 42 - 91 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=4 : 91 - 37 - 37 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=8 : 31 - 79 - 76 cycles(tsc)
Your numbers for SLAB bulk-API:
SLAB-patched - bulk-API
- SLAB-patched : bulk_quick_reuse objects=1 : 67 - 67 - 140 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=2 : 55 - 46 - 46 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=3 : 93 - 94 - 39 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=4 : 35 - 88 - 85 cycles(tsc)
- SLAB-patched : bulk_quick_reuse objects=8 : 30 - 30 - 30 cycles(tsc)
SLAB-original- bulk-API
- SLAB-original: bulk_quick_reuse objects=1 : 143 - 136 - 67 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=2 : 45 - 46 - 46 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=3 : 38 - 39 - 39 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=4 : 35 - 87 - 87 cycles(tsc)
- SLAB-original: bulk_quick_reuse objects=8 : 29 - 66 - 30 cycles(tsc)
In case of SLAB I expect the bulk-API to be slightly faster than SLUB,
as the SLUB bulk code is much more advanced.
> Maybe it is just noise or instability in measurements, but it seem that the
> 1-object case is consistently slower in your patched version.
>
> Mail is too long now... I'll take a look at your SLAB results and followup.
(This is my follow up with SLAB results.)
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
Hi Roman,
On Mon, Jun 08, 2020 at 04:06:35PM -0700, Roman Gushchin wrote:
> This is v6 of the slab cgroup controller rework.
>
> The patchset moves the accounting from the page level to the object
> level. It allows to share slab pages between memory cgroups.
> This leads to a significant win in the slab utilization (up to 45%)
> and the corresponding drop in the total kernel memory footprint.
> The reduced number of unmovable slab pages should also have a positive
> effect on the memory fragmentation.
...
> Johannes Weiner (1):
> mm: memcontrol: decouple reference counting from page accounting
>
> Roman Gushchin (18):
> mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state()
> mm: memcg: prepare for byte-sized vmstat items
> mm: memcg: convert vmstat slab counters to bytes
> mm: slub: implement SLUB version of obj_to_index()
> mm: memcg/slab: obj_cgroup API
> mm: memcg/slab: allocate obj_cgroups for non-root slab pages
> mm: memcg/slab: save obj_cgroup for non-root slab objects
> mm: memcg/slab: charge individual slab objects instead of pages
> mm: memcg/slab: deprecate memory.kmem.slabinfo
> mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h
> mm: memcg/slab: use a single set of kmem_caches for all accounted allocations
> mm: memcg/slab: simplify memcg cache creation
> mm: memcg/slab: remove memcg_kmem_get_cache()
> mm: memcg/slab: deprecate slab_root_caches
> mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo()
> mm: memcg/slab: use a single set of kmem_caches for all allocations
> kselftests: cgroup: add kernel memory accounting tests
> tools/cgroup: add memcg_slabinfo.py tool
Sorry for jumping late, but I'm really missing
Documentation/vm/cgroup-slab.rst | < lots of + >
in this series ;-)
> drivers/base/node.c | 6 +-
> fs/proc/meminfo.c | 4 +-
> include/linux/memcontrol.h | 85 ++-
> include/linux/mm_types.h | 5 +-
> include/linux/mmzone.h | 24 +-
> include/linux/slab.h | 5 -
> include/linux/slab_def.h | 9 +-
> include/linux/slub_def.h | 31 +-
> include/linux/vmstat.h | 14 +-
> kernel/power/snapshot.c | 2 +-
> mm/memcontrol.c | 608 +++++++++++--------
> mm/oom_kill.c | 2 +-
> mm/page_alloc.c | 8 +-
> mm/slab.c | 70 +--
> mm/slab.h | 372 +++++-------
> mm/slab_common.c | 643 +--------------------
> mm/slob.c | 12 +-
> mm/slub.c | 229 +-------
> mm/vmscan.c | 3 +-
> mm/vmstat.c | 30 +-
> mm/workingset.c | 6 +-
> tools/cgroup/memcg_slabinfo.py | 226 ++++++++
> tools/testing/selftests/cgroup/.gitignore | 1 +
> tools/testing/selftests/cgroup/Makefile | 2 +
> tools/testing/selftests/cgroup/test_kmem.c | 382 ++++++++++++
> 25 files changed, 1374 insertions(+), 1405 deletions(-)
> create mode 100755 tools/cgroup/memcg_slabinfo.py
> create mode 100644 tools/testing/selftests/cgroup/test_kmem.c
>
> --
> 2.25.4
>
>
--
Sincerely yours,
Mike.
On Wed, 17 Jun 2020 18:29:28 -0700
Roman Gushchin <[email protected]> wrote:
> On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > On 6/17/20 5:32 AM, Roman Gushchin wrote:
> > > On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> > >> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> > >> >
> > >> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > >> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > >> > > >
> > >> [...]
> > >> > >
> > >> > > Have you performed any [perf] testing on SLAB with this patchset?
> > >> >
> > >> > The accounting part is the same for SLAB and SLUB, so there should be no
> > >> > significant difference. I've checked that it compiles, boots and passes
> > >> > kselftests. And that memory savings are there.
> > >> >
> > >>
> > >> What about performance? Also you mentioned that sharing kmem-cache
> > >> between accounted and non-accounted can have additional overhead. Any
> > >> difference between SLAB and SLUB for such a case?
> > >
> > > Not really.
> > >
> > > Sharing a single set of caches adds some overhead to root- and non-accounted
> > > allocations, which is something I've tried hard to avoid in my original version.
> > > But I have to admit, it allows to simplify and remove a lot of code, and here
> > > it's hard to argue with Johanness, who pushed on this design.
> > >
> > > With performance testing it's not that easy, because it's not obvious what
> > > we wanna test. Obviously, per-object accounting is more expensive, and
> > > measuring something like 1000000 allocations and deallocations in a line from
> > > a single kmem_cache will show a regression. But in the real world the relative
> > > cost of allocations is usually low, and we can get some benefits from a smaller
> > > working set and from having shared kmem_cache objects cache hot.
> > > Not speaking about some extra memory and the fragmentation reduction.
> > >
> > > We've done an extensive testing of the original version in Facebook production,
> > > and we haven't noticed any regressions so far. But I have to admit, we were
> > > using an original version with two sets of kmem_caches.
> > >
> > > If you have any specific tests in mind, I can definitely run them. Or if you
> > > can help with the performance evaluation, I'll appreciate it a lot.
> >
> > Jesper provided some pointers here [1], it would be really great if you could
> > run at least those microbenchmarks. With mmtests it's the major question of
> > which subset/profiles to run, maybe the referenced commits provide some hints,
> > or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
> >
> > [1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
>
> Oh, Jesper, I'm really sorry, somehow I missed your mail.
> Thank you, Vlastimil, for pointing at it.
>
> I've got some results (slab_bulk_test01), but honestly I fail to interpret them.
>
> I ran original vs patched with SLUB and SLAB, each test several times and picked
> 3 which looked most consistently. But it still looks very noisy.
>
> I ran them on my desktop (8-core Ryzen 1700, 16 GB RAM, Fedora 32),
> it's 5.8-rc1 + slab controller v6 vs 5.8-rc1 (default config from Fedora 32).
What about running these tests on the server level hardware, that you
intent to run this on?
>
> How should I interpret this data?
First of all these SLUB+SLAB microbenchmarks use object size 256 bytes,
because network stack alloc object of this size for SKBs/sk_buff (due
to cache-align as used size is 224 bytes). Checked SLUB: Each slab use
2 pages (8192 bytes) and contain 32 object of size 256 (256*32=8192).
The SLUB allocator have a per-CPU slab which speedup fast-reuse, in this
case up-to 32 objects. For SLUB the "fastpath reuse" test this behaviour,
and it serves as a baseline for optimal 1-object performance (where my bulk
API tries to beat that, which is possible even for 1-object due to knowing
bulk API cannot be used from IRQ context).
SLUB fastpath: 3 measurements reporting cycles(tsc)
- SLUB-patched : fastpath reuse: 184 - 177 - 176 cycles(tsc)
- SLUB-original: fastpath reuse: 178 - 153 - 156 cycles(tsc)
There are some stability concerns as you mention, but it seems pretty
consistently that patched version is slower. If you compile with
no-PREEMPT you can likely get more stable results (and remove a slight
overhead for SLUB fastpath).
The microbenchmark also measures the bulk-API, which is AFAIK only used
by network stack (and io_uring). I guess you shouldn't focus too much
on these bulk measurements. When bulk-API cross this objects per slab
threshold, or is unlucky is it use two per-CPU slab, then the
measurements can fluctuate a bit.
Your numbers for SLUB bulk-API:
SLUB-patched - bulk-API
- SLUB-patched : bulk_quick_reuse objects=1 : 187 - 90 - 224 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=2 : 110 - 53 - 133 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=3 : 88 - 95 - 42 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=4 : 91 - 85 - 36 cycles(tsc)
- SLUB-patched : bulk_quick_reuse objects=8 : 32 - 66 - 32 cycles(tsc)
SLUB-original - bulk-API
- SLUB-original: bulk_quick_reuse objects=1 : 87 - 87 - 142 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=2 : 52 - 53 - 53 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=3 : 42 - 42 - 91 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=4 : 91 - 37 - 37 cycles(tsc)
- SLUB-original: bulk_quick_reuse objects=8 : 31 - 79 - 76 cycles(tsc)
Maybe it is just noise or instability in measurements, but it seem that the
1-object case is consistently slower in your patched version.
Mail is too long now... I'll take a look at your SLAB results and followup.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
> --
>
> SLUB:
>
> Patched:
> [ 444.395174] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.773 ns (step:0) - (measurement period time:0.077335091 sec time_interval:77335091) - (invoke count:100000000 tsc_interval:231555960)
> [ 445.012669] time_bench: Type:kmem fastpath reuse Per elem: 184 cycles(tsc) 61.747 ns (step:0) - (measurement period time:0.617475365 sec time_interval:617475365) - (invoke count:10000000 tsc_interval:1848850440)
> [ 445.703843] time_bench: Type:kmem bulk_fallback Per elem: 206 cycles(tsc) 69.115 ns (step:1) - (measurement period time:0.691150675 sec time_interval:691150675) - (invoke count:10000000 tsc_interval:2069450250)
> [ 446.329396] time_bench: Type:kmem bulk_quick_reuse Per elem: 187 cycles(tsc) 62.554 ns (step:1) - (measurement period time:0.625541838 sec time_interval:625541838) - (invoke count:10000000 tsc_interval:1873003020)
> [ 446.975616] time_bench: Type:kmem bulk_fallback Per elem: 193 cycles(tsc) 64.622 ns (step:2) - (measurement period time:0.646223732 sec time_interval:646223732) - (invoke count:10000000 tsc_interval:1934929440)
> [ 447.345512] time_bench: Type:kmem bulk_quick_reuse Per elem: 110 cycles(tsc) 36.988 ns (step:2) - (measurement period time:0.369885352 sec time_interval:369885352) - (invoke count:10000000 tsc_interval:1107514050)
> [ 447.986272] time_bench: Type:kmem bulk_fallback Per elem: 191 cycles(tsc) 64.075 ns (step:3) - (measurement period time:0.640756304 sec time_interval:640756304) - (invoke count:9999999 tsc_interval:1918559070)
> [ 448.282163] time_bench: Type:kmem bulk_quick_reuse Per elem: 88 cycles(tsc) 29.586 ns (step:3) - (measurement period time:0.295866328 sec time_interval:295866328) - (invoke count:9999999 tsc_interval:885885270)
> [ 448.623183] time_bench: Type:kmem bulk_fallback Per elem: 102 cycles(tsc) 34.100 ns (step:4) - (measurement period time:0.341005290 sec time_interval:341005290) - (invoke count:10000000 tsc_interval:1021040820)
> [ 448.930228] time_bench: Type:kmem bulk_quick_reuse Per elem: 91 cycles(tsc) 30.702 ns (step:4) - (measurement period time:0.307020500 sec time_interval:307020500) - (invoke count:10000000 tsc_interval:919282860)
> [ 449.739697] time_bench: Type:kmem bulk_fallback Per elem: 242 cycles(tsc) 80.946 ns (step:8) - (measurement period time:0.809465825 sec time_interval:809465825) - (invoke count:10000000 tsc_interval:2423710560)
> [ 449.848110] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.836 ns (step:8) - (measurement period time:0.108363638 sec time_interval:108363638) - (invoke count:10000000 tsc_interval:324462540)
> [ 450.617892] time_bench: Type:kmem bulk_fallback Per elem: 230 cycles(tsc) 76.978 ns (step:16) - (measurement period time:0.769783892 sec time_interval:769783892) - (invoke count:10000000 tsc_interval:2304894090)
> [ 450.719556] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.164 ns (step:16) - (measurement period time:0.101645837 sec time_interval:101645837) - (invoke count:10000000 tsc_interval:304348440)
> [ 451.025387] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.580 ns (step:30) - (measurement period time:0.305803321 sec time_interval:305803321) - (invoke count:9999990 tsc_interval:915639450)
> [ 451.277708] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.229 ns (step:30) - (measurement period time:0.252294821 sec time_interval:252294821) - (invoke count:9999990 tsc_interval:755422110)
> [ 451.709305] time_bench: Type:kmem bulk_fallback Per elem: 129 cycles(tsc) 43.158 ns (step:32) - (measurement period time:0.431581619 sec time_interval:431581619) - (invoke count:10000000 tsc_interval:1292245320)
> [ 451.810686] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.135 ns (step:32) - (measurement period time:0.101357841 sec time_interval:101357841) - (invoke count:10000000 tsc_interval:303485250)
> [ 452.186138] time_bench: Type:kmem bulk_fallback Per elem: 112 cycles(tsc) 37.545 ns (step:34) - (measurement period time:0.375453243 sec time_interval:375453243) - (invoke count:9999978 tsc_interval:1124185320)
> [ 452.304950] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.880 ns (step:34) - (measurement period time:0.118800736 sec time_interval:118800736) - (invoke count:9999978 tsc_interval:355713360)
> [ 452.658607] time_bench: Type:kmem bulk_fallback Per elem: 105 cycles(tsc) 35.362 ns (step:48) - (measurement period time:0.353623065 sec time_interval:353623065) - (invoke count:9999984 tsc_interval:1058820960)
> [ 452.891623] time_bench: Type:kmem bulk_quick_reuse Per elem: 69 cycles(tsc) 23.298 ns (step:48) - (measurement period time:0.232988291 sec time_interval:232988291) - (invoke count:9999984 tsc_interval:697614570)
> [ 453.237406] time_bench: Type:kmem bulk_fallback Per elem: 103 cycles(tsc) 34.578 ns (step:64) - (measurement period time:0.345780444 sec time_interval:345780444) - (invoke count:10000000 tsc_interval:1035338790)
> [ 453.344946] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.750 ns (step:64) - (measurement period time:0.107500964 sec time_interval:107500964) - (invoke count:10000000 tsc_interval:321880290)
> [ 454.249297] time_bench: Type:kmem bulk_fallback Per elem: 270 cycles(tsc) 90.434 ns (step:128) - (measurement period time:0.904340126 sec time_interval:904340126) - (invoke count:10000000 tsc_interval:2707784610)
> [ 454.582548] time_bench: Type:kmem bulk_quick_reuse Per elem: 99 cycles(tsc) 33.322 ns (step:128) - (measurement period time:0.333226211 sec time_interval:333226211) - (invoke count:10000000 tsc_interval:997748760)
> [ 454.965002] time_bench: Type:kmem bulk_fallback Per elem: 114 cycles(tsc) 38.241 ns (step:158) - (measurement period time:0.382415227 sec time_interval:382415227) - (invoke count:9999978 tsc_interval:1145031120)
> [ 455.314105] time_bench: Type:kmem bulk_quick_reuse Per elem: 104 cycles(tsc) 34.908 ns (step:158) - (measurement period time:0.349080430 sec time_interval:349080430) - (invoke count:9999978 tsc_interval:1045219530)
> [ 455.699089] time_bench: Type:kmem bulk_fallback Per elem: 115 cycles(tsc) 38.495 ns (step:250) - (measurement period time:0.384953654 sec time_interval:384953654) - (invoke count:10000000 tsc_interval:1152631920)
> [ 456.104244] time_bench: Type:kmem bulk_quick_reuse Per elem: 121 cycles(tsc) 40.513 ns (step:250) - (measurement period time:0.405138149 sec time_interval:405138149) - (invoke count:10000000 tsc_interval:1213068180)
>
> [ 465.696654] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.772 ns (step:0) - (measurement period time:0.077270577 sec time_interval:77270577) - (invoke count:100000000 tsc_interval:231363840)
> [ 466.290176] time_bench: Type:kmem fastpath reuse Per elem: 177 cycles(tsc) 59.349 ns (step:0) - (measurement period time:0.593496780 sec time_interval:593496780) - (invoke count:10000000 tsc_interval:1777053420)
> [ 466.629838] time_bench: Type:kmem bulk_fallback Per elem: 101 cycles(tsc) 33.965 ns (step:1) - (measurement period time:0.339652351 sec time_interval:339652351) - (invoke count:10000000 tsc_interval:1016989230)
> [ 466.933290] time_bench: Type:kmem bulk_quick_reuse Per elem: 90 cycles(tsc) 30.344 ns (step:1) - (measurement period time:0.303444180 sec time_interval:303444180) - (invoke count:10000000 tsc_interval:908575380)
> [ 467.250189] time_bench: Type:kmem bulk_fallback Per elem: 94 cycles(tsc) 31.689 ns (step:2) - (measurement period time:0.316896073 sec time_interval:316896073) - (invoke count:10000000 tsc_interval:948853110)
> [ 467.430142] time_bench: Type:kmem bulk_quick_reuse Per elem: 53 cycles(tsc) 17.994 ns (step:2) - (measurement period time:0.179940800 sec time_interval:179940800) - (invoke count:10000000 tsc_interval:538779390)
> [ 467.780573] time_bench: Type:kmem bulk_fallback Per elem: 104 cycles(tsc) 35.039 ns (step:3) - (measurement period time:0.350394226 sec time_interval:350394226) - (invoke count:9999999 tsc_interval:1049153580)
> [ 468.100301] time_bench: Type:kmem bulk_quick_reuse Per elem: 95 cycles(tsc) 31.970 ns (step:3) - (measurement period time:0.319706687 sec time_interval:319706687) - (invoke count:9999999 tsc_interval:957267660)
> [ 468.792650] time_bench: Type:kmem bulk_fallback Per elem: 207 cycles(tsc) 69.235 ns (step:4) - (measurement period time:0.692354598 sec time_interval:692354598) - (invoke count:10000000 tsc_interval:2073054750)
> [ 469.078816] time_bench: Type:kmem bulk_quick_reuse Per elem: 85 cycles(tsc) 28.614 ns (step:4) - (measurement period time:0.286145162 sec time_interval:286145162) - (invoke count:10000000 tsc_interval:856777710)
> [ 469.694558] time_bench: Type:kmem bulk_fallback Per elem: 184 cycles(tsc) 61.573 ns (step:8) - (measurement period time:0.615733224 sec time_interval:615733224) - (invoke count:10000000 tsc_interval:1843634190)
> [ 469.917439] time_bench: Type:kmem bulk_quick_reuse Per elem: 66 cycles(tsc) 22.284 ns (step:8) - (measurement period time:0.222848937 sec time_interval:222848937) - (invoke count:10000000 tsc_interval:667255740)
> [ 470.586966] time_bench: Type:kmem bulk_fallback Per elem: 200 cycles(tsc) 66.952 ns (step:16) - (measurement period time:0.669526473 sec time_interval:669526473) - (invoke count:10000000 tsc_interval:2004702960)
> [ 470.794012] time_bench: Type:kmem bulk_quick_reuse Per elem: 61 cycles(tsc) 20.697 ns (step:16) - (measurement period time:0.206972335 sec time_interval:206972335) - (invoke count:10000000 tsc_interval:619717170)
> [ 471.422674] time_bench: Type:kmem bulk_fallback Per elem: 188 cycles(tsc) 62.866 ns (step:30) - (measurement period time:0.628659634 sec time_interval:628659634) - (invoke count:9999990 tsc_interval:1882338990)
> [ 471.524193] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.149 ns (step:30) - (measurement period time:0.101497972 sec time_interval:101497972) - (invoke count:9999990 tsc_interval:303905340)
> [ 471.829474] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.527 ns (step:32) - (measurement period time:0.305271485 sec time_interval:305271485) - (invoke count:10000000 tsc_interval:914046510)
> [ 471.930490] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.099 ns (step:32) - (measurement period time:0.100992877 sec time_interval:100992877) - (invoke count:10000000 tsc_interval:302392890)
> [ 472.311211] time_bench: Type:kmem bulk_fallback Per elem: 113 cycles(tsc) 38.072 ns (step:34) - (measurement period time:0.380725777 sec time_interval:380725777) - (invoke count:9999978 tsc_interval:1139972850)
> [ 472.429823] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.860 ns (step:34) - (measurement period time:0.118599617 sec time_interval:118599617) - (invoke count:9999978 tsc_interval:355111890)
> [ 472.890092] time_bench: Type:kmem bulk_fallback Per elem: 137 cycles(tsc) 46.026 ns (step:48) - (measurement period time:0.460264730 sec time_interval:460264730) - (invoke count:9999984 tsc_interval:1378127970)
> [ 472.999481] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.937 ns (step:48) - (measurement period time:0.109371593 sec time_interval:109371593) - (invoke count:9999984 tsc_interval:327480390)
> [ 473.344109] time_bench: Type:kmem bulk_fallback Per elem: 103 cycles(tsc) 34.462 ns (step:64) - (measurement period time:0.344629774 sec time_interval:344629774) - (invoke count:10000000 tsc_interval:1031893740)
> [ 473.452099] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.794 ns (step:64) - (measurement period time:0.107942846 sec time_interval:107942846) - (invoke count:10000000 tsc_interval:323202390)
> [ 474.382899] time_bench: Type:kmem bulk_fallback Per elem: 278 cycles(tsc) 93.080 ns (step:128) - (measurement period time:0.930809025 sec time_interval:930809025) - (invoke count:10000000 tsc_interval:2787037260)
> [ 474.729757] time_bench: Type:kmem bulk_quick_reuse Per elem: 103 cycles(tsc) 34.683 ns (step:128) - (measurement period time:0.346831572 sec time_interval:346831572) - (invoke count:10000000 tsc_interval:1038484980)
> [ 475.616707] time_bench: Type:kmem bulk_fallback Per elem: 265 cycles(tsc) 88.693 ns (step:158) - (measurement period time:0.886937188 sec time_interval:886937188) - (invoke count:9999978 tsc_interval:2655675660)
> [ 475.890425] time_bench: Type:kmem bulk_quick_reuse Per elem: 81 cycles(tsc) 27.369 ns (step:158) - (measurement period time:0.273692416 sec time_interval:273692416) - (invoke count:9999978 tsc_interval:819491040)
> [ 476.275144] time_bench: Type:kmem bulk_fallback Per elem: 115 cycles(tsc) 38.471 ns (step:250) - (measurement period time:0.384713160 sec time_interval:384713160) - (invoke count:10000000 tsc_interval:1151911110)
> [ 476.424219] time_bench: Type:kmem bulk_quick_reuse Per elem: 44 cycles(tsc) 14.906 ns (step:250) - (measurement period time:0.149068364 sec time_interval:149068364) - (invoke count:10000000 tsc_interval:446341830)
>
> [ 490.306824] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.776 ns (step:0) - (measurement period time:0.077691991 sec time_interval:77691991) - (invoke count:100000000 tsc_interval:232625850)
> [ 490.897035] time_bench: Type:kmem fastpath reuse Per elem: 176 cycles(tsc) 59.019 ns (step:0) - (measurement period time:0.590195120 sec time_interval:590195120) - (invoke count:10000000 tsc_interval:1767174930)
> [ 491.590675] time_bench: Type:kmem bulk_fallback Per elem: 207 cycles(tsc) 69.362 ns (step:1) - (measurement period time:0.693628128 sec time_interval:693628128) - (invoke count:10000000 tsc_interval:2076877050)
> [ 492.339461] time_bench: Type:kmem bulk_quick_reuse Per elem: 224 cycles(tsc) 74.877 ns (step:1) - (measurement period time:0.748777171 sec time_interval:748777171) - (invoke count:10000000 tsc_interval:2242005540)
> [ 493.129328] time_bench: Type:kmem bulk_fallback Per elem: 236 cycles(tsc) 78.984 ns (step:2) - (measurement period time:0.789848781 sec time_interval:789848781) - (invoke count:10000000 tsc_interval:2364983220)
> [ 493.574670] time_bench: Type:kmem bulk_quick_reuse Per elem: 133 cycles(tsc) 44.530 ns (step:2) - (measurement period time:0.445304096 sec time_interval:445304096) - (invoke count:10000000 tsc_interval:1333339110)
> [ 493.887021] time_bench: Type:kmem bulk_fallback Per elem: 93 cycles(tsc) 31.231 ns (step:3) - (measurement period time:0.312316389 sec time_interval:312316389) - (invoke count:9999999 tsc_interval:935143950)
> [ 494.029383] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.234 ns (step:3) - (measurement period time:0.142346254 sec time_interval:142346254) - (invoke count:9999999 tsc_interval:426216000)
> [ 494.369892] time_bench: Type:kmem bulk_fallback Per elem: 101 cycles(tsc) 34.050 ns (step:4) - (measurement period time:0.340504527 sec time_interval:340504527) - (invoke count:10000000 tsc_interval:1019546130)
> [ 494.493217] time_bench: Type:kmem bulk_quick_reuse Per elem: 36 cycles(tsc) 12.329 ns (step:4) - (measurement period time:0.123294475 sec time_interval:123294475) - (invoke count:10000000 tsc_interval:369169800)
> [ 494.820003] time_bench: Type:kmem bulk_fallback Per elem: 97 cycles(tsc) 32.678 ns (step:8) - (measurement period time:0.326780876 sec time_interval:326780876) - (invoke count:10000000 tsc_interval:978453960)
> [ 494.928831] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.880 ns (step:8) - (measurement period time:0.108808086 sec time_interval:108808086) - (invoke count:10000000 tsc_interval:325794570)
> [ 495.684358] time_bench: Type:kmem bulk_fallback Per elem: 226 cycles(tsc) 75.552 ns (step:16) - (measurement period time:0.755527917 sec time_interval:755527917) - (invoke count:10000000 tsc_interval:2262218520)
> [ 495.785682] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.130 ns (step:16) - (measurement period time:0.101307607 sec time_interval:101307607) - (invoke count:10000000 tsc_interval:303336720)
> [ 496.090994] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.528 ns (step:30) - (measurement period time:0.305280433 sec time_interval:305280433) - (invoke count:9999990 tsc_interval:914077290)
> [ 496.341570] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.054 ns (step:30) - (measurement period time:0.250548825 sec time_interval:250548825) - (invoke count:9999990 tsc_interval:750197910)
> [ 496.646784] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.518 ns (step:32) - (measurement period time:0.305189218 sec time_interval:305189218) - (invoke count:10000000 tsc_interval:913803540)
> [ 496.900311] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.349 ns (step:32) - (measurement period time:0.253499465 sec time_interval:253499465) - (invoke count:10000000 tsc_interval:759033060)
> [ 497.778600] time_bench: Type:kmem bulk_fallback Per elem: 262 cycles(tsc) 87.830 ns (step:34) - (measurement period time:0.878298604 sec time_interval:878298604) - (invoke count:9999978 tsc_interval:2629821090)
> [ 498.043690] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.506 ns (step:34) - (measurement period time:0.265066374 sec time_interval:265066374) - (invoke count:9999978 tsc_interval:793667400)
> [ 498.393912] time_bench: Type:kmem bulk_fallback Per elem: 104 cycles(tsc) 35.021 ns (step:48) - (measurement period time:0.350216735 sec time_interval:350216735) - (invoke count:9999984 tsc_interval:1048626840)
> [ 498.504846] time_bench: Type:kmem bulk_quick_reuse Per elem: 33 cycles(tsc) 11.092 ns (step:48) - (measurement period time:0.110924201 sec time_interval:110924201) - (invoke count:9999984 tsc_interval:332131200)
> [ 498.878335] time_bench: Type:kmem bulk_fallback Per elem: 111 cycles(tsc) 37.345 ns (step:64) - (measurement period time:0.373454272 sec time_interval:373454272) - (invoke count:10000000 tsc_interval:1118205060)
> [ 499.145467] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.710 ns (step:64) - (measurement period time:0.267102714 sec time_interval:267102714) - (invoke count:10000000 tsc_interval:799763910)
> [ 499.525255] time_bench: Type:kmem bulk_fallback Per elem: 113 cycles(tsc) 37.971 ns (step:128) - (measurement period time:0.379715035 sec time_interval:379715035) - (invoke count:10000000 tsc_interval:1136951190)
> [ 499.852495] time_bench: Type:kmem bulk_quick_reuse Per elem: 97 cycles(tsc) 32.721 ns (step:128) - (measurement period time:0.327218329 sec time_interval:327218329) - (invoke count:10000000 tsc_interval:979763670)
> [ 500.238889] time_bench: Type:kmem bulk_fallback Per elem: 115 cycles(tsc) 38.638 ns (step:158) - (measurement period time:0.386388112 sec time_interval:386388112) - (invoke count:9999978 tsc_interval:1156931610)
> [ 500.370790] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.189 ns (step:158) - (measurement period time:0.131890805 sec time_interval:131890805) - (invoke count:9999978 tsc_interval:394909920)
> [ 500.747241] time_bench: Type:kmem bulk_fallback Per elem: 112 cycles(tsc) 37.645 ns (step:250) - (measurement period time:0.376455749 sec time_interval:376455749) - (invoke count:10000000 tsc_interval:1127192310)
> [ 500.897248] time_bench: Type:kmem bulk_quick_reuse Per elem: 44 cycles(tsc) 14.999 ns (step:250) - (measurement period time:0.149997635 sec time_interval:149997635) - (invoke count:10000000 tsc_interval:449125920)
>
> Orig:
> [ 81.987064] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.813 ns (step:0) - (measurement period time:0.081397445 sec time_interval:81397445) - (invoke count:100000000 tsc_interval:243727920)
> [ 82.595831] time_bench: Type:kmem fastpath reuse Per elem: 178 cycles(tsc) 59.675 ns (step:0) - (measurement period time:0.596752095 sec time_interval:596752095) - (invoke count:10000000 tsc_interval:1786857030)
> [ 83.031850] time_bench: Type:kmem bulk_fallback Per elem: 127 cycles(tsc) 42.541 ns (step:1) - (measurement period time:0.425415790 sec time_interval:425415790) - (invoke count:10000000 tsc_interval:1273823670)
> [ 83.340838] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.200 ns (step:1) - (measurement period time:0.292006301 sec time_interval:292006301) - (invoke count:10000000 tsc_interval:874355190)
> [ 83.630781] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.923 ns (step:2) - (measurement period time:0.279231691 sec time_interval:279231691) - (invoke count:10000000 tsc_interval:836104170)
> [ 83.821746] time_bench: Type:kmem bulk_quick_reuse Per elem: 52 cycles(tsc) 17.611 ns (step:2) - (measurement period time:0.176116770 sec time_interval:176116770) - (invoke count:10000000 tsc_interval:527346570)
> [ 84.105841] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.184 ns (step:3) - (measurement period time:0.271845630 sec time_interval:271845630) - (invoke count:9999999 tsc_interval:813988260)
> [ 84.257733] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.120 ns (step:3) - (measurement period time:0.141208965 sec time_interval:141208965) - (invoke count:9999999 tsc_interval:422821890)
> [ 84.578730] time_bench: Type:kmem bulk_fallback Per elem: 92 cycles(tsc) 30.798 ns (step:4) - (measurement period time:0.307982589 sec time_interval:307982589) - (invoke count:10000000 tsc_interval:922193070)
> [ 84.894740] time_bench: Type:kmem bulk_quick_reuse Per elem: 91 cycles(tsc) 30.523 ns (step:4) - (measurement period time:0.305231656 sec time_interval:305231656) - (invoke count:10000000 tsc_interval:913955310)
> [ 85.596699] time_bench: Type:kmem bulk_fallback Per elem: 206 cycles(tsc) 68.977 ns (step:8) - (measurement period time:0.689779758 sec time_interval:689779758) - (invoke count:10000000 tsc_interval:2065410030)
> [ 85.728679] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.641 ns (step:8) - (measurement period time:0.106415387 sec time_interval:106415387) - (invoke count:10000000 tsc_interval:318639630)
> [ 86.016723] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.302 ns (step:16) - (measurement period time:0.273021863 sec time_interval:273021863) - (invoke count:10000000 tsc_interval:817509990)
> [ 86.137711] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 10.005 ns (step:16) - (measurement period time:0.100053210 sec time_interval:100053210) - (invoke count:10000000 tsc_interval:299589180)
> [ 86.420698] time_bench: Type:kmem bulk_fallback Per elem: 79 cycles(tsc) 26.598 ns (step:30) - (measurement period time:0.265984644 sec time_interval:265984644) - (invoke count:9999990 tsc_interval:796437960)
> [ 86.534652] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.742 ns (step:30) - (measurement period time:0.097425391 sec time_interval:97425391) - (invoke count:9999990 tsc_interval:291720810)
> [ 86.812682] time_bench: Type:kmem bulk_fallback Per elem: 79 cycles(tsc) 26.522 ns (step:32) - (measurement period time:0.265225864 sec time_interval:265225864) - (invoke count:10000000 tsc_interval:794166360)
> [ 86.923650] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.729 ns (step:32) - (measurement period time:0.097294552 sec time_interval:97294552) - (invoke count:10000000 tsc_interval:291328800)
> [ 87.255647] time_bench: Type:kmem bulk_fallback Per elem: 95 cycles(tsc) 32.050 ns (step:34) - (measurement period time:0.320499429 sec time_interval:320499429) - (invoke count:9999978 tsc_interval:959672160)
> [ 87.383687] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.492 ns (step:34) - (measurement period time:0.114921393 sec time_interval:114921393) - (invoke count:9999978 tsc_interval:344109030)
> [ 87.724663] time_bench: Type:kmem bulk_fallback Per elem: 96 cycles(tsc) 32.346 ns (step:48) - (measurement period time:0.323463245 sec time_interval:323463245) - (invoke count:9999984 tsc_interval:968546670)
> [ 87.847640] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.661 ns (step:48) - (measurement period time:0.106610938 sec time_interval:106610938) - (invoke count:9999984 tsc_interval:319225170)
> [ 88.167636] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.678 ns (step:64) - (measurement period time:0.306781428 sec time_interval:306781428) - (invoke count:10000000 tsc_interval:918596670)
> [ 88.287645] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.677 ns (step:64) - (measurement period time:0.106773747 sec time_interval:106773747) - (invoke count:10000000 tsc_interval:319712640)
> [ 88.634627] time_bench: Type:kmem bulk_fallback Per elem: 100 cycles(tsc) 33.591 ns (step:128) - (measurement period time:0.335914141 sec time_interval:335914141) - (invoke count:10000000 tsc_interval:1005828930)
> [ 88.785630] time_bench: Type:kmem bulk_quick_reuse Per elem: 40 cycles(tsc) 13.648 ns (step:128) - (measurement period time:0.136483174 sec time_interval:136483174) - (invoke count:10000000 tsc_interval:408671550)
> [ 89.138604] time_bench: Type:kmem bulk_fallback Per elem: 101 cycles(tsc) 33.981 ns (step:158) - (measurement period time:0.339814415 sec time_interval:339814415) - (invoke count:9999978 tsc_interval:1017507030)
> [ 89.289633] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.110 ns (step:158) - (measurement period time:0.141101621 sec time_interval:141101621) - (invoke count:9999978 tsc_interval:422500530)
> [ 89.650638] time_bench: Type:kmem bulk_fallback Per elem: 104 cycles(tsc) 34.887 ns (step:250) - (measurement period time:0.348876887 sec time_interval:348876887) - (invoke count:10000000 tsc_interval:1044643320)
> [ 89.813613] time_bench: Type:kmem bulk_quick_reuse Per elem: 44 cycles(tsc) 14.821 ns (step:250) - (measurement period time:0.148213151 sec time_interval:148213151) - (invoke count:10000000 tsc_interval:443794860)
>
> [ 120.495694] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.777 ns (step:0) - (measurement period time:0.077764814 sec time_interval:77764814) - (invoke count:100000000 tsc_interval:232850730)
> [ 121.018849] time_bench: Type:kmem fastpath reuse Per elem: 153 cycles(tsc) 51.274 ns (step:0) - (measurement period time:0.512740018 sec time_interval:512740018) - (invoke count:10000000 tsc_interval:1535297070)
> [ 121.326965] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.560 ns (step:1) - (measurement period time:0.305608844 sec time_interval:305608844) - (invoke count:10000000 tsc_interval:915084480)
> [ 121.628922] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.218 ns (step:1) - (measurement period time:0.292184439 sec time_interval:292184439) - (invoke count:10000000 tsc_interval:874887840)
> [ 122.337817] time_bench: Type:kmem bulk_fallback Per elem: 207 cycles(tsc) 69.361 ns (step:2) - (measurement period time:0.693612284 sec time_interval:693612284) - (invoke count:10000000 tsc_interval:2076883890)
> [ 122.520912] time_bench: Type:kmem bulk_quick_reuse Per elem: 53 cycles(tsc) 17.741 ns (step:2) - (measurement period time:0.177417675 sec time_interval:177417675) - (invoke count:10000000 tsc_interval:531240870)
> [ 122.872912] time_bench: Type:kmem bulk_fallback Per elem: 102 cycles(tsc) 34.212 ns (step:3) - (measurement period time:0.342120142 sec time_interval:342120142) - (invoke count:9999999 tsc_interval:1024409910)
> [ 123.019909] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.084 ns (step:3) - (measurement period time:0.140842225 sec time_interval:140842225) - (invoke count:9999999 tsc_interval:421723650)
> [ 123.837965] time_bench: Type:kmem bulk_fallback Per elem: 241 cycles(tsc) 80.516 ns (step:4) - (measurement period time:0.805161046 sec time_interval:805161046) - (invoke count:10000000 tsc_interval:2410894650)
> [ 123.973915] time_bench: Type:kmem bulk_quick_reuse Per elem: 37 cycles(tsc) 12.377 ns (step:4) - (measurement period time:0.123773940 sec time_interval:123773940) - (invoke count:10000000 tsc_interval:370615290)
> [ 124.273862] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.860 ns (step:8) - (measurement period time:0.288604912 sec time_interval:288604912) - (invoke count:10000000 tsc_interval:864169920)
> [ 124.546757] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.420 ns (step:8) - (measurement period time:0.264207028 sec time_interval:264207028) - (invoke count:10000000 tsc_interval:791114430)
> [ 125.191730] time_bench: Type:kmem bulk_fallback Per elem: 190 cycles(tsc) 63.456 ns (step:16) - (measurement period time:0.634568513 sec time_interval:634568513) - (invoke count:10000000 tsc_interval:1900088820)
> [ 125.296839] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.043 ns (step:16) - (measurement period time:0.100439926 sec time_interval:100439926) - (invoke count:10000000 tsc_interval:300746670)
> [ 125.580743] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.347 ns (step:30) - (measurement period time:0.273471271 sec time_interval:273471271) - (invoke count:9999990 tsc_interval:818855040)
> [ 125.836734] time_bench: Type:kmem bulk_quick_reuse Per elem: 72 cycles(tsc) 24.372 ns (step:30) - (measurement period time:0.243727806 sec time_interval:243727806) - (invoke count:9999990 tsc_interval:729793590)
> [ 126.508883] time_bench: Type:kmem bulk_fallback Per elem: 197 cycles(tsc) 65.900 ns (step:32) - (measurement period time:0.659009779 sec time_interval:659009779) - (invoke count:10000000 tsc_interval:1973273460)
> [ 126.612891] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.749 ns (step:32) - (measurement period time:0.097491968 sec time_interval:97491968) - (invoke count:10000000 tsc_interval:291919890)
> [ 126.968798] time_bench: Type:kmem bulk_fallback Per elem: 103 cycles(tsc) 34.676 ns (step:34) - (measurement period time:0.346762028 sec time_interval:346762028) - (invoke count:9999978 tsc_interval:1038309510)
> [ 127.095700] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.648 ns (step:34) - (measurement period time:0.116483925 sec time_interval:116483925) - (invoke count:9999978 tsc_interval:348787590)
> [ 127.974794] time_bench: Type:kmem bulk_fallback Per elem: 259 cycles(tsc) 86.651 ns (step:48) - (measurement period time:0.866514663 sec time_interval:866514663) - (invoke count:9999984 tsc_interval:2594605770)
> [ 128.093772] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.426 ns (step:48) - (measurement period time:0.114267827 sec time_interval:114267827) - (invoke count:9999984 tsc_interval:342151620)
> [ 128.430665] time_bench: Type:kmem bulk_fallback Per elem: 97 cycles(tsc) 32.514 ns (step:64) - (measurement period time:0.325148101 sec time_interval:325148101) - (invoke count:10000000 tsc_interval:973590990)
> [ 128.546857] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.991 ns (step:64) - (measurement period time:0.109916673 sec time_interval:109916673) - (invoke count:10000000 tsc_interval:329123280)
> [ 129.431645] time_bench: Type:kmem bulk_fallback Per elem: 261 cycles(tsc) 87.191 ns (step:128) - (measurement period time:0.871911323 sec time_interval:871911323) - (invoke count:10000000 tsc_interval:2610764490)
> [ 129.583764] time_bench: Type:kmem bulk_quick_reuse Per elem: 43 cycles(tsc) 14.514 ns (step:128) - (measurement period time:0.145148532 sec time_interval:145148532) - (invoke count:10000000 tsc_interval:434617800)
> [ 130.443627] time_bench: Type:kmem bulk_fallback Per elem: 254 cycles(tsc) 84.982 ns (step:158) - (measurement period time:0.849826310 sec time_interval:849826310) - (invoke count:9999978 tsc_interval:2544635760)
> [ 130.583738] time_bench: Type:kmem bulk_quick_reuse Per elem: 40 cycles(tsc) 13.399 ns (step:158) - (measurement period time:0.133992977 sec time_interval:133992977) - (invoke count:9999978 tsc_interval:401214210)
> [ 130.947634] time_bench: Type:kmem bulk_fallback Per elem: 105 cycles(tsc) 35.206 ns (step:250) - (measurement period time:0.352068766 sec time_interval:352068766) - (invoke count:10000000 tsc_interval:1054199400)
> [ 131.268601] time_bench: Type:kmem bulk_quick_reuse Per elem: 93 cycles(tsc) 31.142 ns (step:250) - (measurement period time:0.311429067 sec time_interval:311429067) - (invoke count:10000000 tsc_interval:932511270)
>
> [ 135.584335] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.772 ns (step:0) - (measurement period time:0.077217374 sec time_interval:77217374) - (invoke count:100000000 tsc_interval:231211500)
> [ 136.122480] time_bench: Type:kmem fastpath reuse Per elem: 156 cycles(tsc) 52.212 ns (step:0) - (measurement period time:0.522120964 sec time_interval:522120964) - (invoke count:10000000 tsc_interval:1563386670)
> [ 136.762465] time_bench: Type:kmem bulk_fallback Per elem: 186 cycles(tsc) 62.301 ns (step:1) - (measurement period time:0.623010984 sec time_interval:623010984) - (invoke count:10000000 tsc_interval:1865481540)
> [ 137.248444] time_bench: Type:kmem bulk_quick_reuse Per elem: 142 cycles(tsc) 47.606 ns (step:1) - (measurement period time:0.476063536 sec time_interval:476063536) - (invoke count:10000000 tsc_interval:1425477150)
> [ 137.540440] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.282 ns (step:2) - (measurement period time:0.282824344 sec time_interval:282824344) - (invoke count:10000000 tsc_interval:846861210)
> [ 137.724456] time_bench: Type:kmem bulk_quick_reuse Per elem: 53 cycles(tsc) 17.830 ns (step:2) - (measurement period time:0.178304559 sec time_interval:178304559) - (invoke count:10000000 tsc_interval:533896980)
> [ 138.366442] time_bench: Type:kmem bulk_fallback Per elem: 189 cycles(tsc) 63.289 ns (step:3) - (measurement period time:0.632890657 sec time_interval:632890657) - (invoke count:9999999 tsc_interval:1895064930)
> [ 138.682405] time_bench: Type:kmem bulk_quick_reuse Per elem: 91 cycles(tsc) 30.603 ns (step:3) - (measurement period time:0.306034382 sec time_interval:306034382) - (invoke count:9999999 tsc_interval:916357950)
> [ 138.997539] time_bench: Type:kmem bulk_fallback Per elem: 90 cycles(tsc) 30.372 ns (step:4) - (measurement period time:0.303723704 sec time_interval:303723704) - (invoke count:10000000 tsc_interval:909440220)
> [ 139.131400] time_bench: Type:kmem bulk_quick_reuse Per elem: 37 cycles(tsc) 12.405 ns (step:4) - (measurement period time:0.124058230 sec time_interval:124058230) - (invoke count:10000000 tsc_interval:371467110)
> [ 139.430407] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.867 ns (step:8) - (measurement period time:0.288673242 sec time_interval:288673242) - (invoke count:10000000 tsc_interval:864374550)
> [ 139.694401] time_bench: Type:kmem bulk_quick_reuse Per elem: 76 cycles(tsc) 25.593 ns (step:8) - (measurement period time:0.255935939 sec time_interval:255935939) - (invoke count:10000000 tsc_interval:766348440)
> [ 140.387369] time_bench: Type:kmem bulk_fallback Per elem: 203 cycles(tsc) 68.061 ns (step:16) - (measurement period time:0.680610963 sec time_interval:680610963) - (invoke count:10000000 tsc_interval:2037954090)
> [ 140.495385] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.173 ns (step:16) - (measurement period time:0.101737300 sec time_interval:101737300) - (invoke count:10000000 tsc_interval:304631430)
> [ 141.101479] time_bench: Type:kmem bulk_fallback Per elem: 177 cycles(tsc) 59.116 ns (step:30) - (measurement period time:0.591165326 sec time_interval:591165326) - (invoke count:9999990 tsc_interval:1770126360)
> [ 141.350337] time_bench: Type:kmem bulk_quick_reuse Per elem: 72 cycles(tsc) 24.305 ns (step:30) - (measurement period time:0.243051460 sec time_interval:243051460) - (invoke count:9999990 tsc_interval:727767660)
> [ 141.781369] time_bench: Type:kmem bulk_fallback Per elem: 126 cycles(tsc) 42.191 ns (step:32) - (measurement period time:0.421915112 sec time_interval:421915112) - (invoke count:10000000 tsc_interval:1263340320)
> [ 142.029348] time_bench: Type:kmem bulk_quick_reuse Per elem: 72 cycles(tsc) 24.208 ns (step:32) - (measurement period time:0.242082250 sec time_interval:242082250) - (invoke count:10000000 tsc_interval:724865610)
> [ 142.833301] time_bench: Type:kmem bulk_fallback Per elem: 237 cycles(tsc) 79.313 ns (step:34) - (measurement period time:0.793128746 sec time_interval:793128746) - (invoke count:9999978 tsc_interval:2374865760)
> [ 142.957327] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.796 ns (step:34) - (measurement period time:0.117960158 sec time_interval:117960158) - (invoke count:9999978 tsc_interval:353207850)
> [ 143.714486] time_bench: Type:kmem bulk_fallback Per elem: 223 cycles(tsc) 74.629 ns (step:48) - (measurement period time:0.746296426 sec time_interval:746296426) - (invoke count:9999984 tsc_interval:2234635890)
> [ 143.998413] time_bench: Type:kmem bulk_quick_reuse Per elem: 82 cycles(tsc) 27.476 ns (step:48) - (measurement period time:0.274759868 sec time_interval:274759868) - (invoke count:9999984 tsc_interval:822712920)
> [ 144.717341] time_bench: Type:kmem bulk_fallback Per elem: 211 cycles(tsc) 70.598 ns (step:64) - (measurement period time:0.705984861 sec time_interval:705984861) - (invoke count:10000000 tsc_interval:2113930770)
> [ 144.838259] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.788 ns (step:64) - (measurement period time:0.107887319 sec time_interval:107887319) - (invoke count:10000000 tsc_interval:323046420)
> [ 145.190386] time_bench: Type:kmem bulk_fallback Per elem: 102 cycles(tsc) 34.174 ns (step:128) - (measurement period time:0.341741874 sec time_interval:341741874) - (invoke count:10000000 tsc_interval:1023278130)
> [ 145.514275] time_bench: Type:kmem bulk_quick_reuse Per elem: 93 cycles(tsc) 31.128 ns (step:128) - (measurement period time:0.311288149 sec time_interval:311288149) - (invoke count:10000000 tsc_interval:932088960)
> [ 146.367413] time_bench: Type:kmem bulk_fallback Per elem: 251 cycles(tsc) 84.015 ns (step:158) - (measurement period time:0.840153692 sec time_interval:840153692) - (invoke count:9999978 tsc_interval:2515672920)
> [ 146.523219] time_bench: Type:kmem bulk_quick_reuse Per elem: 42 cycles(tsc) 14.280 ns (step:158) - (measurement period time:0.142806094 sec time_interval:142806094) - (invoke count:9999978 tsc_interval:427603830)
> [ 146.888375] time_bench: Type:kmem bulk_fallback Per elem: 105 cycles(tsc) 35.119 ns (step:250) - (measurement period time:0.351191259 sec time_interval:351191259) - (invoke count:10000000 tsc_interval:1051571610)
> [ 147.291226] time_bench: Type:kmem bulk_quick_reuse Per elem: 117 cycles(tsc) 39.200 ns (step:250) - (measurement period time:0.392003176 sec time_interval:392003176) - (invoke count:10000000 tsc_interval:1173774360)
>
>
> SLAB:
>
> Orig:
> [ 80.499545] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.830 ns (step:0) - (measurement period time:0.083085912 sec time_interval:83085912) - (invoke count:100000000 tsc_interval:248781840)
> [ 81.099911] time_bench: Type:kmem fastpath reuse Per elem: 174 cycles(tsc) 58.430 ns (step:0) - (measurement period time:0.584308185 sec time_interval:584308185) - (invoke count:10000000 tsc_interval:1749584790)
> [ 81.421881] time_bench: Type:kmem bulk_fallback Per elem: 89 cycles(tsc) 30.019 ns (step:1) - (measurement period time:0.300198661 sec time_interval:300198661) - (invoke count:10000000 tsc_interval:898879710)
> [ 81.910960] time_bench: Type:kmem bulk_quick_reuse Per elem: 143 cycles(tsc) 47.889 ns (step:1) - (measurement period time:0.478893310 sec time_interval:478893310) - (invoke count:10000000 tsc_interval:1433941530)
> [ 82.583917] time_bench: Type:kmem bulk_fallback Per elem: 197 cycles(tsc) 65.813 ns (step:2) - (measurement period time:0.658134429 sec time_interval:658134429) - (invoke count:10000000 tsc_interval:1970640660)
> [ 82.751867] time_bench: Type:kmem bulk_quick_reuse Per elem: 45 cycles(tsc) 15.221 ns (step:2) - (measurement period time:0.152212195 sec time_interval:152212195) - (invoke count:10000000 tsc_interval:455766000)
> [ 83.047850] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.831 ns (step:3) - (measurement period time:0.278309326 sec time_interval:278309326) - (invoke count:9999999 tsc_interval:833336640)
> [ 83.186831] time_bench: Type:kmem bulk_quick_reuse Per elem: 38 cycles(tsc) 12.885 ns (step:3) - (measurement period time:0.128853000 sec time_interval:128853000) - (invoke count:9999999 tsc_interval:385821900)
> [ 83.514848] time_bench: Type:kmem bulk_fallback Per elem: 92 cycles(tsc) 30.901 ns (step:4) - (measurement period time:0.309012550 sec time_interval:309012550) - (invoke count:10000000 tsc_interval:925270980)
> [ 83.646835] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.711 ns (step:4) - (measurement period time:0.117116655 sec time_interval:117116655) - (invoke count:10000000 tsc_interval:350679900)
> [ 83.954817] time_bench: Type:kmem bulk_fallback Per elem: 89 cycles(tsc) 29.739 ns (step:8) - (measurement period time:0.297398266 sec time_interval:297398266) - (invoke count:10000000 tsc_interval:890494290)
> [ 84.069826] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.943 ns (step:8) - (measurement period time:0.099437599 sec time_interval:99437599) - (invoke count:10000000 tsc_interval:297743760)
> [ 84.361844] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.263 ns (step:16) - (measurement period time:0.282630878 sec time_interval:282630878) - (invoke count:10000000 tsc_interval:846277020)
> [ 84.471816] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.643 ns (step:16) - (measurement period time:0.096439729 sec time_interval:96439729) - (invoke count:10000000 tsc_interval:288767550)
> [ 84.977793] time_bench: Type:kmem bulk_fallback Per elem: 145 cycles(tsc) 48.452 ns (step:30) - (measurement period time:0.484520609 sec time_interval:484520609) - (invoke count:9999990 tsc_interval:1450791510)
> [ 85.222771] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 22.726 ns (step:30) - (measurement period time:0.227266268 sec time_interval:227266268) - (invoke count:9999990 tsc_interval:680498580)
> [ 85.814766] time_bench: Type:kmem bulk_fallback Per elem: 173 cycles(tsc) 57.907 ns (step:32) - (measurement period time:0.579072933 sec time_interval:579072933) - (invoke count:10000000 tsc_interval:1733908170)
> [ 85.914739] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.385 ns (step:32) - (measurement period time:0.093857661 sec time_interval:93857661) - (invoke count:10000000 tsc_interval:281035770)
> [ 86.207764] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.489 ns (step:34) - (measurement period time:0.274891966 sec time_interval:274891966) - (invoke count:9999978 tsc_interval:823104480)
> [ 86.452755] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 23.040 ns (step:34) - (measurement period time:0.230401610 sec time_interval:230401610) - (invoke count:9999978 tsc_interval:689886630)
> [ 86.736743] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.326 ns (step:48) - (measurement period time:0.273267062 sec time_interval:273267062) - (invoke count:9999984 tsc_interval:818238330)
> [ 86.839857] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.506 ns (step:48) - (measurement period time:0.095059470 sec time_interval:95059470) - (invoke count:9999984 tsc_interval:284634690)
> [ 87.432947] time_bench: Type:kmem bulk_fallback Per elem: 172 cycles(tsc) 57.565 ns (step:64) - (measurement period time:0.575650143 sec time_interval:575650143) - (invoke count:10000000 tsc_interval:1723659720)
> [ 87.536682] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.267 ns (step:64) - (measurement period time:0.092674016 sec time_interval:92674016) - (invoke count:10000000 tsc_interval:277491600)
> [ 87.829693] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.082 ns (step:128) - (measurement period time:0.280825239 sec time_interval:280825239) - (invoke count:10000000 tsc_interval:840869820)
> [ 87.942860] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.387 ns (step:128) - (measurement period time:0.103871104 sec time_interval:103871104) - (invoke count:10000000 tsc_interval:311019150)
> [ 88.242686] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.101 ns (step:158) - (measurement period time:0.281012946 sec time_interval:281012946) - (invoke count:9999978 tsc_interval:841431990)
> [ 88.354683] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.852 ns (step:158) - (measurement period time:0.098524040 sec time_interval:98524040) - (invoke count:9999978 tsc_interval:295008030)
> [ 88.655671] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.946 ns (step:250) - (measurement period time:0.289463793 sec time_interval:289463793) - (invoke count:10000000 tsc_interval:866736720)
> [ 88.776655] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.695 ns (step:250) - (measurement period time:0.106953355 sec time_interval:106953355) - (invoke count:10000000 tsc_interval:320247930)
>
> [ 100.068788] time_bench: Type:for_loop Per elem: 4 cycles(tsc) 1.567 ns (step:0) - (measurement period time:0.156710185 sec time_interval:156710185) - (invoke count:100000000 tsc_interval:469233480)
> [ 100.654304] time_bench: Type:kmem fastpath reuse Per elem: 170 cycles(tsc) 56.967 ns (step:0) - (measurement period time:0.569671924 sec time_interval:569671924) - (invoke count:10000000 tsc_interval:1705759620)
> [ 101.373300] time_bench: Type:kmem bulk_fallback Per elem: 212 cycles(tsc) 70.812 ns (step:1) - (measurement period time:0.708129741 sec time_interval:708129741) - (invoke count:10000000 tsc_interval:2120342250)
> [ 101.840283] time_bench: Type:kmem bulk_quick_reuse Per elem: 136 cycles(tsc) 45.527 ns (step:1) - (measurement period time:0.455275848 sec time_interval:455275848) - (invoke count:10000000 tsc_interval:1363225020)
> [ 102.139276] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 29.044 ns (step:2) - (measurement period time:0.290446762 sec time_interval:290446762) - (invoke count:10000000 tsc_interval:869680110)
> [ 102.303272] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.383 ns (step:2) - (measurement period time:0.153838537 sec time_interval:153838537) - (invoke count:10000000 tsc_interval:460636140)
> [ 103.012346] time_bench: Type:kmem bulk_fallback Per elem: 209 cycles(tsc) 69.979 ns (step:3) - (measurement period time:0.699793666 sec time_interval:699793666) - (invoke count:9999999 tsc_interval:2095381860)
> [ 103.148352] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.208 ns (step:3) - (measurement period time:0.132082868 sec time_interval:132082868) - (invoke count:9999999 tsc_interval:395493210)
> [ 103.462233] time_bench: Type:kmem bulk_fallback Per elem: 91 cycles(tsc) 30.467 ns (step:4) - (measurement period time:0.304675759 sec time_interval:304675759) - (invoke count:10000000 tsc_interval:912285930)
> [ 103.761428] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.059 ns (step:4) - (measurement period time:0.290597158 sec time_interval:290597158) - (invoke count:10000000 tsc_interval:870129780)
> [ 104.501334] time_bench: Type:kmem bulk_fallback Per elem: 218 cycles(tsc) 73.076 ns (step:8) - (measurement period time:0.730767822 sec time_interval:730767822) - (invoke count:10000000 tsc_interval:2188127310)
> [ 104.732329] time_bench: Type:kmem bulk_quick_reuse Per elem: 66 cycles(tsc) 22.280 ns (step:8) - (measurement period time:0.222806934 sec time_interval:222806934) - (invoke count:10000000 tsc_interval:667146780)
> [ 105.346195] time_bench: Type:kmem bulk_fallback Per elem: 180 cycles(tsc) 60.308 ns (step:16) - (measurement period time:0.603085855 sec time_interval:603085855) - (invoke count:10000000 tsc_interval:1805810910)
> [ 105.565213] time_bench: Type:kmem bulk_quick_reuse Per elem: 62 cycles(tsc) 20.731 ns (step:16) - (measurement period time:0.207317878 sec time_interval:207317878) - (invoke count:10000000 tsc_interval:620768190)
> [ 106.154163] time_bench: Type:kmem bulk_fallback Per elem: 173 cycles(tsc) 57.884 ns (step:30) - (measurement period time:0.578841035 sec time_interval:578841035) - (invoke count:9999990 tsc_interval:1733213910)
> [ 106.450218] time_bench: Type:kmem bulk_quick_reuse Per elem: 85 cycles(tsc) 28.455 ns (step:30) - (measurement period time:0.284558769 sec time_interval:284558769) - (invoke count:9999990 tsc_interval:852048780)
> [ 107.137140] time_bench: Type:kmem bulk_fallback Per elem: 199 cycles(tsc) 66.729 ns (step:32) - (measurement period time:0.667298185 sec time_interval:667298185) - (invoke count:10000000 tsc_interval:1998081120)
> [ 107.244232] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.655 ns (step:32) - (measurement period time:0.096558958 sec time_interval:96558958) - (invoke count:10000000 tsc_interval:289124430)
> [ 107.528225] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.584 ns (step:34) - (measurement period time:0.275841028 sec time_interval:275841028) - (invoke count:9999978 tsc_interval:825940800)
> [ 107.628207] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.182 ns (step:34) - (measurement period time:0.091822659 sec time_interval:91822659) - (invoke count:9999978 tsc_interval:274942830)
> [ 107.913114] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.639 ns (step:48) - (measurement period time:0.276397658 sec time_interval:276397658) - (invoke count:9999984 tsc_interval:827612400)
> [ 108.013118] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.281 ns (step:48) - (measurement period time:0.092811773 sec time_interval:92811773) - (invoke count:9999984 tsc_interval:277904550)
> [ 108.293222] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.413 ns (step:64) - (measurement period time:0.274134107 sec time_interval:274134107) - (invoke count:10000000 tsc_interval:820835190)
> [ 108.394122] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.252 ns (step:64) - (measurement period time:0.092524305 sec time_interval:92524305) - (invoke count:10000000 tsc_interval:277043580)
> [ 109.015115] time_bench: Type:kmem bulk_fallback Per elem: 183 cycles(tsc) 61.171 ns (step:128) - (measurement period time:0.611713784 sec time_interval:611713784) - (invoke count:10000000 tsc_interval:1831645590)
> [ 109.282175] time_bench: Type:kmem bulk_quick_reuse Per elem: 76 cycles(tsc) 25.538 ns (step:128) - (measurement period time:0.255382498 sec time_interval:255382498) - (invoke count:10000000 tsc_interval:764687130)
> [ 109.898178] time_bench: Type:kmem bulk_fallback Per elem: 181 cycles(tsc) 60.732 ns (step:158) - (measurement period time:0.607324486 sec time_interval:607324486) - (invoke count:9999978 tsc_interval:1818501990)
> [ 110.111052] time_bench: Type:kmem bulk_quick_reuse Per elem: 60 cycles(tsc) 20.241 ns (step:158) - (measurement period time:0.202414120 sec time_interval:202414120) - (invoke count:9999978 tsc_interval:606085230)
> [ 110.715034] time_bench: Type:kmem bulk_fallback Per elem: 178 cycles(tsc) 59.483 ns (step:250) - (measurement period time:0.594833299 sec time_interval:594833299) - (invoke count:10000000 tsc_interval:1781100600)
> [ 110.974129] time_bench: Type:kmem bulk_quick_reuse Per elem: 75 cycles(tsc) 25.167 ns (step:250) - (measurement period time:0.251679547 sec time_interval:251679547) - (invoke count:10000000 tsc_interval:753599310)
>
> [ 111.856730] time_bench: Type:for_loop Per elem: 4 cycles(tsc) 1.349 ns (step:0) - (measurement period time:0.134993630 sec time_interval:134993630) - (invoke count:100000000 tsc_interval:404208090)
> [ 112.407098] time_bench: Type:kmem fastpath reuse Per elem: 159 cycles(tsc) 53.400 ns (step:0) - (measurement period time:0.534001917 sec time_interval:534001917) - (invoke count:10000000 tsc_interval:1598953680)
> [ 113.150981] time_bench: Type:kmem bulk_fallback Per elem: 216 cycles(tsc) 72.396 ns (step:1) - (measurement period time:0.723960939 sec time_interval:723960939) - (invoke count:10000000 tsc_interval:2167744650)
> [ 113.381971] time_bench: Type:kmem bulk_quick_reuse Per elem: 67 cycles(tsc) 22.501 ns (step:1) - (measurement period time:0.225017504 sec time_interval:225017504) - (invoke count:10000000 tsc_interval:673765620)
> [ 113.681963] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.967 ns (step:2) - (measurement period time:0.289671345 sec time_interval:289671345) - (invoke count:10000000 tsc_interval:867358230)
> [ 113.843955] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.643 ns (step:2) - (measurement period time:0.156437917 sec time_interval:156437917) - (invoke count:10000000 tsc_interval:468418740)
> [ 114.140953] time_bench: Type:kmem bulk_fallback Per elem: 85 cycles(tsc) 28.414 ns (step:3) - (measurement period time:0.284148848 sec time_interval:284148848) - (invoke count:9999999 tsc_interval:850821930)
> [ 114.279933] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.207 ns (step:3) - (measurement period time:0.132073229 sec time_interval:132073229) - (invoke count:9999999 tsc_interval:395463870)
> [ 114.609120] time_bench: Type:kmem bulk_fallback Per elem: 93 cycles(tsc) 31.197 ns (step:4) - (measurement period time:0.311972955 sec time_interval:311972955) - (invoke count:10000000 tsc_interval:934136040)
> [ 114.909950] time_bench: Type:kmem bulk_quick_reuse Per elem: 87 cycles(tsc) 29.326 ns (step:4) - (measurement period time:0.293267093 sec time_interval:293267093) - (invoke count:10000000 tsc_interval:878124330)
> [ 115.622058] time_bench: Type:kmem bulk_fallback Per elem: 209 cycles(tsc) 70.083 ns (step:8) - (measurement period time:0.700833456 sec time_interval:700833456) - (invoke count:10000000 tsc_interval:2098495740)
> [ 115.729918] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.072 ns (step:8) - (measurement period time:0.100729060 sec time_interval:100729060) - (invoke count:10000000 tsc_interval:301610850)
> [ 116.445890] time_bench: Type:kmem bulk_fallback Per elem: 211 cycles(tsc) 70.512 ns (step:16) - (measurement period time:0.705126903 sec time_interval:705126903) - (invoke count:10000000 tsc_interval:2111350800)
> [ 116.597986] time_bench: Type:kmem bulk_quick_reuse Per elem: 43 cycles(tsc) 14.451 ns (step:16) - (measurement period time:0.144517256 sec time_interval:144517256) - (invoke count:10000000 tsc_interval:432725340)
> [ 117.293842] time_bench: Type:kmem bulk_fallback Per elem: 205 cycles(tsc) 68.660 ns (step:30) - (measurement period time:0.686602607 sec time_interval:686602607) - (invoke count:9999990 tsc_interval:2055883860)
> [ 117.513834] time_bench: Type:kmem bulk_quick_reuse Per elem: 65 cycles(tsc) 21.724 ns (step:30) - (measurement period time:0.217241306 sec time_interval:217241306) - (invoke count:9999990 tsc_interval:650481120)
> [ 118.157816] time_bench: Type:kmem bulk_fallback Per elem: 189 cycles(tsc) 63.344 ns (step:32) - (measurement period time:0.633443044 sec time_interval:633443044) - (invoke count:10000000 tsc_interval:1896708780)
> [ 118.380992] time_bench: Type:kmem bulk_quick_reuse Per elem: 64 cycles(tsc) 21.381 ns (step:32) - (measurement period time:0.213815392 sec time_interval:213815392) - (invoke count:10000000 tsc_interval:640223670)
> [ 118.981808] time_bench: Type:kmem bulk_fallback Per elem: 176 cycles(tsc) 58.885 ns (step:34) - (measurement period time:0.588855917 sec time_interval:588855917) - (invoke count:9999978 tsc_interval:1763201640)
> [ 119.078787] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.191 ns (step:34) - (measurement period time:0.091919103 sec time_interval:91919103) - (invoke count:9999978 tsc_interval:275231340)
> [ 119.368789] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.533 ns (step:48) - (measurement period time:0.275334132 sec time_interval:275334132) - (invoke count:9999984 tsc_interval:824428110)
> [ 119.471780] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.519 ns (step:48) - (measurement period time:0.095195091 sec time_interval:95195091) - (invoke count:9999984 tsc_interval:285040080)
> [ 119.775775] time_bench: Type:kmem bulk_fallback Per elem: 87 cycles(tsc) 29.149 ns (step:64) - (measurement period time:0.291498274 sec time_interval:291498274) - (invoke count:10000000 tsc_interval:872828640)
> [ 119.896771] time_bench: Type:kmem bulk_quick_reuse Per elem: 33 cycles(tsc) 11.330 ns (step:64) - (measurement period time:0.113304207 sec time_interval:113304207) - (invoke count:10000000 tsc_interval:339264000)
> [ 120.199773] time_bench: Type:kmem bulk_fallback Per elem: 87 cycles(tsc) 29.289 ns (step:128) - (measurement period time:0.292891157 sec time_interval:292891157) - (invoke count:10000000 tsc_interval:876999360)
> [ 120.320757] time_bench: Type:kmem bulk_quick_reuse Per elem: 34 cycles(tsc) 11.476 ns (step:128) - (measurement period time:0.114763286 sec time_interval:114763286) - (invoke count:10000000 tsc_interval:343632900)
> [ 120.976762] time_bench: Type:kmem bulk_fallback Per elem: 192 cycles(tsc) 64.320 ns (step:158) - (measurement period time:0.643207519 sec time_interval:643207519) - (invoke count:9999978 tsc_interval:1925946840)
> [ 121.231790] time_bench: Type:kmem bulk_quick_reuse Per elem: 73 cycles(tsc) 24.705 ns (step:158) - (measurement period time:0.247055281 sec time_interval:247055281) - (invoke count:9999978 tsc_interval:739752480)
> [ 121.875817] time_bench: Type:kmem bulk_fallback Per elem: 189 cycles(tsc) 63.224 ns (step:250) - (measurement period time:0.632244442 sec time_interval:632244442) - (invoke count:10000000 tsc_interval:1893119520)
> [ 122.148737] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.410 ns (step:250) - (measurement period time:0.264101742 sec time_interval:264101742) - (invoke count:10000000 tsc_interval:790794030)
>
> Patched:
>
> [ 654.054203] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.776 ns (step:0) - (measurement period time:0.077664118 sec time_interval:77664118) - (invoke count:100000000 tsc_interval:232545750)
> [ 654.592857] time_bench: Type:kmem fastpath reuse Per elem: 161 cycles(tsc) 53.860 ns (step:0) - (measurement period time:0.538607021 sec time_interval:538607021) - (invoke count:10000000 tsc_interval:1612734660)
> [ 655.248550] time_bench: Type:kmem bulk_fallback Per elem: 196 cycles(tsc) 65.568 ns (step:1) - (measurement period time:0.655680061 sec time_interval:655680061) - (invoke count:10000000 tsc_interval:1963282620)
> [ 655.475563] time_bench: Type:kmem bulk_quick_reuse Per elem: 67 cycles(tsc) 22.697 ns (step:1) - (measurement period time:0.226975586 sec time_interval:226975586) - (invoke count:10000000 tsc_interval:679625070)
> [ 655.757615] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.204 ns (step:2) - (measurement period time:0.282047104 sec time_interval:282047104) - (invoke count:10000000 tsc_interval:844524090)
> [ 655.943657] time_bench: Type:kmem bulk_quick_reuse Per elem: 55 cycles(tsc) 18.599 ns (step:2) - (measurement period time:0.185992389 sec time_interval:185992389) - (invoke count:10000000 tsc_interval:556910100)
> [ 656.221528] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.783 ns (step:3) - (measurement period time:0.277833288 sec time_interval:277833288) - (invoke count:9999999 tsc_interval:831906840)
> [ 656.535062] time_bench: Type:kmem bulk_quick_reuse Per elem: 93 cycles(tsc) 31.351 ns (step:3) - (measurement period time:0.313512217 sec time_interval:313512217) - (invoke count:9999999 tsc_interval:938739120)
> [ 656.843267] time_bench: Type:kmem bulk_fallback Per elem: 92 cycles(tsc) 30.818 ns (step:4) - (measurement period time:0.308185034 sec time_interval:308185034) - (invoke count:10000000 tsc_interval:922788240)
> [ 656.961808] time_bench: Type:kmem bulk_quick_reuse Per elem: 35 cycles(tsc) 11.850 ns (step:4) - (measurement period time:0.118503561 sec time_interval:118503561) - (invoke count:10000000 tsc_interval:354830820)
> [ 657.691366] time_bench: Type:kmem bulk_fallback Per elem: 218 cycles(tsc) 72.954 ns (step:8) - (measurement period time:0.729541418 sec time_interval:729541418) - (invoke count:10000000 tsc_interval:2184443100)
> [ 657.792001] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.060 ns (step:8) - (measurement period time:0.100604744 sec time_interval:100604744) - (invoke count:10000000 tsc_interval:301236990)
> [ 658.070712] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.868 ns (step:16) - (measurement period time:0.278687720 sec time_interval:278687720) - (invoke count:10000000 tsc_interval:834465960)
> [ 658.169621] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.887 ns (step:16) - (measurement period time:0.098871033 sec time_interval:98871033) - (invoke count:10000000 tsc_interval:296045940)
> [ 658.846891] time_bench: Type:kmem bulk_fallback Per elem: 202 cycles(tsc) 67.726 ns (step:30) - (measurement period time:0.677260248 sec time_interval:677260248) - (invoke count:9999990 tsc_interval:2027899590)
> [ 658.940547] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.354 ns (step:30) - (measurement period time:0.093547668 sec time_interval:93547668) - (invoke count:9999990 tsc_interval:280105560)
> [ 659.214131] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.356 ns (step:32) - (measurement period time:0.273564878 sec time_interval:273564878) - (invoke count:10000000 tsc_interval:819126750)
> [ 659.307010] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.286 ns (step:32) - (measurement period time:0.092862249 sec time_interval:92862249) - (invoke count:10000000 tsc_interval:278053470)
> [ 659.577675] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.065 ns (step:34) - (measurement period time:0.270657877 sec time_interval:270657877) - (invoke count:9999978 tsc_interval:810422340)
> [ 659.670155] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.246 ns (step:34) - (measurement period time:0.092468447 sec time_interval:92468447) - (invoke count:9999978 tsc_interval:276874410)
> [ 659.941498] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.129 ns (step:48) - (measurement period time:0.271292799 sec time_interval:271292799) - (invoke count:9999984 tsc_interval:812323620)
> [ 660.034358] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.284 ns (step:48) - (measurement period time:0.092846689 sec time_interval:92846689) - (invoke count:9999984 tsc_interval:278007390)
> [ 660.305652] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.125 ns (step:64) - (measurement period time:0.271257793 sec time_interval:271257793) - (invoke count:10000000 tsc_interval:812218680)
> [ 660.535235] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 22.955 ns (step:64) - (measurement period time:0.229550122 sec time_interval:229550122) - (invoke count:10000000 tsc_interval:687333360)
> [ 660.814888] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.964 ns (step:128) - (measurement period time:0.279643666 sec time_interval:279643666) - (invoke count:10000000 tsc_interval:837328200)
> [ 660.915969] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.104 ns (step:128) - (measurement period time:0.101047589 sec time_interval:101047589) - (invoke count:10000000 tsc_interval:302562990)
> [ 661.275325] time_bench: Type:kmem bulk_fallback Per elem: 107 cycles(tsc) 35.933 ns (step:158) - (measurement period time:0.359338210 sec time_interval:359338210) - (invoke count:9999978 tsc_interval:1075954290)
> [ 661.375091] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.975 ns (step:158) - (measurement period time:0.099750172 sec time_interval:99750172) - (invoke count:9999978 tsc_interval:298678200)
> [ 661.655844] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.074 ns (step:250) - (measurement period time:0.280746521 sec time_interval:280746521) - (invoke count:10000000 tsc_interval:840630900)
> [ 661.762658] time_bench: Type:kmem bulk_quick_reuse Per elem: 31 cycles(tsc) 10.680 ns (step:250) - (measurement period time:0.106802018 sec time_interval:106802018) - (invoke count:10000000 tsc_interval:319793460)
>
> [ 663.188701] time_bench: Type:for_loop Per elem: 2 cycles(tsc) 0.772 ns (step:0) - (measurement period time:0.077219119 sec time_interval:77219119) - (invoke count:100000000 tsc_interval:231214350)
> [ 663.723737] time_bench: Type:kmem fastpath reuse Per elem: 160 cycles(tsc) 53.501 ns (step:0) - (measurement period time:0.535016285 sec time_interval:535016285) - (invoke count:10000000 tsc_interval:1601983200)
> [ 664.022069] time_bench: Type:kmem bulk_fallback Per elem: 89 cycles(tsc) 29.828 ns (step:1) - (measurement period time:0.298280101 sec time_interval:298280101) - (invoke count:10000000 tsc_interval:893130450)
> [ 664.248849] time_bench: Type:kmem bulk_quick_reuse Per elem: 67 cycles(tsc) 22.677 ns (step:1) - (measurement period time:0.226775284 sec time_interval:226775284) - (invoke count:10000000 tsc_interval:679026090)
> [ 664.530649] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.179 ns (step:2) - (measurement period time:0.281793671 sec time_interval:281793671) - (invoke count:10000000 tsc_interval:843766020)
> [ 664.686627] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.593 ns (step:2) - (measurement period time:0.155939154 sec time_interval:155939154) - (invoke count:10000000 tsc_interval:466923720)
> [ 665.370321] time_bench: Type:kmem bulk_fallback Per elem: 204 cycles(tsc) 68.367 ns (step:3) - (measurement period time:0.683678844 sec time_interval:683678844) - (invoke count:9999999 tsc_interval:2047118220)
> [ 665.685507] time_bench: Type:kmem bulk_quick_reuse Per elem: 94 cycles(tsc) 31.513 ns (step:3) - (measurement period time:0.315139143 sec time_interval:315139143) - (invoke count:9999999 tsc_interval:943611060)
> [ 666.448847] time_bench: Type:kmem bulk_fallback Per elem: 228 cycles(tsc) 76.331 ns (step:4) - (measurement period time:0.763310680 sec time_interval:763310680) - (invoke count:10000000 tsc_interval:2285557860)
> [ 666.745314] time_bench: Type:kmem bulk_quick_reuse Per elem: 88 cycles(tsc) 29.643 ns (step:4) - (measurement period time:0.296436791 sec time_interval:296436791) - (invoke count:10000000 tsc_interval:887610960)
> [ 667.041829] time_bench: Type:kmem bulk_fallback Per elem: 88 cycles(tsc) 29.650 ns (step:8) - (measurement period time:0.296505592 sec time_interval:296505592) - (invoke count:10000000 tsc_interval:887817120)
> [ 667.142484] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.064 ns (step:8) - (measurement period time:0.100642315 sec time_interval:100642315) - (invoke count:10000000 tsc_interval:301350000)
> [ 667.420593] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.810 ns (step:16) - (measurement period time:0.278104977 sec time_interval:278104977) - (invoke count:10000000 tsc_interval:832721010)
> [ 667.519271] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.866 ns (step:16) - (measurement period time:0.098662815 sec time_interval:98662815) - (invoke count:10000000 tsc_interval:295422450)
> [ 667.792475] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.315 ns (step:30) - (measurement period time:0.273152701 sec time_interval:273152701) - (invoke count:9999990 tsc_interval:817892820)
> [ 668.023804] time_bench: Type:kmem bulk_quick_reuse Per elem: 69 cycles(tsc) 23.130 ns (step:30) - (measurement period time:0.231303811 sec time_interval:231303811) - (invoke count:9999990 tsc_interval:692584950)
> [ 668.696907] time_bench: Type:kmem bulk_fallback Per elem: 201 cycles(tsc) 67.306 ns (step:32) - (measurement period time:0.673067682 sec time_interval:673067682) - (invoke count:10000000 tsc_interval:2015345790)
> [ 668.889019] time_bench: Type:kmem bulk_quick_reuse Per elem: 57 cycles(tsc) 19.208 ns (step:32) - (measurement period time:0.192088279 sec time_interval:192088279) - (invoke count:10000000 tsc_interval:575162820)
> [ 669.342870] time_bench: Type:kmem bulk_fallback Per elem: 135 cycles(tsc) 45.383 ns (step:34) - (measurement period time:0.453831353 sec time_interval:453831353) - (invoke count:9999978 tsc_interval:1358892420)
> [ 669.436107] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.322 ns (step:34) - (measurement period time:0.093220843 sec time_interval:93220843) - (invoke count:9999978 tsc_interval:279126840)
> [ 669.707772] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.165 ns (step:48) - (measurement period time:0.271654970 sec time_interval:271654970) - (invoke count:9999984 tsc_interval:813407310)
> [ 669.800509] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.268 ns (step:48) - (measurement period time:0.092683978 sec time_interval:92683978) - (invoke count:9999984 tsc_interval:277520190)
> [ 670.068757] time_bench: Type:kmem bulk_fallback Per elem: 80 cycles(tsc) 26.823 ns (step:64) - (measurement period time:0.268231313 sec time_interval:268231313) - (invoke count:10000000 tsc_interval:803156580)
> [ 670.297078] time_bench: Type:kmem bulk_quick_reuse Per elem: 68 cycles(tsc) 22.829 ns (step:64) - (measurement period time:0.228295958 sec time_interval:228295958) - (invoke count:10000000 tsc_interval:683578080)
> [ 670.573819] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.673 ns (step:128) - (measurement period time:0.276731254 sec time_interval:276731254) - (invoke count:10000000 tsc_interval:828607050)
> [ 670.676864] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.300 ns (step:128) - (measurement period time:0.103002111 sec time_interval:103002111) - (invoke count:10000000 tsc_interval:308415540)
> [ 671.318177] time_bench: Type:kmem bulk_fallback Per elem: 192 cycles(tsc) 64.130 ns (step:158) - (measurement period time:0.641303389 sec time_interval:641303389) - (invoke count:9999978 tsc_interval:1920234600)
> [ 671.417083] time_bench: Type:kmem bulk_quick_reuse Per elem: 29 cycles(tsc) 9.889 ns (step:158) - (measurement period time:0.098890269 sec time_interval:98890269) - (invoke count:9999978 tsc_interval:296103210)
> [ 671.700461] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.334 ns (step:250) - (measurement period time:0.283346426 sec time_interval:283346426) - (invoke count:10000000 tsc_interval:848415660)
> [ 671.965515] time_bench: Type:kmem bulk_quick_reuse Per elem: 79 cycles(tsc) 26.502 ns (step:250) - (measurement period time:0.265021064 sec time_interval:265021064) - (invoke count:10000000 tsc_interval:793543500)
>
> [ 686.749446] time_bench: Type:for_loop Per elem: 1 cycles(tsc) 0.660 ns (step:0) - (measurement period time:0.066028480 sec time_interval:66028480) - (invoke count:100000000 tsc_interval:197707140)
> [ 687.296902] time_bench: Type:kmem fastpath reuse Per elem: 163 cycles(tsc) 54.742 ns (step:0) - (measurement period time:0.547423736 sec time_interval:547423736) - (invoke count:10000000 tsc_interval:1639141260)
> [ 687.910620] time_bench: Type:kmem bulk_fallback Per elem: 183 cycles(tsc) 61.369 ns (step:1) - (measurement period time:0.613692564 sec time_interval:613692564) - (invoke count:10000000 tsc_interval:1837568160)
> [ 688.381090] time_bench: Type:kmem bulk_quick_reuse Per elem: 140 cycles(tsc) 47.045 ns (step:1) - (measurement period time:0.470452576 sec time_interval:470452576) - (invoke count:10000000 tsc_interval:1408667550)
> [ 688.662045] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.094 ns (step:2) - (measurement period time:0.280943997 sec time_interval:280943997) - (invoke count:10000000 tsc_interval:841225230)
> [ 688.817464] time_bench: Type:kmem bulk_quick_reuse Per elem: 46 cycles(tsc) 15.540 ns (step:2) - (measurement period time:0.155409002 sec time_interval:155409002) - (invoke count:10000000 tsc_interval:465337980)
> [ 689.094749] time_bench: Type:kmem bulk_fallback Per elem: 83 cycles(tsc) 27.723 ns (step:3) - (measurement period time:0.277235751 sec time_interval:277235751) - (invoke count:9999999 tsc_interval:830122170)
> [ 689.225706] time_bench: Type:kmem bulk_quick_reuse Per elem: 39 cycles(tsc) 13.091 ns (step:3) - (measurement period time:0.130919113 sec time_interval:130919113) - (invoke count:9999999 tsc_interval:392008440)
> [ 689.988861] time_bench: Type:kmem bulk_fallback Per elem: 228 cycles(tsc) 76.314 ns (step:4) - (measurement period time:0.763146670 sec time_interval:763146670) - (invoke count:10000000 tsc_interval:2285076870)
> [ 690.274210] time_bench: Type:kmem bulk_quick_reuse Per elem: 85 cycles(tsc) 28.532 ns (step:4) - (measurement period time:0.285320525 sec time_interval:285320525) - (invoke count:10000000 tsc_interval:854329500)
> [ 690.862234] time_bench: Type:kmem bulk_fallback Per elem: 176 cycles(tsc) 58.799 ns (step:8) - (measurement period time:0.587998540 sec time_interval:587998540) - (invoke count:10000000 tsc_interval:1760633010)
> [ 690.964020] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.171 ns (step:8) - (measurement period time:0.101718599 sec time_interval:101718599) - (invoke count:10000000 tsc_interval:304573500)
> [ 691.245251] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.122 ns (step:16) - (measurement period time:0.281223369 sec time_interval:281223369) - (invoke count:10000000 tsc_interval:842060850)
> [ 691.341256] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.599 ns (step:16) - (measurement period time:0.095990014 sec time_interval:95990014) - (invoke count:10000000 tsc_interval:287420100)
> [ 691.616379] time_bench: Type:kmem bulk_fallback Per elem: 82 cycles(tsc) 27.511 ns (step:30) - (measurement period time:0.275116534 sec time_interval:275116534) - (invoke count:9999990 tsc_interval:823776390)
> [ 691.710275] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.388 ns (step:30) - (measurement period time:0.093884613 sec time_interval:93884613) - (invoke count:9999990 tsc_interval:281115990)
> [ 691.982082] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.180 ns (step:32) - (measurement period time:0.271800767 sec time_interval:271800767) - (invoke count:10000000 tsc_interval:813847530)
> [ 692.077384] time_bench: Type:kmem bulk_quick_reuse Per elem: 28 cycles(tsc) 9.526 ns (step:32) - (measurement period time:0.095266005 sec time_interval:95266005) - (invoke count:10000000 tsc_interval:285252780)
> [ 692.348422] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.102 ns (step:34) - (measurement period time:0.271026511 sec time_interval:271026511) - (invoke count:9999978 tsc_interval:811529490)
> [ 692.440805] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.236 ns (step:34) - (measurement period time:0.092368535 sec time_interval:92368535) - (invoke count:9999978 tsc_interval:276576810)
> [ 692.712439] time_bench: Type:kmem bulk_fallback Per elem: 81 cycles(tsc) 27.162 ns (step:48) - (measurement period time:0.271619761 sec time_interval:271619761) - (invoke count:9999984 tsc_interval:813305970)
> [ 692.945558] time_bench: Type:kmem bulk_quick_reuse Per elem: 69 cycles(tsc) 23.309 ns (step:48) - (measurement period time:0.233091977 sec time_interval:233091977) - (invoke count:9999984 tsc_interval:697942470)
> [ 693.234591] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.902 ns (step:64) - (measurement period time:0.289021416 sec time_interval:289021416) - (invoke count:10000000 tsc_interval:865411350)
> [ 693.326142] time_bench: Type:kmem bulk_quick_reuse Per elem: 27 cycles(tsc) 9.153 ns (step:64) - (measurement period time:0.091539475 sec time_interval:91539475) - (invoke count:10000000 tsc_interval:274094220)
> [ 693.615858] time_bench: Type:kmem bulk_fallback Per elem: 86 cycles(tsc) 28.970 ns (step:128) - (measurement period time:0.289709207 sec time_interval:289709207) - (invoke count:10000000 tsc_interval:867470400)
> [ 693.717321] time_bench: Type:kmem bulk_quick_reuse Per elem: 30 cycles(tsc) 10.145 ns (step:128) - (measurement period time:0.101451019 sec time_interval:101451019) - (invoke count:10000000 tsc_interval:303772410)
> [ 694.000375] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.304 ns (step:158) - (measurement period time:0.283047625 sec time_interval:283047625) - (invoke count:9999978 tsc_interval:847523850)
> [ 694.108588] time_bench: Type:kmem bulk_quick_reuse Per elem: 32 cycles(tsc) 10.816 ns (step:158) - (measurement period time:0.108168257 sec time_interval:108168257) - (invoke count:9999978 tsc_interval:323885820)
> [ 694.392070] time_bench: Type:kmem bulk_fallback Per elem: 84 cycles(tsc) 28.344 ns (step:250) - (measurement period time:0.283447055 sec time_interval:283447055) - (invoke count:10000000 tsc_interval:848719800)
> [ 694.655226] time_bench: Type:kmem bulk_quick_reuse Per elem: 78 cycles(tsc) 26.312 ns (step:250) - (measurement period time:0.263123465 sec time_interval:263123465) - (invoke count:10000000 tsc_interval:787864230)
>
On Thu, Jun 18, 2020 at 12:27:07PM +0300, Mike Rapoport wrote:
> Hi Roman,
>
> On Mon, Jun 08, 2020 at 04:06:35PM -0700, Roman Gushchin wrote:
> > This is v6 of the slab cgroup controller rework.
> >
> > The patchset moves the accounting from the page level to the object
> > level. It allows to share slab pages between memory cgroups.
> > This leads to a significant win in the slab utilization (up to 45%)
> > and the corresponding drop in the total kernel memory footprint.
> > The reduced number of unmovable slab pages should also have a positive
> > effect on the memory fragmentation.
>
> ...
>
> > Johannes Weiner (1):
> > mm: memcontrol: decouple reference counting from page accounting
> >
> > Roman Gushchin (18):
> > mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state()
> > mm: memcg: prepare for byte-sized vmstat items
> > mm: memcg: convert vmstat slab counters to bytes
> > mm: slub: implement SLUB version of obj_to_index()
> > mm: memcg/slab: obj_cgroup API
> > mm: memcg/slab: allocate obj_cgroups for non-root slab pages
> > mm: memcg/slab: save obj_cgroup for non-root slab objects
> > mm: memcg/slab: charge individual slab objects instead of pages
> > mm: memcg/slab: deprecate memory.kmem.slabinfo
> > mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h
> > mm: memcg/slab: use a single set of kmem_caches for all accounted allocations
> > mm: memcg/slab: simplify memcg cache creation
> > mm: memcg/slab: remove memcg_kmem_get_cache()
> > mm: memcg/slab: deprecate slab_root_caches
> > mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo()
> > mm: memcg/slab: use a single set of kmem_caches for all allocations
> > kselftests: cgroup: add kernel memory accounting tests
> > tools/cgroup: add memcg_slabinfo.py tool
>
> Sorry for jumping late, but I'm really missing
>
> Documentation/vm/cgroup-slab.rst | < lots of + >
>
> in this series ;-)
Hi Mike!
That's a good point. I'll write something and send a separate patch.
Changes are barely visible to a user, so no rush here,
but it's definitely a good idea to document the new design.
Thank you!
On Thu, Jun 18, 2020 at 10:43:44AM +0200, Jesper Dangaard Brouer wrote:
> On Wed, 17 Jun 2020 18:29:28 -0700
> Roman Gushchin <[email protected]> wrote:
>
> > On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > > On 6/17/20 5:32 AM, Roman Gushchin wrote:
> > > > On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> > > >> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> > > >> >
> > > >> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > > >> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > > >> > > >
> > > >> [...]
> > > >> > >
> > > >> > > Have you performed any [perf] testing on SLAB with this patchset?
> > > >> >
> > > >> > The accounting part is the same for SLAB and SLUB, so there should be no
> > > >> > significant difference. I've checked that it compiles, boots and passes
> > > >> > kselftests. And that memory savings are there.
> > > >> >
> > > >>
> > > >> What about performance? Also you mentioned that sharing kmem-cache
> > > >> between accounted and non-accounted can have additional overhead. Any
> > > >> difference between SLAB and SLUB for such a case?
> > > >
> > > > Not really.
> > > >
> > > > Sharing a single set of caches adds some overhead to root- and non-accounted
> > > > allocations, which is something I've tried hard to avoid in my original version.
> > > > But I have to admit, it allows to simplify and remove a lot of code, and here
> > > > it's hard to argue with Johanness, who pushed on this design.
> > > >
> > > > With performance testing it's not that easy, because it's not obvious what
> > > > we wanna test. Obviously, per-object accounting is more expensive, and
> > > > measuring something like 1000000 allocations and deallocations in a line from
> > > > a single kmem_cache will show a regression. But in the real world the relative
> > > > cost of allocations is usually low, and we can get some benefits from a smaller
> > > > working set and from having shared kmem_cache objects cache hot.
> > > > Not speaking about some extra memory and the fragmentation reduction.
> > > >
> > > > We've done an extensive testing of the original version in Facebook production,
> > > > and we haven't noticed any regressions so far. But I have to admit, we were
> > > > using an original version with two sets of kmem_caches.
> > > >
> > > > If you have any specific tests in mind, I can definitely run them. Or if you
> > > > can help with the performance evaluation, I'll appreciate it a lot.
> > >
> > > Jesper provided some pointers here [1], it would be really great if you could
> > > run at least those microbenchmarks. With mmtests it's the major question of
> > > which subset/profiles to run, maybe the referenced commits provide some hints,
> > > or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
> > >
> > > [1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
> >
> > Oh, Jesper, I'm really sorry, somehow I missed your mail.
> > Thank you, Vlastimil, for pointing at it.
> >
> > I've got some results (slab_bulk_test01), but honestly I fail to interpret them.
> >
> > I ran original vs patched with SLUB and SLAB, each test several times and picked
> > 3 which looked most consistently. But it still looks very noisy.
> >
> > I ran them on my desktop (8-core Ryzen 1700, 16 GB RAM, Fedora 32),
> > it's 5.8-rc1 + slab controller v6 vs 5.8-rc1 (default config from Fedora 32).
>
> What about running these tests on the server level hardware, that you
> intent to run this on?
I'm going to backport this version to the kernel version we're using internally
and will come up with more number soon.
>
> >
> > How should I interpret this data?
>
> First of all these SLUB+SLAB microbenchmarks use object size 256 bytes,
> because network stack alloc object of this size for SKBs/sk_buff (due
> to cache-align as used size is 224 bytes). Checked SLUB: Each slab use
> 2 pages (8192 bytes) and contain 32 object of size 256 (256*32=8192).
>
> The SLUB allocator have a per-CPU slab which speedup fast-reuse, in this
> case up-to 32 objects. For SLUB the "fastpath reuse" test this behaviour,
> and it serves as a baseline for optimal 1-object performance (where my bulk
> API tries to beat that, which is possible even for 1-object due to knowing
> bulk API cannot be used from IRQ context).
>
> SLUB fastpath: 3 measurements reporting cycles(tsc)
> - SLUB-patched : fastpath reuse: 184 - 177 - 176 cycles(tsc)
> - SLUB-original: fastpath reuse: 178 - 153 - 156 cycles(tsc)
>
> There are some stability concerns as you mention, but it seems pretty
> consistently that patched version is slower. If you compile with
> no-PREEMPT you can likely get more stable results (and remove a slight
> overhead for SLUB fastpath).
>
> The microbenchmark also measures the bulk-API, which is AFAIK only used
> by network stack (and io_uring). I guess you shouldn't focus too much
> on these bulk measurements. When bulk-API cross this objects per slab
> threshold, or is unlucky is it use two per-CPU slab, then the
> measurements can fluctuate a bit.
>
> Your numbers for SLUB bulk-API:
>
> SLUB-patched - bulk-API
> - SLUB-patched : bulk_quick_reuse objects=1 : 187 - 90 - 224 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=2 : 110 - 53 - 133 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=3 : 88 - 95 - 42 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=4 : 91 - 85 - 36 cycles(tsc)
> - SLUB-patched : bulk_quick_reuse objects=8 : 32 - 66 - 32 cycles(tsc)
>
> SLUB-original - bulk-API
> - SLUB-original: bulk_quick_reuse objects=1 : 87 - 87 - 142 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=2 : 52 - 53 - 53 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=3 : 42 - 42 - 91 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=4 : 91 - 37 - 37 cycles(tsc)
> - SLUB-original: bulk_quick_reuse objects=8 : 31 - 79 - 76 cycles(tsc)
>
> Maybe it is just noise or instability in measurements, but it seem that the
> 1-object case is consistently slower in your patched version.
>
> Mail is too long now... I'll take a look at your SLAB results and followup.
Thank you very much for helping with the analysis!
So does it mean you're looking at the smallest number in each series?
If so, the difference is not that big?
Theoretically speaking it should get worse (especially for non-root allocations),
but if the difference is not big, it still should be better, because there is
a big expected win from memory savings/smaller working set/less fragmentation etc.
The only thing I'm slightly worried is what's the effect on root allocations
if we're sharing slab caches between root- and non-root allocations. Because if
someone depends so much on the allocation speed, memcg-based accounting can be
ignored anyway. For most users the cost of allocation is negligible.
That's why the patch which merges root- and memcg slab caches is put on top
and can be reverted if somebody will complain.
Thank you!
On Thu, Jun 18, 2020 at 11:31:21AM +0200, Jesper Dangaard Brouer wrote:
> On Thu, 18 Jun 2020 10:43:44 +0200
> Jesper Dangaard Brouer <[email protected]> wrote:
>
> > On Wed, 17 Jun 2020 18:29:28 -0700
> > Roman Gushchin <[email protected]> wrote:
> >
> > > On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > > > On 6/17/20 5:32 AM, Roman Gushchin wrote:
> > > > > On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> > > > >> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> > > > >> >
> > > > >> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > > > >> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > > > >> > > >
> > > > >> [...]
> > > > >> > >
> > > > >> > > Have you performed any [perf] testing on SLAB with this patchset?
> > > > >> >
> > > > >> > The accounting part is the same for SLAB and SLUB, so there should be no
> > > > >> > significant difference. I've checked that it compiles, boots and passes
> > > > >> > kselftests. And that memory savings are there.
> > > > >> >
> > > > >>
> > > > >> What about performance? Also you mentioned that sharing kmem-cache
> > > > >> between accounted and non-accounted can have additional overhead. Any
> > > > >> difference between SLAB and SLUB for such a case?
> > > > >
> > > > > Not really.
> > > > >
> > > > > Sharing a single set of caches adds some overhead to root- and non-accounted
> > > > > allocations, which is something I've tried hard to avoid in my original version.
> > > > > But I have to admit, it allows to simplify and remove a lot of code, and here
> > > > > it's hard to argue with Johanness, who pushed on this design.
> > > > >
> > > > > With performance testing it's not that easy, because it's not obvious what
> > > > > we wanna test. Obviously, per-object accounting is more expensive, and
> > > > > measuring something like 1000000 allocations and deallocations in a line from
> > > > > a single kmem_cache will show a regression. But in the real world the relative
> > > > > cost of allocations is usually low, and we can get some benefits from a smaller
> > > > > working set and from having shared kmem_cache objects cache hot.
> > > > > Not speaking about some extra memory and the fragmentation reduction.
> > > > >
> > > > > We've done an extensive testing of the original version in Facebook production,
> > > > > and we haven't noticed any regressions so far. But I have to admit, we were
> > > > > using an original version with two sets of kmem_caches.
> > > > >
> > > > > If you have any specific tests in mind, I can definitely run them. Or if you
> > > > > can help with the performance evaluation, I'll appreciate it a lot.
> > > >
> > > > Jesper provided some pointers here [1], it would be really great if you could
> > > > run at least those microbenchmarks. With mmtests it's the major question of
> > > > which subset/profiles to run, maybe the referenced commits provide some hints,
> > > > or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
> > > >
> > > > [1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
> > >
> > > Oh, Jesper, I'm really sorry, somehow I missed your mail.
> > > Thank you, Vlastimil, for pointing at it.
> > >
> > > I've got some results (slab_bulk_test01), but honestly I fail to interpret them.
> > >
> > > I ran original vs patched with SLUB and SLAB, each test several times and picked
> > > 3 which looked most consistently. But it still looks very noisy.
> > >
> > > I ran them on my desktop (8-core Ryzen 1700, 16 GB RAM, Fedora 32),
> > > it's 5.8-rc1 + slab controller v6 vs 5.8-rc1 (default config from Fedora 32).
> >
> > What about running these tests on the server level hardware, that you
> > intent to run this on?
>
> To give you an idea of the performance difference I ran the same test
> on a Broadwell Intel(R) Xeon(R) CPU E5-1650 v4 @ 3.60GHz.
>
> The SLUB fastpath:
> Type:kmem fastpath reuse Per elem: 60 cycles(tsc) 16.822 ns
>
>
> > >
> > > How should I interpret this data?
> >
> > First of all these SLUB+SLAB microbenchmarks use object size 256 bytes,
> > because network stack alloc object of this size for SKBs/sk_buff (due
> > to cache-align as used size is 224 bytes). Checked SLUB: Each slab use
> > 2 pages (8192 bytes) and contain 32 object of size 256 (256*32=8192).
> >
> > The SLUB allocator have a per-CPU slab which speedup fast-reuse, in this
> > case up-to 32 objects. For SLUB the "fastpath reuse" test this behaviour,
> > and it serves as a baseline for optimal 1-object performance (where my bulk
> > API tries to beat that, which is possible even for 1-object due to knowing
> > bulk API cannot be used from IRQ context).
> >
> > SLUB fastpath: 3 measurements reporting cycles(tsc)
> > - SLUB-patched : fastpath reuse: 184 - 177 - 176 cycles(tsc)
> > - SLUB-original: fastpath reuse: 178 - 153 - 156 cycles(tsc)
> >
>
> For your SLAB results:
>
> SLAB fastpath: 3 measurements reporting cycles(tsc)
> - SLAB-patched : 161 - 160 - 163 cycles(tsc)
> - SLAB-original: 174 - 170 - 159 cycles(tsc)
>
> I find it strange that SLAB is slightly better than SLUB (in many
> measurements), because SLUB should have an advantage on this fast-path
> quick reuse due to the per-CPU slabs. Maybe this is also related to
> the CPU arch you are using?
>
>
> > There are some stability concerns as you mention, but it seems pretty
> > consistently that patched version is slower. If you compile with
> > no-PREEMPT you can likely get more stable results (and remove a slight
> > overhead for SLUB fastpath).
> >
> > The microbenchmark also measures the bulk-API, which is AFAIK only used
> > by network stack (and io_uring). I guess you shouldn't focus too much
> > on these bulk measurements. When bulk-API cross this objects per slab
> > threshold, or is unlucky is it use two per-CPU slab, then the
> > measurements can fluctuate a bit.
> >
> > Your numbers for SLUB bulk-API:
> >
> > SLUB-patched - bulk-API
> > - SLUB-patched : bulk_quick_reuse objects=1 : 187 - 90 - 224 cycles(tsc)
> > - SLUB-patched : bulk_quick_reuse objects=2 : 110 - 53 - 133 cycles(tsc)
> > - SLUB-patched : bulk_quick_reuse objects=3 : 88 - 95 - 42 cycles(tsc)
> > - SLUB-patched : bulk_quick_reuse objects=4 : 91 - 85 - 36 cycles(tsc)
> > - SLUB-patched : bulk_quick_reuse objects=8 : 32 - 66 - 32 cycles(tsc)
> >
> > SLUB-original - bulk-API
> > - SLUB-original: bulk_quick_reuse objects=1 : 87 - 87 - 142 cycles(tsc)
> > - SLUB-original: bulk_quick_reuse objects=2 : 52 - 53 - 53 cycles(tsc)
> > - SLUB-original: bulk_quick_reuse objects=3 : 42 - 42 - 91 cycles(tsc)
> > - SLUB-original: bulk_quick_reuse objects=4 : 91 - 37 - 37 cycles(tsc)
> > - SLUB-original: bulk_quick_reuse objects=8 : 31 - 79 - 76 cycles(tsc)
>
> Your numbers for SLAB bulk-API:
>
> SLAB-patched - bulk-API
> - SLAB-patched : bulk_quick_reuse objects=1 : 67 - 67 - 140 cycles(tsc)
> - SLAB-patched : bulk_quick_reuse objects=2 : 55 - 46 - 46 cycles(tsc)
> - SLAB-patched : bulk_quick_reuse objects=3 : 93 - 94 - 39 cycles(tsc)
> - SLAB-patched : bulk_quick_reuse objects=4 : 35 - 88 - 85 cycles(tsc)
> - SLAB-patched : bulk_quick_reuse objects=8 : 30 - 30 - 30 cycles(tsc)
>
> SLAB-original- bulk-API
> - SLAB-original: bulk_quick_reuse objects=1 : 143 - 136 - 67 cycles(tsc)
> - SLAB-original: bulk_quick_reuse objects=2 : 45 - 46 - 46 cycles(tsc)
> - SLAB-original: bulk_quick_reuse objects=3 : 38 - 39 - 39 cycles(tsc)
> - SLAB-original: bulk_quick_reuse objects=4 : 35 - 87 - 87 cycles(tsc)
> - SLAB-original: bulk_quick_reuse objects=8 : 29 - 66 - 30 cycles(tsc)
>
> In case of SLAB I expect the bulk-API to be slightly faster than SLUB,
> as the SLUB bulk code is much more advanced.
So again it looks like a patched version is only slightly worse if we're taking
the smallest number in each series. Is it a correct assumption?
Thanks!
On Thu, 18 Jun 2020 18:27:12 -0700
Roman Gushchin <[email protected]> wrote:
> Theoretically speaking it should get worse (especially for non-root allocations),
> but if the difference is not big, it still should be better, because there is
> a big expected win from memory savings/smaller working set/less fragmentation etc.
>
> The only thing I'm slightly worried is what's the effect on root allocations
> if we're sharing slab caches between root- and non-root allocations. Because if
> someone depends so much on the allocation speed, memcg-based accounting can be
> ignored anyway. For most users the cost of allocation is negligible.
> That's why the patch which merges root- and memcg slab caches is put on top
> and can be reverted if somebody will complain.
In general I like this work for saving memory, but you also have to be
aware of the negative consequences of sharing slab caches. At Red Hat
we have experienced very hard to find kernel bugs, that point to memory
corruption at a completely wrong kernel code, because other kernel code
were corrupting the shared slab cache. (Hint a workaround is to enable
SLUB debugging to disable this sharing).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
On Thu, 18 Jun 2020 18:30:13 -0700
Roman Gushchin <[email protected]> wrote:
> On Thu, Jun 18, 2020 at 11:31:21AM +0200, Jesper Dangaard Brouer wrote:
> > On Thu, 18 Jun 2020 10:43:44 +0200
> > Jesper Dangaard Brouer <[email protected]> wrote:
> >
> > > On Wed, 17 Jun 2020 18:29:28 -0700
> > > Roman Gushchin <[email protected]> wrote:
> > >
> > > > On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > > > > On 6/17/20 5:32 AM, Roman Gushchin wrote:
> > > > > > On Tue, Jun 16, 2020 at 08:05:39PM -0700, Shakeel Butt wrote:
> > > > > >> On Tue, Jun 16, 2020 at 7:41 PM Roman Gushchin <[email protected]> wrote:
> > > > > >> >
> > > > > >> > On Tue, Jun 16, 2020 at 06:46:56PM -0700, Shakeel Butt wrote:
> > > > > >> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
> > > > > >> > > >
> > > > > >> [...]
> > > > > >> > >
> > > > > >> > > Have you performed any [perf] testing on SLAB with this patchset?
> > > > > >> >
> > > > > >> > The accounting part is the same for SLAB and SLUB, so there should be no
> > > > > >> > significant difference. I've checked that it compiles, boots and passes
> > > > > >> > kselftests. And that memory savings are there.
> > > > > >> >
> > > > > >>
> > > > > >> What about performance? Also you mentioned that sharing kmem-cache
> > > > > >> between accounted and non-accounted can have additional overhead. Any
> > > > > >> difference between SLAB and SLUB for such a case?
> > > > > >
> > > > > > Not really.
> > > > > >
> > > > > > Sharing a single set of caches adds some overhead to root- and non-accounted
> > > > > > allocations, which is something I've tried hard to avoid in my original version.
> > > > > > But I have to admit, it allows to simplify and remove a lot of code, and here
> > > > > > it's hard to argue with Johanness, who pushed on this design.
> > > > > >
> > > > > > With performance testing it's not that easy, because it's not obvious what
> > > > > > we wanna test. Obviously, per-object accounting is more expensive, and
> > > > > > measuring something like 1000000 allocations and deallocations in a line from
> > > > > > a single kmem_cache will show a regression. But in the real world the relative
> > > > > > cost of allocations is usually low, and we can get some benefits from a smaller
> > > > > > working set and from having shared kmem_cache objects cache hot.
> > > > > > Not speaking about some extra memory and the fragmentation reduction.
> > > > > >
> > > > > > We've done an extensive testing of the original version in Facebook production,
> > > > > > and we haven't noticed any regressions so far. But I have to admit, we were
> > > > > > using an original version with two sets of kmem_caches.
> > > > > >
> > > > > > If you have any specific tests in mind, I can definitely run them. Or if you
> > > > > > can help with the performance evaluation, I'll appreciate it a lot.
> > > > >
> > > > > Jesper provided some pointers here [1], it would be really great if you could
> > > > > run at least those microbenchmarks. With mmtests it's the major question of
> > > > > which subset/profiles to run, maybe the referenced commits provide some hints,
> > > > > or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
> > > > >
> > > > > [1] https://lore.kernel.org/linux-mm/20200527103545.4348ac10@carbon/
> > > >
> > > > Oh, Jesper, I'm really sorry, somehow I missed your mail.
> > > > Thank you, Vlastimil, for pointing at it.
> > > >
> > > > I've got some results (slab_bulk_test01), but honestly I fail to interpret them.
> > > >
> > > > I ran original vs patched with SLUB and SLAB, each test several times and picked
> > > > 3 which looked most consistently. But it still looks very noisy.
> > > >
> > > > I ran them on my desktop (8-core Ryzen 1700, 16 GB RAM, Fedora 32),
> > > > it's 5.8-rc1 + slab controller v6 vs 5.8-rc1 (default config from Fedora 32).
> > >
> > > What about running these tests on the server level hardware, that you
> > > intent to run this on?
> >
> > To give you an idea of the performance difference I ran the same test
> > on a Broadwell Intel(R) Xeon(R) CPU E5-1650 v4 @ 3.60GHz.
> >
> > The SLUB fastpath:
> > Type:kmem fastpath reuse Per elem: 60 cycles(tsc) 16.822 ns
> >
> >
> > > >
> > > > How should I interpret this data?
> > >
> > > First of all these SLUB+SLAB microbenchmarks use object size 256 bytes,
> > > because network stack alloc object of this size for SKBs/sk_buff (due
> > > to cache-align as used size is 224 bytes). Checked SLUB: Each slab use
> > > 2 pages (8192 bytes) and contain 32 object of size 256 (256*32=8192).
> > >
> > > The SLUB allocator have a per-CPU slab which speedup fast-reuse, in this
> > > case up-to 32 objects. For SLUB the "fastpath reuse" test this behaviour,
> > > and it serves as a baseline for optimal 1-object performance (where my bulk
> > > API tries to beat that, which is possible even for 1-object due to knowing
> > > bulk API cannot be used from IRQ context).
> > >
> > > SLUB fastpath: 3 measurements reporting cycles(tsc)
> > > - SLUB-patched : fastpath reuse: 184 - 177 - 176 cycles(tsc)
> > > - SLUB-original: fastpath reuse: 178 - 153 - 156 cycles(tsc)
> > >
> >
> > For your SLAB results:
> >
> > SLAB fastpath: 3 measurements reporting cycles(tsc)
> > - SLAB-patched : 161 - 160 - 163 cycles(tsc)
> > - SLAB-original: 174 - 170 - 159 cycles(tsc)
> >
> > I find it strange that SLAB is slightly better than SLUB (in many
> > measurements), because SLUB should have an advantage on this fast-path
> > quick reuse due to the per-CPU slabs. Maybe this is also related to
> > the CPU arch you are using?
> >
> >
> > > There are some stability concerns as you mention, but it seems pretty
> > > consistently that patched version is slower. If you compile with
> > > no-PREEMPT you can likely get more stable results (and remove a slight
> > > overhead for SLUB fastpath).
> > >
> > > The microbenchmark also measures the bulk-API, which is AFAIK only used
> > > by network stack (and io_uring). I guess you shouldn't focus too much
> > > on these bulk measurements. When bulk-API cross this objects per slab
> > > threshold, or is unlucky is it use two per-CPU slab, then the
> > > measurements can fluctuate a bit.
> > >
> > > Your numbers for SLUB bulk-API:
> > >
> > > SLUB-patched - bulk-API
> > > - SLUB-patched : bulk_quick_reuse objects=1 : 187 - 90 - 224 cycles(tsc)
> > > - SLUB-patched : bulk_quick_reuse objects=2 : 110 - 53 - 133 cycles(tsc)
> > > - SLUB-patched : bulk_quick_reuse objects=3 : 88 - 95 - 42 cycles(tsc)
> > > - SLUB-patched : bulk_quick_reuse objects=4 : 91 - 85 - 36 cycles(tsc)
> > > - SLUB-patched : bulk_quick_reuse objects=8 : 32 - 66 - 32 cycles(tsc)
> > >
> > > SLUB-original - bulk-API
> > > - SLUB-original: bulk_quick_reuse objects=1 : 87 - 87 - 142 cycles(tsc)
> > > - SLUB-original: bulk_quick_reuse objects=2 : 52 - 53 - 53 cycles(tsc)
> > > - SLUB-original: bulk_quick_reuse objects=3 : 42 - 42 - 91 cycles(tsc)
> > > - SLUB-original: bulk_quick_reuse objects=4 : 91 - 37 - 37 cycles(tsc)
> > > - SLUB-original: bulk_quick_reuse objects=8 : 31 - 79 - 76 cycles(tsc)
> >
> > Your numbers for SLAB bulk-API:
> >
> > SLAB-patched - bulk-API
> > - SLAB-patched : bulk_quick_reuse objects=1 : 67 - 67 - 140 cycles(tsc)
> > - SLAB-patched : bulk_quick_reuse objects=2 : 55 - 46 - 46 cycles(tsc)
> > - SLAB-patched : bulk_quick_reuse objects=3 : 93 - 94 - 39 cycles(tsc)
> > - SLAB-patched : bulk_quick_reuse objects=4 : 35 - 88 - 85 cycles(tsc)
> > - SLAB-patched : bulk_quick_reuse objects=8 : 30 - 30 - 30 cycles(tsc)
> >
> > SLAB-original- bulk-API
> > - SLAB-original: bulk_quick_reuse objects=1 : 143 - 136 - 67 cycles(tsc)
> > - SLAB-original: bulk_quick_reuse objects=2 : 45 - 46 - 46 cycles(tsc)
> > - SLAB-original: bulk_quick_reuse objects=3 : 38 - 39 - 39 cycles(tsc)
> > - SLAB-original: bulk_quick_reuse objects=4 : 35 - 87 - 87 cycles(tsc)
> > - SLAB-original: bulk_quick_reuse objects=8 : 29 - 66 - 30 cycles(tsc)
> >
> > In case of SLAB I expect the bulk-API to be slightly faster than SLUB,
> > as the SLUB bulk code is much more advanced.
>
> So again it looks like a patched version is only slightly worse if we're taking
> the smallest number in each series. Is it a correct assumption?
Yes, I guess that is a good way to look at these somewhat fluctuating numbers.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
On Fri, Jun 19, 2020 at 11:39:45AM +0200, Jesper Dangaard Brouer wrote:
> On Thu, 18 Jun 2020 18:27:12 -0700
> Roman Gushchin <[email protected]> wrote:
>
> > Theoretically speaking it should get worse (especially for non-root allocations),
> > but if the difference is not big, it still should be better, because there is
> > a big expected win from memory savings/smaller working set/less fragmentation etc.
> >
> > The only thing I'm slightly worried is what's the effect on root allocations
> > if we're sharing slab caches between root- and non-root allocations. Because if
> > someone depends so much on the allocation speed, memcg-based accounting can be
> > ignored anyway. For most users the cost of allocation is negligible.
> > That's why the patch which merges root- and memcg slab caches is put on top
> > and can be reverted if somebody will complain.
>
> In general I like this work for saving memory, but you also have to be
> aware of the negative consequences of sharing slab caches. At Red Hat
> we have experienced very hard to find kernel bugs, that point to memory
> corruption at a completely wrong kernel code, because other kernel code
> were corrupting the shared slab cache. (Hint a workaround is to enable
> SLUB debugging to disable this sharing).
I agree, but it must be related to the sharing of slab pages between different
types of objects. We've also disabled cache sharing many times in order
to compare slab usages between different major kernel version or to debug
memory corruptions.
But what about sharing between multiple cgroups, it just brings
CONFIG_MEMCG_KMEM memory layout back to the !CONFIG_MEMCG_KMEM.
I doubt that anyone ever considered the kernel memory accounting
as a debugging mechanism. Quite opposite, we've encountered a lot of
tricky issues related to the dynamic creation and destruction of kmem_caches
and their life-time. Removing this code should make things simpler and
hopefully more reliable.
Thanks!
On Wed, Jun 17, 2020 at 03:31:10PM +0100, Mel Gorman wrote:
> On Wed, Jun 17, 2020 at 01:24:21PM +0200, Vlastimil Babka wrote:
> > > Not really.
> > >
> > > Sharing a single set of caches adds some overhead to root- and non-accounted
> > > allocations, which is something I've tried hard to avoid in my original version.
> > > But I have to admit, it allows to simplify and remove a lot of code, and here
> > > it's hard to argue with Johanness, who pushed on this design.
> > >
> > > With performance testing it's not that easy, because it's not obvious what
> > > we wanna test. Obviously, per-object accounting is more expensive, and
> > > measuring something like 1000000 allocations and deallocations in a line from
> > > a single kmem_cache will show a regression. But in the real world the relative
> > > cost of allocations is usually low, and we can get some benefits from a smaller
> > > working set and from having shared kmem_cache objects cache hot.
> > > Not speaking about some extra memory and the fragmentation reduction.
> > >
> > > We've done an extensive testing of the original version in Facebook production,
> > > and we haven't noticed any regressions so far. But I have to admit, we were
> > > using an original version with two sets of kmem_caches.
> > >
> > > If you have any specific tests in mind, I can definitely run them. Or if you
> > > can help with the performance evaluation, I'll appreciate it a lot.
> >
> > Jesper provided some pointers here [1], it would be really great if you could
> > run at least those microbenchmarks. With mmtests it's the major question of
> > which subset/profiles to run, maybe the referenced commits provide some hints,
> > or maybe Mel could suggest what he used to evaluate SLAB vs SLUB not so long ago.
> >
>
> Last time the list of mmtests configurations I used for a basic
> comparison were
>
> db-pgbench-timed-ro-small-ext4
> db-pgbench-timed-ro-small-xfs
> io-dbench4-async-ext4
> io-dbench4-async-xfs
> io-bonnie-dir-async-ext4
> io-bonnie-dir-async-xfs
> io-bonnie-file-async-ext4
> io-bonnie-file-async-xfs
> io-fsmark-xfsrepair-xfs
> io-metadata-xfs
> network-netperf-unbound
> network-netperf-cross-node
> network-netperf-cross-socket
> network-sockperf-unbound
> network-netperf-unix-unbound
> network-netpipe
> network-tbench
> pagereclaim-shrinker-ext4
> scheduler-unbound
> scheduler-forkintensive
> workload-kerndevel-xfs
> workload-thpscale-madvhugepage-xfs
> workload-thpscale-xfs
>
> Some were more valid than others in terms of doing an evaluation. I
> followed up later with a more comprehensive comparison but that was
> overkill.
>
> Each time I did a slab/slub comparison in the past, I had to reverify
> the rate that kmem_cache_* functions were actually being called as the
> pattern can change over time even for the same workload. A comparison
> gets more complicated when comparing cgroups as ideally there would be
> workloads running in multiple group but that gets complex and I think
> it's reasonable to just test the "basic" case without cgroups.
Thank you Mel for the suggestion!
I'll try to come up with some numbers soon. I guess networking tests
will be most interesting in this case.
Thanks!
Roman
On Mon, Jun 08, 2020 at 04:06:35PM -0700, Roman Gushchin wrote:
> This is v6 of the slab cgroup controller rework.
>
> The patchset moves the accounting from the page level to the object
> level. It allows to share slab pages between memory cgroups.
> This leads to a significant win in the slab utilization (up to 45%)
> and the corresponding drop in the total kernel memory footprint.
> The reduced number of unmovable slab pages should also have a positive
> effect on the memory fragmentation.
>
> The patchset makes the slab accounting code simpler: there is no more
> need in the complicated dynamic creation and destruction of per-cgroup
> slab caches, all memory cgroups use a global set of shared slab caches.
> The lifetime of slab caches is not more connected to the lifetime
> of memory cgroups.
>
> The more precise accounting does require more CPU, however in practice
> the difference seems to be negligible. We've been using the new slab
> controller in Facebook production for several months with different
> workloads and haven't seen any noticeable regressions. What we've seen
> were memory savings in order of 1 GB per host (it varied heavily depending
> on the actual workload, size of RAM, number of CPUs, memory pressure, etc).
>
> The third version of the patchset added yet another step towards
> the simplification of the code: sharing of slab caches between
> accounted and non-accounted allocations. It comes with significant
> upsides (most noticeable, a complete elimination of dynamic slab caches
> creation) but not without some regression risks, so this change sits
> on top of the patchset and is not completely merged in. So in the unlikely
> event of a noticeable performance regression it can be reverted separately.
Reverting this series and its dependency [1], i.e.,
git revert --no-edit 05923a2ccacd..07666ee77fb4
on the top of next-20200621 fixed an issue where kmemleak could report
thousands of leaks like this below using this .config (if ever matters),
https://github.com/cailca/linux-mm/blob/master/x86.config
unreferenced object 0xffff888ff2bf6200 (size 512):
comm "systemd-udevd", pid 794, jiffies 4294940381 (age 602.740s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e8e9272e>] __kmalloc_node+0x149/0x260
[<0000000021c1b4a2>] slab_post_alloc_hook+0x172/0x4d0
[<00000000f38fad30>] kmem_cache_alloc_node+0x110/0x2e0
[<00000000fdf1d747>] __alloc_skb+0x92/0x520
[<00000000bda2c48f>] alloc_skb_with_frags+0x72/0x530
[<0000000023d10084>] sock_alloc_send_pskb+0x5a1/0x720
[<00000000dd3334cc>] unix_dgram_sendmsg+0x32a/0xe70
[<000000001ad988ff>] sock_write_iter+0x341/0x420
[<0000000056d15d07>] new_sync_write+0x4b6/0x610
[<0000000090b14475>] vfs_write+0x18b/0x4d0
[<000000009e7ba1b4>] ksys_write+0x180/0x1c0
[<00000000713e3b98>] do_syscall_64+0x5f/0x310
[<00000000b1c204e0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
unreferenced object 0xffff8888040fac00 (size 512):
comm "systemd-udevd", pid 1096, jiffies 4294941658 (age 590.010s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e8e9272e>] __kmalloc_node+0x149/0x260
[<0000000021c1b4a2>] slab_post_alloc_hook+0x172/0x4d0
[<00000000e26f0785>] kmem_cache_alloc+0xe5/0x2a0
[<00000000ac28147d>] __alloc_file+0x22/0x2a0
[<0000000031c82651>] alloc_empty_file+0x3e/0x100
[<000000000e337bda>] path_openat+0x10c/0x1b00
[<000000008969cf2d>] do_filp_open+0x171/0x240
[<000000009462ef7b>] do_sys_openat2+0x2db/0x500
[<0000000007340ff0>] do_sys_open+0x85/0xd0
[<00000000713e3b98>] do_syscall_64+0x5f/0x310
[<00000000b1c204e0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
unreferenced object 0xffff8885bf0c8200 (size 512):
comm "systemd-udevd", pid 1075, jiffies 4294941661 (age 589.980s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e8e9272e>] __kmalloc_node+0x149/0x260
[<0000000021c1b4a2>] slab_post_alloc_hook+0x172/0x4d0
[<00000000e26f0785>] kmem_cache_alloc+0xe5/0x2a0
[<00000000ac28147d>] __alloc_file+0x22/0x2a0
[<0000000031c82651>] alloc_empty_file+0x3e/0x100
[<000000000e337bda>] path_openat+0x10c/0x1b00
[<000000008969cf2d>] do_filp_open+0x171/0x240
[<000000009462ef7b>] do_sys_openat2+0x2db/0x500
[<0000000007340ff0>] do_sys_open+0x85/0xd0
[<00000000713e3b98>] do_syscall_64+0x5f/0x310
[<00000000b1c204e0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
unreferenced object 0xffff88903ce24a00 (size 512):
comm "systemd-udevd", pid 1078, jiffies 4294941806 (age 588.540s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e8e9272e>] __kmalloc_node+0x149/0x260
[<0000000021c1b4a2>] slab_post_alloc_hook+0x172/0x4d0
[<00000000e26f0785>] kmem_cache_alloc+0xe5/0x2a0
[<0000000002285574>] vm_area_dup+0x71/0x2a0
[<000000006c732816>] dup_mm+0x548/0xfc0
[<000000001cf5c685>] copy_process+0x2a33/0x62c0
[<000000006e2a8069>] _do_fork+0xf8/0xce0
[<00000000e7ba268e>] __do_sys_clone+0xda/0x120
[<00000000713e3b98>] do_syscall_64+0x5f/0x310
[<00000000b1c204e0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[1] https://lore.kernel.org/linux-mm/[email protected]/
Also, confirmed that only reverting the "mm: memcg accounting of percpu
memory" series alone did not help.
>
> v6:
> 1) rebased on top of the mm tree
> 2) removed a redundant check from cache_from_obj(), suggested by Vlastimil
>
> v5:
> 1) fixed a build error, spotted by Vlastimil
> 2) added a comment about memcg->nr_charged_bytes, asked by Johannes
> 3) added missed acks and reviews
>
> v4:
> 1) rebased on top of the mm tree, some fixes here and there
> 2) merged obj_to_index() with slab_index(), suggested by Vlastimil
> 3) changed objects_per_slab() to a better objects_per_slab_page(),
> suggested by Vlastimil
> 4) other minor fixes and changes
>
> v3:
> 1) added a patch that switches to a global single set of kmem_caches
> 2) kmem API clean up dropped, because if has been already merged
> 3) byte-sized slab vmstat API over page-sized global counters and
> bytes-sized memcg/lruvec counters
> 3) obj_cgroup refcounting simplifications and other minor fixes
> 4) other minor changes
>
> v2:
> 1) implemented re-layering and renaming suggested by Johannes,
> added his patch to the set. Thanks!
> 2) fixed the issue discovered by Bharata B Rao. Thanks!
> 3) added kmem API clean up part
> 4) added slab/memcg follow-up clean up part
> 5) fixed a couple of issues discovered by internal testing on FB fleet.
> 6) added kselftests
> 7) included metadata into the charge calculation
> 8) refreshed commit logs, regrouped patches, rebased onto mm tree, etc
>
> v1:
> 1) fixed a bug in zoneinfo_show_print()
> 2) added some comments to the subpage charging API, a minor fix
> 3) separated memory.kmem.slabinfo deprecation into a separate patch,
> provided a drgn-based replacement
> 4) rebased on top of the current mm tree
>
> RFC:
> https://lwn.net/Articles/798605/
>
>
> Johannes Weiner (1):
> mm: memcontrol: decouple reference counting from page accounting
>
> Roman Gushchin (18):
> mm: memcg: factor out memcg- and lruvec-level changes out of
> __mod_lruvec_state()
> mm: memcg: prepare for byte-sized vmstat items
> mm: memcg: convert vmstat slab counters to bytes
> mm: slub: implement SLUB version of obj_to_index()
> mm: memcg/slab: obj_cgroup API
> mm: memcg/slab: allocate obj_cgroups for non-root slab pages
> mm: memcg/slab: save obj_cgroup for non-root slab objects
> mm: memcg/slab: charge individual slab objects instead of pages
> mm: memcg/slab: deprecate memory.kmem.slabinfo
> mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h
> mm: memcg/slab: use a single set of kmem_caches for all accounted
> allocations
> mm: memcg/slab: simplify memcg cache creation
> mm: memcg/slab: remove memcg_kmem_get_cache()
> mm: memcg/slab: deprecate slab_root_caches
> mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo()
> mm: memcg/slab: use a single set of kmem_caches for all allocations
> kselftests: cgroup: add kernel memory accounting tests
> tools/cgroup: add memcg_slabinfo.py tool
>
> drivers/base/node.c | 6 +-
> fs/proc/meminfo.c | 4 +-
> include/linux/memcontrol.h | 85 ++-
> include/linux/mm_types.h | 5 +-
> include/linux/mmzone.h | 24 +-
> include/linux/slab.h | 5 -
> include/linux/slab_def.h | 9 +-
> include/linux/slub_def.h | 31 +-
> include/linux/vmstat.h | 14 +-
> kernel/power/snapshot.c | 2 +-
> mm/memcontrol.c | 608 +++++++++++--------
> mm/oom_kill.c | 2 +-
> mm/page_alloc.c | 8 +-
> mm/slab.c | 70 +--
> mm/slab.h | 372 +++++-------
> mm/slab_common.c | 643 +--------------------
> mm/slob.c | 12 +-
> mm/slub.c | 229 +-------
> mm/vmscan.c | 3 +-
> mm/vmstat.c | 30 +-
> mm/workingset.c | 6 +-
> tools/cgroup/memcg_slabinfo.py | 226 ++++++++
> tools/testing/selftests/cgroup/.gitignore | 1 +
> tools/testing/selftests/cgroup/Makefile | 2 +
> tools/testing/selftests/cgroup/test_kmem.c | 382 ++++++++++++
> 25 files changed, 1374 insertions(+), 1405 deletions(-)
> create mode 100755 tools/cgroup/memcg_slabinfo.py
> create mode 100644 tools/testing/selftests/cgroup/test_kmem.c
>
> --
> 2.25.4
>
>
On Sun, Jun 21, 2020 at 06:57:52PM -0400, Qian Cai wrote:
> On Mon, Jun 08, 2020 at 04:06:35PM -0700, Roman Gushchin wrote:
> > This is v6 of the slab cgroup controller rework.
> >
> > The patchset moves the accounting from the page level to the object
> > level. It allows to share slab pages between memory cgroups.
> > This leads to a significant win in the slab utilization (up to 45%)
> > and the corresponding drop in the total kernel memory footprint.
> > The reduced number of unmovable slab pages should also have a positive
> > effect on the memory fragmentation.
> >
> > The patchset makes the slab accounting code simpler: there is no more
> > need in the complicated dynamic creation and destruction of per-cgroup
> > slab caches, all memory cgroups use a global set of shared slab caches.
> > The lifetime of slab caches is not more connected to the lifetime
> > of memory cgroups.
> >
> > The more precise accounting does require more CPU, however in practice
> > the difference seems to be negligible. We've been using the new slab
> > controller in Facebook production for several months with different
> > workloads and haven't seen any noticeable regressions. What we've seen
> > were memory savings in order of 1 GB per host (it varied heavily depending
> > on the actual workload, size of RAM, number of CPUs, memory pressure, etc).
> >
> > The third version of the patchset added yet another step towards
> > the simplification of the code: sharing of slab caches between
> > accounted and non-accounted allocations. It comes with significant
> > upsides (most noticeable, a complete elimination of dynamic slab caches
> > creation) but not without some regression risks, so this change sits
> > on top of the patchset and is not completely merged in. So in the unlikely
> > event of a noticeable performance regression it can be reverted separately.
>
> Reverting this series and its dependency [1], i.e.,
>
> git revert --no-edit 05923a2ccacd..07666ee77fb4
>
> on the top of next-20200621 fixed an issue where kmemleak could report
> thousands of leaks like this below using this .config (if ever matters),
>
> https://github.com/cailca/linux-mm/blob/master/x86.config
>
> unreferenced object 0xffff888ff2bf6200 (size 512):
Hi Qian!
My wild guess is that kmemleak is getting confused by modifying the lowest
bit of page->mem_cgroup/obhj_cgroups pointer:
struct page {
...
union {
struct mem_cgroup *mem_cgroup;
struct obj_cgroup **obj_cgroups;
};
...
}
We're using the lowest bit to distinguish between a "normal" mem_cgroup
pointer and a vector of obj_cgroup pointers.
This pointer to obj_cgroup vector is saved only here, so if we're modifying
the address, I guess it's what makes kmemleak think that there is a leak.
Or do you have a real leak?
Thanks!
> On Jun 21, 2020, at 7:34 PM, Roman Gushchin <[email protected]> wrote:
>
> My wild guess is that kmemleak is getting confused by modifying the lowest
> bit of page->mem_cgroup/obhj_cgroups pointer:
>
> struct page {
> ...
> union {
> struct mem_cgroup *mem_cgroup;
> struct obj_cgroup **obj_cgroups;
> };
> ...
> }
>
> We're using the lowest bit to distinguish between a "normal" mem_cgroup
> pointer and a vector of obj_cgroup pointers.
>
> This pointer to obj_cgroup vector is saved only here, so if we're modifying
> the address, I guess it's what makes kmemleak think that there is a leak.
>
> Or do you have a real leak?
The point is that we can’t have a patchset in the current form to totally render kmemleak useless with so many even false positives.
Anyway, this is rather easy to reproduce where I am able to reproduce on multiple bare-metal machines by just booting it.
# echo scan > /sys/kernel/debug/kmemleak
# cat /sys/kernel/debug/kmemleak
On Sun, Jun 21, 2020 at 07:53:23PM -0400, Qian Cai wrote:
>
>
> > On Jun 21, 2020, at 7:34 PM, Roman Gushchin <[email protected]> wrote:
> >
> > My wild guess is that kmemleak is getting confused by modifying the lowest
> > bit of page->mem_cgroup/obhj_cgroups pointer:
> >
> > struct page {
> > ...
> > union {
> > struct mem_cgroup *mem_cgroup;
> > struct obj_cgroup **obj_cgroups;
> > };
> > ...
> > }
> >
> > We're using the lowest bit to distinguish between a "normal" mem_cgroup
> > pointer and a vector of obj_cgroup pointers.
> >
> > This pointer to obj_cgroup vector is saved only here, so if we're modifying
> > the address, I guess it's what makes kmemleak think that there is a leak.
> >
> > Or do you have a real leak?
>
> The point is that we can’t have a patchset in the current form to totally render kmemleak useless with so many even false positives.
>
> Anyway, this is rather easy to reproduce where I am able to reproduce on multiple bare-metal machines by just booting it.
>
> # echo scan > /sys/kernel/debug/kmemleak
> # cat /sys/kernel/debug/kmemleak
Ok, thank you for the report, I'll take care of it.
It's easy to mark these vectors to be ignored by kmemleak, but I guess it's better
to explicitly add an additional reference, so we can track actual leaks.
I'll send a patch with fix soon-ish.
Thanks!
On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
>
> This is fairly big but mostly red patch, which makes all accounted
> slab allocations use a single set of kmem_caches instead of
> creating a separate set for each memory cgroup.
>
> Because the number of non-root kmem_caches is now capped by the number
> of root kmem_caches, there is no need to shrink or destroy them
> prematurely. They can be perfectly destroyed together with their
> root counterparts. This allows to dramatically simplify the
> management of non-root kmem_caches and delete a ton of code.
>
> This patch performs the following changes:
> 1) introduces memcg_params.memcg_cache pointer to represent the
> kmem_cache which will be used for all non-root allocations
> 2) reuses the existing memcg kmem_cache creation mechanism
> to create memcg kmem_cache on the first allocation attempt
> 3) memcg kmem_caches are named <kmemcache_name>-memcg,
> e.g. dentry-memcg
> 4) simplifies memcg_kmem_get_cache() to just return memcg kmem_cache
> or schedule it's creation and return the root cache
> 5) removes almost all non-root kmem_cache management code
> (separate refcounter, reparenting, shrinking, etc)
> 6) makes slab debugfs to display root_mem_cgroup css id and never
> show :dead and :deact flags in the memcg_slabinfo attribute.
>
> Following patches in the series will simplify the kmem_cache creation.
>
> Signed-off-by: Roman Gushchin <[email protected]>
> Reviewed-by: Vlastimil Babka <[email protected]>
This is a very satisfying patch.
Reviewed-by: Shakeel Butt <[email protected]>
On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote:
>
> The memcg_kmem_get_cache() function became really trivial,
> so let's just inline it into the single call point:
> memcg_slab_pre_alloc_hook().
>
> It will make the code less bulky and can also help the compiler
> to generate a better code.
>
> Signed-off-by: Roman Gushchin <[email protected]>
> Reviewed-by: Vlastimil Babka <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>