alloc_calls and free_calls implementation in sysfs have two issues,
one is PAGE_SIZE limitiation of sysfs and other is it does not adhere
to "one value per file" rule.
To overcome this issues, move the alloc_calls and free_calls implemeation
to debugfs.
Debugfs cache will be created if SLAB_STORE_USER flag is set.
Rename the alloc_calls/free_calls to alloc_traces/free_traces,
to be inline with what it does.
Signed-off-by: Faiyaz Mohammed <[email protected]>
---
changes in v8:
- Debugfs cache file will not be created if SLAB_STORE_USER flag is not set.
- Make sure the debugfs slab release happen before slab kmem cahce release.
changes in V7:
- https://lore.kernel.org/linux-mm/[email protected]/
changes in v6:
- https://lore.kernel.org/linux-mm/[email protected]/
changes in v5:
- https://lore.kernel.org/linux-mm/[email protected]/
changes in v4:
- https://lore.kernel.org/linux-mm/[email protected]/
changes in v3:
- https://lore.kernel.org/linux-mm/[email protected]/
changes in v2:
- https://lore.kernel.org/linux-mm/[email protected]/
changes in v1
- https://lore.kernel.org/linux-mm/[email protected]/
include/linux/slab_def.h | 2 +
include/linux/slub_def.h | 8 ++
mm/slab_common.c | 3 +
mm/slub.c | 306 +++++++++++++++++++++++++++++++++--------------
4 files changed, 226 insertions(+), 93 deletions(-)
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 3aa5e1e..02ca311 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -120,4 +120,6 @@ static inline int objs_per_slab_page(const struct kmem_cache *cache,
return cache->num;
}
+static inline void debugfs_slab_release(struct kmem_cache *s) { }
+
#endif /* _LINUX_SLAB_DEF_H */
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index dcde82a..90d659a 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -159,6 +159,14 @@ static inline void sysfs_slab_release(struct kmem_cache *s)
}
#endif
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
+void debugfs_slab_release(struct kmem_cache *);
+#else
+static inline void debugfs_slab_release(struct kmem_cache *s)
+{
+}
+#endif
+
void object_err(struct kmem_cache *s, struct page *page,
u8 *object, char *reason);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a4a5714..ca39e84 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -449,6 +449,7 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
rcu_barrier();
list_for_each_entry_safe(s, s2, &to_destroy, list) {
+ debugfs_slab_release(s);
kfence_shutdown_cache(s);
#ifdef SLAB_SUPPORTS_SYSFS
sysfs_slab_release(s);
@@ -469,6 +470,7 @@ static int shutdown_cache(struct kmem_cache *s)
list_del(&s->list);
if (s->flags & SLAB_TYPESAFE_BY_RCU) {
+ debugfs_slab_release(s);
#ifdef SLAB_SUPPORTS_SYSFS
sysfs_slab_unlink(s);
#endif
@@ -476,6 +478,7 @@ static int shutdown_cache(struct kmem_cache *s)
schedule_work(&slab_caches_to_rcu_destroy_work);
} else {
kfence_shutdown_cache(s);
+ debugfs_slab_release(s);
#ifdef SLAB_SUPPORTS_SYSFS
sysfs_slab_unlink(s);
sysfs_slab_release(s);
diff --git a/mm/slub.c b/mm/slub.c
index 3f96e09..f7735c1 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -36,6 +36,7 @@
#include <linux/memcontrol.h>
#include <linux/random.h>
+#include <linux/debugfs.h>
#include <trace/events/kmem.h>
#include "internal.h"
@@ -225,6 +226,12 @@ static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
{ return 0; }
#endif
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
+static void debugfs_slab_add(struct kmem_cache *);
+#else
+static inline void debugfs_slab_add(struct kmem_cache *s) { }
+#endif
+
static inline void stat(const struct kmem_cache *s, enum stat_item si)
{
#ifdef CONFIG_SLUB_STATS
@@ -4546,6 +4553,9 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags)
if (err)
__kmem_cache_release(s);
+ if (s->flags & SLAB_STORE_USER)
+ debugfs_slab_add(s);
+
return err;
}
@@ -4686,6 +4696,8 @@ static long validate_slab_cache(struct kmem_cache *s)
return count;
}
+
+#ifdef CONFIG_DEBUG_FS
/*
* Generate lists of code addresses where slabcache objects are allocated
* and freed.
@@ -4709,6 +4721,9 @@ struct loc_track {
struct location *loc;
};
+static struct dentry *slab_debugfs_root;
+struct loc_track t = { 0, 0, NULL };
+
static void free_loc_track(struct loc_track *t)
{
if (t->max)
@@ -4825,82 +4840,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
add_location(t, s, get_track(s, p, alloc));
put_map(map);
}
-
-static int list_locations(struct kmem_cache *s, char *buf,
- enum track_item alloc)
-{
- int len = 0;
- unsigned long i;
- struct loc_track t = { 0, 0, NULL };
- int node;
- struct kmem_cache_node *n;
-
- if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
- GFP_KERNEL)) {
- return sysfs_emit(buf, "Out of memory\n");
- }
- /* Push back cpu slabs */
- flush_all(s);
-
- for_each_kmem_cache_node(s, node, n) {
- unsigned long flags;
- struct page *page;
-
- if (!atomic_long_read(&n->nr_slabs))
- continue;
-
- spin_lock_irqsave(&n->list_lock, flags);
- list_for_each_entry(page, &n->partial, slab_list)
- process_slab(&t, s, page, alloc);
- list_for_each_entry(page, &n->full, slab_list)
- process_slab(&t, s, page, alloc);
- spin_unlock_irqrestore(&n->list_lock, flags);
- }
-
- for (i = 0; i < t.count; i++) {
- struct location *l = &t.loc[i];
-
- len += sysfs_emit_at(buf, len, "%7ld ", l->count);
-
- if (l->addr)
- len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr);
- else
- len += sysfs_emit_at(buf, len, "<not-available>");
-
- if (l->sum_time != l->min_time)
- len += sysfs_emit_at(buf, len, " age=%ld/%ld/%ld",
- l->min_time,
- (long)div_u64(l->sum_time,
- l->count),
- l->max_time);
- else
- len += sysfs_emit_at(buf, len, " age=%ld", l->min_time);
-
- if (l->min_pid != l->max_pid)
- len += sysfs_emit_at(buf, len, " pid=%ld-%ld",
- l->min_pid, l->max_pid);
- else
- len += sysfs_emit_at(buf, len, " pid=%ld",
- l->min_pid);
-
- if (num_online_cpus() > 1 &&
- !cpumask_empty(to_cpumask(l->cpus)))
- len += sysfs_emit_at(buf, len, " cpus=%*pbl",
- cpumask_pr_args(to_cpumask(l->cpus)));
-
- if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
- len += sysfs_emit_at(buf, len, " nodes=%*pbl",
- nodemask_pr_args(&l->nodes));
-
- len += sysfs_emit_at(buf, len, "\n");
- }
-
- free_loc_track(&t);
- if (!t.count)
- len += sysfs_emit_at(buf, len, "No data\n");
-
- return len;
-}
+#endif /* CONFIG_DEBUG_FS */
#endif /* CONFIG_SLUB_DEBUG */
#ifdef SLUB_RESILIENCY_TEST
@@ -5350,21 +5290,6 @@ static ssize_t validate_store(struct kmem_cache *s,
}
SLAB_ATTR(validate);
-static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
-{
- if (!(s->flags & SLAB_STORE_USER))
- return -ENOSYS;
- return list_locations(s, buf, TRACK_ALLOC);
-}
-SLAB_ATTR_RO(alloc_calls);
-
-static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
-{
- if (!(s->flags & SLAB_STORE_USER))
- return -ENOSYS;
- return list_locations(s, buf, TRACK_FREE);
-}
-SLAB_ATTR_RO(free_calls);
#endif /* CONFIG_SLUB_DEBUG */
#ifdef CONFIG_FAILSLAB
@@ -5528,8 +5453,6 @@ static struct attribute *slab_attrs[] = {
&poison_attr.attr,
&store_user_attr.attr,
&validate_attr.attr,
- &alloc_calls_attr.attr,
- &free_calls_attr.attr,
#endif
#ifdef CONFIG_ZONE_DMA
&cache_dma_attr.attr,
@@ -5818,6 +5741,203 @@ static int __init slab_sysfs_init(void)
__initcall(slab_sysfs_init);
#endif /* CONFIG_SYSFS */
+#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
+static int slab_debugfs_show(struct seq_file *seq, void *v)
+{
+
+ struct location *l;
+ unsigned int idx = *(unsigned int *)v;
+
+ if (idx < t.count) {
+ l = &t.loc[idx];
+
+ seq_printf(seq, "%7ld ", l->count);
+
+ if (l->addr)
+ seq_printf(seq, "%pS", (void *)l->addr);
+ else
+ seq_puts(seq, "<not-available>");
+
+ if (l->sum_time != l->min_time) {
+ seq_printf(seq, " age=%ld/%ld/%ld",
+ l->min_time,
+ (long)div_u64(l->sum_time, l->count),
+ l->max_time);
+ } else
+ seq_printf(seq, " age=%ld",
+ l->min_time);
+
+ if (l->min_pid != l->max_pid)
+ seq_printf(seq, " pid=%ld-%ld",
+ l->min_pid, l->max_pid);
+ else
+ seq_printf(seq, " pid=%ld",
+ l->min_pid);
+
+ if (num_online_cpus() > 1 &&
+ !cpumask_empty(to_cpumask(l->cpus)))
+ seq_printf(seq, " cpus=%*pbl",
+ cpumask_pr_args(to_cpumask(l->cpus)));
+
+ if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
+ seq_printf(seq, " nodes=%*pbl",
+ nodemask_pr_args(&l->nodes));
+
+ seq_puts(seq, "\n");
+ }
+
+ if (t.count == 0)
+ seq_puts(seq, "No data\n");
+
+ return 0;
+}
+
+static void slab_debugfs_stop(struct seq_file *seq, void *v)
+{
+ if (!v && t.max) {
+ free_loc_track(&t);
+ t.max = 0;
+ }
+}
+
+static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
+{
+ loff_t *spos = v;
+
+ if (*ppos < t.count) {
+ *spos = *spos + 1;
+ *ppos = *spos;
+ return spos;
+ }
+
+ return NULL;
+}
+
+static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
+{
+ struct kmem_cache_node *n;
+ struct kmem_cache *s;
+ enum track_item alloc;
+ int node;
+ loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL);
+
+ s = seq->file->f_inode->i_private;
+
+ if (!spos)
+ return NULL;
+
+ if (*ppos == 0) {
+
+ t.count = 0;
+ t.max = 0;
+ t.loc = NULL;
+ if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_traces") == 0)
+ alloc = TRACK_ALLOC;
+ else
+ alloc = TRACK_FREE;
+
+ if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
+ GFP_KERNEL)) {
+ seq_puts(seq, "Out of memory\n");
+ kfree(spos);
+ return ERR_PTR(-ENOMEM);
+ }
+ /* Push back cpu slabs */
+ flush_all(s);
+
+ for_each_kmem_cache_node(s, node, n) {
+ unsigned long flags;
+ struct page *page;
+
+ if (!atomic_long_read(&n->nr_slabs))
+ continue;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, slab_list)
+ process_slab(&t, s, page, alloc);
+ list_for_each_entry(page, &n->full, slab_list)
+ process_slab(&t, s, page, alloc);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ }
+ }
+
+ if (*ppos < t.count) {
+ *spos = *ppos;
+ return spos;
+ }
+
+ kfree(spos);
+ return NULL;
+}
+
+static const struct seq_operations slab_debugfs_sops = {
+ .start = slab_debugfs_start,
+ .next = slab_debugfs_next,
+ .stop = slab_debugfs_stop,
+ .show = slab_debugfs_show
+};
+DEFINE_SEQ_ATTRIBUTE(slab_debugfs);
+
+static void debugfs_slab_add(struct kmem_cache *s)
+{
+ const char *name;
+ struct dentry *slab_cache_dir;
+ int unmergeable = slab_unmergeable(s);
+
+ if (unlikely(!slab_debugfs_root))
+ return;
+
+ if (!unmergeable && disable_higher_order_debug &&
+ (slub_debug & DEBUG_METADATA_FLAGS))
+ unmergeable = 1;
+
+ if (unmergeable) {
+ /*
+ * Slabcache can never be merged so we can use the name proper.
+ * This is typically the case for debug situations. In that
+ * case we can catch duplicate names easily.
+ */
+ slab_cache_dir = debugfs_lookup(s->name, slab_debugfs_root);
+ debugfs_remove_recursive(slab_cache_dir);
+ name = s->name;
+ } else {
+ /*
+ * Create a unique name for the slab as a target
+ * for the symlinks.
+ */
+ name = create_unique_id(s);
+ }
+
+ slab_cache_dir = debugfs_create_dir(name, slab_debugfs_root);
+
+ debugfs_create_file("alloc_traces", 0400,
+ slab_cache_dir, s, &slab_debugfs_fops);
+
+ debugfs_create_file("free_traces", 0400,
+ slab_cache_dir, s, &slab_debugfs_fops);
+}
+
+void debugfs_slab_release(struct kmem_cache *s)
+{
+ debugfs_remove_recursive(debugfs_lookup(s->name,
+ slab_debugfs_root));
+}
+
+static int __init slab_debugfs_init(void)
+{
+ struct kmem_cache *s;
+
+ slab_debugfs_root = debugfs_create_dir("slab", NULL);
+
+ list_for_each_entry(s, &slab_caches, list)
+ if (s->flags & SLAB_STORE_USER)
+ debugfs_slab_add(s);
+
+ return 0;
+
+}
+__initcall(slab_debugfs_init);
+#endif
/*
* The /proc/slabinfo ABI
*/
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
Hi Faiyaz,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v5.13-rc4]
[cannot apply to hnaz-linux-mm/master next-20210601]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c2131f7e73c9e9365613e323d65c7b9e5b910f56
config: i386-tinyconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/9540acc4691d680b7124d8daa1a2eb98a97ee19a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
git checkout 9540acc4691d680b7124d8daa1a2eb98a97ee19a
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
mm/slab_common.c: In function 'slab_caches_to_rcu_destroy_workfn':
>> mm/slab_common.c:452:3: error: implicit declaration of function 'debugfs_slab_release' [-Werror=implicit-function-declaration]
452 | debugfs_slab_release(s);
| ^~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
vim +/debugfs_slab_release +452 mm/slab_common.c
427
428 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
429 {
430 LIST_HEAD(to_destroy);
431 struct kmem_cache *s, *s2;
432
433 /*
434 * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
435 * @slab_caches_to_rcu_destroy list. The slab pages are freed
436 * through RCU and the associated kmem_cache are dereferenced
437 * while freeing the pages, so the kmem_caches should be freed only
438 * after the pending RCU operations are finished. As rcu_barrier()
439 * is a pretty slow operation, we batch all pending destructions
440 * asynchronously.
441 */
442 mutex_lock(&slab_mutex);
443 list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
444 mutex_unlock(&slab_mutex);
445
446 if (list_empty(&to_destroy))
447 return;
448
449 rcu_barrier();
450
451 list_for_each_entry_safe(s, s2, &to_destroy, list) {
> 452 debugfs_slab_release(s);
453 kfence_shutdown_cache(s);
454 #ifdef SLAB_SUPPORTS_SYSFS
455 sysfs_slab_release(s);
456 #else
457 slab_kmem_cache_release(s);
458 #endif
459 }
460 }
461
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
On 6/1/2021 5:44 PM, Vlastimil Babka wrote:
> On 6/1/21 1:08 PM, kernel test robot wrote:
>> Hi Faiyaz,
>>
>> Thank you for the patch! Yet something to improve:
>>
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on v5.13-rc4]
>> [cannot apply to hnaz-linux-mm/master next-20210601]
>> [If your patch is applied to the wrong git tree, kindly drop us a note.
>> And when submitting patch, we suggest to use '--base' as documented in
>> https://git-scm.com/docs/git-format-patch]
>>
>> url: https://github.com/0day-ci/linux/commits/Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
>> base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c2131f7e73c9e9365613e323d65c7b9e5b910f56
>> config: i386-tinyconfig (attached as .config)
>> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
>> reproduce (this is a W=1 build):
>> # https://github.com/0day-ci/linux/commit/9540acc4691d680b7124d8daa1a2eb98a97ee19a
>> git remote add linux-review https://github.com/0day-ci/linux
>> git fetch --no-tags linux-review Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
>> git checkout 9540acc4691d680b7124d8daa1a2eb98a97ee19a
>> # save the attached .config to linux build tree
>> make W=1 ARCH=i386
>>
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot <[email protected]>
>>
>> All errors (new ones prefixed by >>):
>>
>> mm/slab_common.c: In function 'slab_caches_to_rcu_destroy_workfn':
>>>> mm/slab_common.c:452:3: error: implicit declaration of function 'debugfs_slab_release' [-Werror=implicit-function-declaration]
>> 452 | debugfs_slab_release(s);
>> | ^~~~~~~~~~~~~~~~~~~~
>> cc1: some warnings being treated as errors
>
> Oh, right, CONFIG_SLOB.
> How about moving the ifdef-ed declaration from slub-def.h to mm/slab.h and
> discarding the slab-def.h empty one. That will take care of SLOB too.
>
Yes, doing the same.
>> vim +/debugfs_slab_release +452 mm/slab_common.c
>>
>> 427
>> 428 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
>> 429 {
>> 430 LIST_HEAD(to_destroy);
>> 431 struct kmem_cache *s, *s2;
>> 432
>> 433 /*
>> 434 * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
>> 435 * @slab_caches_to_rcu_destroy list. The slab pages are freed
>> 436 * through RCU and the associated kmem_cache are dereferenced
>> 437 * while freeing the pages, so the kmem_caches should be freed only
>> 438 * after the pending RCU operations are finished. As rcu_barrier()
>> 439 * is a pretty slow operation, we batch all pending destructions
>> 440 * asynchronously.
>> 441 */
>> 442 mutex_lock(&slab_mutex);
>> 443 list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
>> 444 mutex_unlock(&slab_mutex);
>> 445
>> 446 if (list_empty(&to_destroy))
>> 447 return;
>> 448
>> 449 rcu_barrier();
>> 450
>> 451 list_for_each_entry_safe(s, s2, &to_destroy, list) {
>> > 452 debugfs_slab_release(s);
>> 453 kfence_shutdown_cache(s);
>> 454 #ifdef SLAB_SUPPORTS_SYSFS
>> 455 sysfs_slab_release(s);
>> 456 #else
>> 457 slab_kmem_cache_release(s);
>> 458 #endif
>> 459 }
>> 460 }
>> 461
>>
>> ---
>> 0-DAY CI Kernel Test Service, Intel Corporation
>> https://lists.01.org/hyperkitty/list/[email protected]
>>
>
On 6/1/21 1:08 PM, kernel test robot wrote:
> Hi Faiyaz,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on v5.13-rc4]
> [cannot apply to hnaz-linux-mm/master next-20210601]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
>
> url: https://github.com/0day-ci/linux/commits/Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
> base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c2131f7e73c9e9365613e323d65c7b9e5b910f56
> config: i386-tinyconfig (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> # https://github.com/0day-ci/linux/commit/9540acc4691d680b7124d8daa1a2eb98a97ee19a
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
> git checkout 9540acc4691d680b7124d8daa1a2eb98a97ee19a
> # save the attached .config to linux build tree
> make W=1 ARCH=i386
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <[email protected]>
>
> All errors (new ones prefixed by >>):
>
> mm/slab_common.c: In function 'slab_caches_to_rcu_destroy_workfn':
>>> mm/slab_common.c:452:3: error: implicit declaration of function 'debugfs_slab_release' [-Werror=implicit-function-declaration]
> 452 | debugfs_slab_release(s);
> | ^~~~~~~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
Oh, right, CONFIG_SLOB.
How about moving the ifdef-ed declaration from slub-def.h to mm/slab.h and
discarding the slab-def.h empty one. That will take care of SLOB too.
> vim +/debugfs_slab_release +452 mm/slab_common.c
>
> 427
> 428 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
> 429 {
> 430 LIST_HEAD(to_destroy);
> 431 struct kmem_cache *s, *s2;
> 432
> 433 /*
> 434 * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
> 435 * @slab_caches_to_rcu_destroy list. The slab pages are freed
> 436 * through RCU and the associated kmem_cache are dereferenced
> 437 * while freeing the pages, so the kmem_caches should be freed only
> 438 * after the pending RCU operations are finished. As rcu_barrier()
> 439 * is a pretty slow operation, we batch all pending destructions
> 440 * asynchronously.
> 441 */
> 442 mutex_lock(&slab_mutex);
> 443 list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
> 444 mutex_unlock(&slab_mutex);
> 445
> 446 if (list_empty(&to_destroy))
> 447 return;
> 448
> 449 rcu_barrier();
> 450
> 451 list_for_each_entry_safe(s, s2, &to_destroy, list) {
> > 452 debugfs_slab_release(s);
> 453 kfence_shutdown_cache(s);
> 454 #ifdef SLAB_SUPPORTS_SYSFS
> 455 sysfs_slab_release(s);
> 456 #else
> 457 slab_kmem_cache_release(s);
> 458 #endif
> 459 }
> 460 }
> 461
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/[email protected]
>
On 6/1/21 12:07 PM, Faiyaz Mohammed wrote:
> alloc_calls and free_calls implementation in sysfs have two issues,
> one is PAGE_SIZE limitiation of sysfs and other is it does not adhere
> to "one value per file" rule.
>
> To overcome this issues, move the alloc_calls and free_calls implemeation
> to debugfs.
>
> Debugfs cache will be created if SLAB_STORE_USER flag is set.
>
> Rename the alloc_calls/free_calls to alloc_traces/free_traces,
> to be inline with what it does.
>
> Signed-off-by: Faiyaz Mohammed <[email protected]>
When reading the files I'm getting dmesg errors like this:
[ 37.998152] seq_file: buggy .next function slab_debugfs_next did not update
position index
Don't recall this from previous versions?
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index a4a5714..ca39e84 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -449,6 +449,7 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
> rcu_barrier();
>
> list_for_each_entry_safe(s, s2, &to_destroy, list) {
> + debugfs_slab_release(s);
You should remove this one, you already do the release when queueing the work
below. This is not like sysfs where we distinguish _unlink() when queueing and
_release when processing the work.
> +static struct dentry *slab_debugfs_root;
> +struct loc_track t = { 0, 0, NULL };
Ooops, this can't be a global variable, especially when shared without any lock
protection - but even with a protection it would be very suboptimal. You'll need
to make it a seq_file private, see e.g. here for an example:
https://lore.kernel.org/linux-mm/[email protected]/
> static void free_loc_track(struct loc_track *t)
> {
> if (t->max)
> @@ -4825,82 +4840,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
> add_location(t, s, get_track(s, p, alloc));
> put_map(map);
> }
> -
> -static int list_locations(struct kmem_cache *s, char *buf,
> - enum track_item alloc)
> -{
> - int len = 0;
> - unsigned long i;
> - struct loc_track t = { 0, 0, NULL };
> - int node;
> - struct kmem_cache_node *n;
> -
> - if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
> - GFP_KERNEL)) {
> - return sysfs_emit(buf, "Out of memory\n");
> - }
> - /* Push back cpu slabs */
> - flush_all(s);
> -
> - for_each_kmem_cache_node(s, node, n) {
> - unsigned long flags;
> - struct page *page;
> -
> - if (!atomic_long_read(&n->nr_slabs))
> - continue;
> -
> - spin_lock_irqsave(&n->list_lock, flags);
> - list_for_each_entry(page, &n->partial, slab_list)
> - process_slab(&t, s, page, alloc);
> - list_for_each_entry(page, &n->full, slab_list)
> - process_slab(&t, s, page, alloc);
> - spin_unlock_irqrestore(&n->list_lock, flags);
> - }
> -
> - for (i = 0; i < t.count; i++) {
> - struct location *l = &t.loc[i];
> -
> - len += sysfs_emit_at(buf, len, "%7ld ", l->count);
> -
> - if (l->addr)
> - len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr);
> - else
> - len += sysfs_emit_at(buf, len, "<not-available>");
> -
> - if (l->sum_time != l->min_time)
> - len += sysfs_emit_at(buf, len, " age=%ld/%ld/%ld",
> - l->min_time,
> - (long)div_u64(l->sum_time,
> - l->count),
> - l->max_time);
> - else
> - len += sysfs_emit_at(buf, len, " age=%ld", l->min_time);
> -
> - if (l->min_pid != l->max_pid)
> - len += sysfs_emit_at(buf, len, " pid=%ld-%ld",
> - l->min_pid, l->max_pid);
> - else
> - len += sysfs_emit_at(buf, len, " pid=%ld",
> - l->min_pid);
> -
> - if (num_online_cpus() > 1 &&
> - !cpumask_empty(to_cpumask(l->cpus)))
> - len += sysfs_emit_at(buf, len, " cpus=%*pbl",
> - cpumask_pr_args(to_cpumask(l->cpus)));
> -
> - if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
> - len += sysfs_emit_at(buf, len, " nodes=%*pbl",
> - nodemask_pr_args(&l->nodes));
> -
> - len += sysfs_emit_at(buf, len, "\n");
> - }
> -
> - free_loc_track(&t);
> - if (!t.count)
> - len += sysfs_emit_at(buf, len, "No data\n");
> -
> - return len;
> -}
> +#endif /* CONFIG_DEBUG_FS */
> #endif /* CONFIG_SLUB_DEBUG */
>
> #ifdef SLUB_RESILIENCY_TEST
> @@ -5350,21 +5290,6 @@ static ssize_t validate_store(struct kmem_cache *s,
> }
> SLAB_ATTR(validate);
>
> -static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
> -{
> - if (!(s->flags & SLAB_STORE_USER))
> - return -ENOSYS;
> - return list_locations(s, buf, TRACK_ALLOC);
> -}
> -SLAB_ATTR_RO(alloc_calls);
> -
> -static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
> -{
> - if (!(s->flags & SLAB_STORE_USER))
> - return -ENOSYS;
> - return list_locations(s, buf, TRACK_FREE);
> -}
> -SLAB_ATTR_RO(free_calls);
> #endif /* CONFIG_SLUB_DEBUG */
>
> #ifdef CONFIG_FAILSLAB
> @@ -5528,8 +5453,6 @@ static struct attribute *slab_attrs[] = {
> &poison_attr.attr,
> &store_user_attr.attr,
> &validate_attr.attr,
> - &alloc_calls_attr.attr,
> - &free_calls_attr.attr,
> #endif
> #ifdef CONFIG_ZONE_DMA
> &cache_dma_attr.attr,
> @@ -5818,6 +5741,203 @@ static int __init slab_sysfs_init(void)
> __initcall(slab_sysfs_init);
> #endif /* CONFIG_SYSFS */
>
> +#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
> +static int slab_debugfs_show(struct seq_file *seq, void *v)
> +{
> +
> + struct location *l;
> + unsigned int idx = *(unsigned int *)v;
> +
> + if (idx < t.count) {
> + l = &t.loc[idx];
> +
> + seq_printf(seq, "%7ld ", l->count);
> +
> + if (l->addr)
> + seq_printf(seq, "%pS", (void *)l->addr);
> + else
> + seq_puts(seq, "<not-available>");
> +
> + if (l->sum_time != l->min_time) {
> + seq_printf(seq, " age=%ld/%ld/%ld",
> + l->min_time,
> + (long)div_u64(l->sum_time, l->count),
> + l->max_time);
> + } else
> + seq_printf(seq, " age=%ld",
> + l->min_time);
> +
> + if (l->min_pid != l->max_pid)
> + seq_printf(seq, " pid=%ld-%ld",
> + l->min_pid, l->max_pid);
> + else
> + seq_printf(seq, " pid=%ld",
> + l->min_pid);
> +
> + if (num_online_cpus() > 1 &&
> + !cpumask_empty(to_cpumask(l->cpus)))
> + seq_printf(seq, " cpus=%*pbl",
> + cpumask_pr_args(to_cpumask(l->cpus)));
> +
> + if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
> + seq_printf(seq, " nodes=%*pbl",
> + nodemask_pr_args(&l->nodes));
> +
> + seq_puts(seq, "\n");
> + }
> +
> + if (t.count == 0)
> + seq_puts(seq, "No data\n");
> +
> + return 0;
> +}
> +
> +static void slab_debugfs_stop(struct seq_file *seq, void *v)
> +{
> + if (!v && t.max) {
> + free_loc_track(&t);
> + t.max = 0;
> + }
> +}
> +
> +static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
> +{
> + loff_t *spos = v;
> +
> + if (*ppos < t.count) {
> + *spos = *spos + 1;
> + *ppos = *spos;
> + return spos;
> + }
> +
> + return NULL;
> +}
> +
> +static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
> +{
> + struct kmem_cache_node *n;
> + struct kmem_cache *s;
> + enum track_item alloc;
> + int node;
> + loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL);
> +
> + s = seq->file->f_inode->i_private;
> +
> + if (!spos)
> + return NULL;
> +
> + if (*ppos == 0) {
> +
> + t.count = 0;
> + t.max = 0;
> + t.loc = NULL;
> + if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_traces") == 0)
> + alloc = TRACK_ALLOC;
> + else
> + alloc = TRACK_FREE;
> +
> + if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
> + GFP_KERNEL)) {
> + seq_puts(seq, "Out of memory\n");
> + kfree(spos);
> + return ERR_PTR(-ENOMEM);
> + }
> + /* Push back cpu slabs */
> + flush_all(s);
> +
> + for_each_kmem_cache_node(s, node, n) {
> + unsigned long flags;
> + struct page *page;
> +
> + if (!atomic_long_read(&n->nr_slabs))
> + continue;
> +
> + spin_lock_irqsave(&n->list_lock, flags);
> + list_for_each_entry(page, &n->partial, slab_list)
> + process_slab(&t, s, page, alloc);
> + list_for_each_entry(page, &n->full, slab_list)
> + process_slab(&t, s, page, alloc);
> + spin_unlock_irqrestore(&n->list_lock, flags);
> + }
> + }
> +
> + if (*ppos < t.count) {
> + *spos = *ppos;
> + return spos;
> + }
> +
> + kfree(spos);
> + return NULL;
> +}
> +
> +static const struct seq_operations slab_debugfs_sops = {
> + .start = slab_debugfs_start,
> + .next = slab_debugfs_next,
> + .stop = slab_debugfs_stop,
> + .show = slab_debugfs_show
> +};
> +DEFINE_SEQ_ATTRIBUTE(slab_debugfs);
> +
> +static void debugfs_slab_add(struct kmem_cache *s)
> +{
> + const char *name;
> + struct dentry *slab_cache_dir;
> + int unmergeable = slab_unmergeable(s);
> +
> + if (unlikely(!slab_debugfs_root))
> + return;
> +
> + if (!unmergeable && disable_higher_order_debug &&
> + (slub_debug & DEBUG_METADATA_FLAGS))
> + unmergeable = 1;
> +
> + if (unmergeable) {
> + /*
> + * Slabcache can never be merged so we can use the name proper.
> + * This is typically the case for debug situations. In that
> + * case we can catch duplicate names easily.
> + */
> + slab_cache_dir = debugfs_lookup(s->name, slab_debugfs_root);
> + debugfs_remove_recursive(slab_cache_dir);
> + name = s->name;
> + } else {
> + /*
> + * Create a unique name for the slab as a target
> + * for the symlinks.
> + */
> + name = create_unique_id(s);
> + }
> +
> + slab_cache_dir = debugfs_create_dir(name, slab_debugfs_root);
> +
> + debugfs_create_file("alloc_traces", 0400,
> + slab_cache_dir, s, &slab_debugfs_fops);
> +
> + debugfs_create_file("free_traces", 0400,
> + slab_cache_dir, s, &slab_debugfs_fops);
> +}
> +
> +void debugfs_slab_release(struct kmem_cache *s)
> +{
> + debugfs_remove_recursive(debugfs_lookup(s->name,
> + slab_debugfs_root));
> +}
> +
> +static int __init slab_debugfs_init(void)
> +{
> + struct kmem_cache *s;
> +
> + slab_debugfs_root = debugfs_create_dir("slab", NULL);
> +
> + list_for_each_entry(s, &slab_caches, list)
> + if (s->flags & SLAB_STORE_USER)
> + debugfs_slab_add(s);
> +
> + return 0;
> +
> +}
> +__initcall(slab_debugfs_init);
> +#endif
> /*
> * The /proc/slabinfo ABI
> */
>
Hi Faiyaz,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v5.13-rc4]
[cannot apply to hnaz-linux-mm/master next-20210601]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c2131f7e73c9e9365613e323d65c7b9e5b910f56
config: x86_64-randconfig-a001-20210601 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project db26cd30b6dd65e88d786e97a1e453af5cd48966)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/9540acc4691d680b7124d8daa1a2eb98a97ee19a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210601-180903
git checkout 9540acc4691d680b7124d8daa1a2eb98a97ee19a
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
>> mm/slab_common.c:452:3: error: implicit declaration of function 'debugfs_slab_release' [-Werror,-Wimplicit-function-declaration]
debugfs_slab_release(s);
^
mm/slab_common.c:473:3: error: implicit declaration of function 'debugfs_slab_release' [-Werror,-Wimplicit-function-declaration]
debugfs_slab_release(s);
^
mm/slab_common.c:481:3: error: implicit declaration of function 'debugfs_slab_release' [-Werror,-Wimplicit-function-declaration]
debugfs_slab_release(s);
^
3 errors generated.
vim +/debugfs_slab_release +452 mm/slab_common.c
427
428 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
429 {
430 LIST_HEAD(to_destroy);
431 struct kmem_cache *s, *s2;
432
433 /*
434 * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
435 * @slab_caches_to_rcu_destroy list. The slab pages are freed
436 * through RCU and the associated kmem_cache are dereferenced
437 * while freeing the pages, so the kmem_caches should be freed only
438 * after the pending RCU operations are finished. As rcu_barrier()
439 * is a pretty slow operation, we batch all pending destructions
440 * asynchronously.
441 */
442 mutex_lock(&slab_mutex);
443 list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
444 mutex_unlock(&slab_mutex);
445
446 if (list_empty(&to_destroy))
447 return;
448
449 rcu_barrier();
450
451 list_for_each_entry_safe(s, s2, &to_destroy, list) {
> 452 debugfs_slab_release(s);
453 kfence_shutdown_cache(s);
454 #ifdef SLAB_SUPPORTS_SYSFS
455 sysfs_slab_release(s);
456 #else
457 slab_kmem_cache_release(s);
458 #endif
459 }
460 }
461
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
On 6/1/2021 7:01 PM, Vlastimil Babka wrote:
> On 6/1/21 12:07 PM, Faiyaz Mohammed wrote:
>> alloc_calls and free_calls implementation in sysfs have two issues,
>> one is PAGE_SIZE limitiation of sysfs and other is it does not adhere
>> to "one value per file" rule.
>>
>> To overcome this issues, move the alloc_calls and free_calls implemeation
>> to debugfs.
>>
>> Debugfs cache will be created if SLAB_STORE_USER flag is set.
>>
>> Rename the alloc_calls/free_calls to alloc_traces/free_traces,
>> to be inline with what it does.
>>
>> Signed-off-by: Faiyaz Mohammed <[email protected]>
>
> When reading the files I'm getting dmesg errors like this:
>
> [ 37.998152] seq_file: buggy .next function slab_debugfs_next did not update
> position index
>
> Don't recall this from previous versions?
>
slab_debugfs_next() is not updating the pos after last read, so it's
retuning null. In fs/seq_file.c if pos is not updated in ->next() fn,
it's printing the above info but I will address this in next patch version.
>> diff --git a/mm/slab_common.c b/mm/slab_common.c
>> index a4a5714..ca39e84 100644
>> --- a/mm/slab_common.c
>> +++ b/mm/slab_common.c
>> @@ -449,6 +449,7 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
>> rcu_barrier();
>>
>> list_for_each_entry_safe(s, s2, &to_destroy, list) {
>> + debugfs_slab_release(s);
>
> You should remove this one, you already do the release when queueing the work
> below. This is not like sysfs where we distinguish _unlink() when queueing and
> _release when processing the work.
>
oh, yes, I will update in next patch version.
>> +static struct dentry *slab_debugfs_root;
>> +struct loc_track t = { 0, 0, NULL };
>
> Ooops, this can't be a global variable, especially when shared without any lock
> protection - but even with a protection it would be very suboptimal. You'll need
> to make it a seq_file private, see e.g. here for an example:
> https://lore.kernel.org/linux-mm/[email protected]/
>
I will address this in next patch version.
>> static void free_loc_track(struct loc_track *t)
>> {
>> if (t->max)
>> @@ -4825,82 +4840,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
>> add_location(t, s, get_track(s, p, alloc));
>> put_map(map);
>> }
>> -
>> -static int list_locations(struct kmem_cache *s, char *buf,
>> - enum track_item alloc)
>> -{
>> - int len = 0;
>> - unsigned long i;
>> - struct loc_track t = { 0, 0, NULL };
>> - int node;
>> - struct kmem_cache_node *n;
>> -
>> - if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
>> - GFP_KERNEL)) {
>> - return sysfs_emit(buf, "Out of memory\n");
>> - }
>> - /* Push back cpu slabs */
>> - flush_all(s);
>> -
>> - for_each_kmem_cache_node(s, node, n) {
>> - unsigned long flags;
>> - struct page *page;
>> -
>> - if (!atomic_long_read(&n->nr_slabs))
>> - continue;
>> -
>> - spin_lock_irqsave(&n->list_lock, flags);
>> - list_for_each_entry(page, &n->partial, slab_list)
>> - process_slab(&t, s, page, alloc);
>> - list_for_each_entry(page, &n->full, slab_list)
>> - process_slab(&t, s, page, alloc);
>> - spin_unlock_irqrestore(&n->list_lock, flags);
>> - }
>> -
>> - for (i = 0; i < t.count; i++) {
>> - struct location *l = &t.loc[i];
>> -
>> - len += sysfs_emit_at(buf, len, "%7ld ", l->count);
>> -
>> - if (l->addr)
>> - len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr);
>> - else
>> - len += sysfs_emit_at(buf, len, "<not-available>");
>> -
>> - if (l->sum_time != l->min_time)
>> - len += sysfs_emit_at(buf, len, " age=%ld/%ld/%ld",
>> - l->min_time,
>> - (long)div_u64(l->sum_time,
>> - l->count),
>> - l->max_time);
>> - else
>> - len += sysfs_emit_at(buf, len, " age=%ld", l->min_time);
>> -
>> - if (l->min_pid != l->max_pid)
>> - len += sysfs_emit_at(buf, len, " pid=%ld-%ld",
>> - l->min_pid, l->max_pid);
>> - else
>> - len += sysfs_emit_at(buf, len, " pid=%ld",
>> - l->min_pid);
>> -
>> - if (num_online_cpus() > 1 &&
>> - !cpumask_empty(to_cpumask(l->cpus)))
>> - len += sysfs_emit_at(buf, len, " cpus=%*pbl",
>> - cpumask_pr_args(to_cpumask(l->cpus)));
>> -
>> - if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
>> - len += sysfs_emit_at(buf, len, " nodes=%*pbl",
>> - nodemask_pr_args(&l->nodes));
>> -
>> - len += sysfs_emit_at(buf, len, "\n");
>> - }
>> -
>> - free_loc_track(&t);
>> - if (!t.count)
>> - len += sysfs_emit_at(buf, len, "No data\n");
>> -
>> - return len;
>> -}
>> +#endif /* CONFIG_DEBUG_FS */
>> #endif /* CONFIG_SLUB_DEBUG */
>>
>> #ifdef SLUB_RESILIENCY_TEST
>> @@ -5350,21 +5290,6 @@ static ssize_t validate_store(struct kmem_cache *s,
>> }
>> SLAB_ATTR(validate);
>>
>> -static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
>> -{
>> - if (!(s->flags & SLAB_STORE_USER))
>> - return -ENOSYS;
>> - return list_locations(s, buf, TRACK_ALLOC);
>> -}
>> -SLAB_ATTR_RO(alloc_calls);
>> -
>> -static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
>> -{
>> - if (!(s->flags & SLAB_STORE_USER))
>> - return -ENOSYS;
>> - return list_locations(s, buf, TRACK_FREE);
>> -}
>> -SLAB_ATTR_RO(free_calls);
>> #endif /* CONFIG_SLUB_DEBUG */
>>
>> #ifdef CONFIG_FAILSLAB
>> @@ -5528,8 +5453,6 @@ static struct attribute *slab_attrs[] = {
>> &poison_attr.attr,
>> &store_user_attr.attr,
>> &validate_attr.attr,
>> - &alloc_calls_attr.attr,
>> - &free_calls_attr.attr,
>> #endif
>> #ifdef CONFIG_ZONE_DMA
>> &cache_dma_attr.attr,
>> @@ -5818,6 +5741,203 @@ static int __init slab_sysfs_init(void)
>> __initcall(slab_sysfs_init);
>> #endif /* CONFIG_SYSFS */
>>
>> +#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
>> +static int slab_debugfs_show(struct seq_file *seq, void *v)
>> +{
>> +
>> + struct location *l;
>> + unsigned int idx = *(unsigned int *)v;
>> +
>> + if (idx < t.count) {
>> + l = &t.loc[idx];
>> +
>> + seq_printf(seq, "%7ld ", l->count);
>> +
>> + if (l->addr)
>> + seq_printf(seq, "%pS", (void *)l->addr);
>> + else
>> + seq_puts(seq, "<not-available>");
>> +
>> + if (l->sum_time != l->min_time) {
>> + seq_printf(seq, " age=%ld/%ld/%ld",
>> + l->min_time,
>> + (long)div_u64(l->sum_time, l->count),
>> + l->max_time);
>> + } else
>> + seq_printf(seq, " age=%ld",
>> + l->min_time);
>> +
>> + if (l->min_pid != l->max_pid)
>> + seq_printf(seq, " pid=%ld-%ld",
>> + l->min_pid, l->max_pid);
>> + else
>> + seq_printf(seq, " pid=%ld",
>> + l->min_pid);
>> +
>> + if (num_online_cpus() > 1 &&
>> + !cpumask_empty(to_cpumask(l->cpus)))
>> + seq_printf(seq, " cpus=%*pbl",
>> + cpumask_pr_args(to_cpumask(l->cpus)));
>> +
>> + if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
>> + seq_printf(seq, " nodes=%*pbl",
>> + nodemask_pr_args(&l->nodes));
>> +
>> + seq_puts(seq, "\n");
>> + }
>> +
>> + if (t.count == 0)
>> + seq_puts(seq, "No data\n");
>> +
>> + return 0;
>> +}
>> +
>> +static void slab_debugfs_stop(struct seq_file *seq, void *v)
>> +{
>> + if (!v && t.max) {
>> + free_loc_track(&t);
>> + t.max = 0;
>> + }
>> +}
>> +
>> +static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
>> +{
>> + loff_t *spos = v;
>> +
>> + if (*ppos < t.count) {
>> + *spos = *spos + 1;
>> + *ppos = *spos;
>> + return spos;
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> +static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
>> +{
>> + struct kmem_cache_node *n;
>> + struct kmem_cache *s;
>> + enum track_item alloc;
>> + int node;
>> + loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL);
>> +
>> + s = seq->file->f_inode->i_private;
>> +
>> + if (!spos)
>> + return NULL;
>> +
>> + if (*ppos == 0) {
>> +
>> + t.count = 0;
>> + t.max = 0;
>> + t.loc = NULL;
>> + if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_traces") == 0)
>> + alloc = TRACK_ALLOC;
>> + else
>> + alloc = TRACK_FREE;
>> +
>> + if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
>> + GFP_KERNEL)) {
>> + seq_puts(seq, "Out of memory\n");
>> + kfree(spos);
>> + return ERR_PTR(-ENOMEM);
>> + }
>> + /* Push back cpu slabs */
>> + flush_all(s);
>> +
>> + for_each_kmem_cache_node(s, node, n) {
>> + unsigned long flags;
>> + struct page *page;
>> +
>> + if (!atomic_long_read(&n->nr_slabs))
>> + continue;
>> +
>> + spin_lock_irqsave(&n->list_lock, flags);
>> + list_for_each_entry(page, &n->partial, slab_list)
>> + process_slab(&t, s, page, alloc);
>> + list_for_each_entry(page, &n->full, slab_list)
>> + process_slab(&t, s, page, alloc);
>> + spin_unlock_irqrestore(&n->list_lock, flags);
>> + }
>> + }
>> +
>> + if (*ppos < t.count) {
>> + *spos = *ppos;
>> + return spos;
>> + }
>> +
>> + kfree(spos);
>> + return NULL;
>> +}
>> +
>> +static const struct seq_operations slab_debugfs_sops = {
>> + .start = slab_debugfs_start,
>> + .next = slab_debugfs_next,
>> + .stop = slab_debugfs_stop,
>> + .show = slab_debugfs_show
>> +};
>> +DEFINE_SEQ_ATTRIBUTE(slab_debugfs);
>> +
>> +static void debugfs_slab_add(struct kmem_cache *s)
>> +{
>> + const char *name;
>> + struct dentry *slab_cache_dir;
>> + int unmergeable = slab_unmergeable(s);
>> +
>> + if (unlikely(!slab_debugfs_root))
>> + return;
>> +
>> + if (!unmergeable && disable_higher_order_debug &&
>> + (slub_debug & DEBUG_METADATA_FLAGS))
>> + unmergeable = 1;
>> +
>> + if (unmergeable) {
>> + /*
>> + * Slabcache can never be merged so we can use the name proper.
>> + * This is typically the case for debug situations. In that
>> + * case we can catch duplicate names easily.
>> + */
>> + slab_cache_dir = debugfs_lookup(s->name, slab_debugfs_root);
>> + debugfs_remove_recursive(slab_cache_dir);
>> + name = s->name;
>> + } else {
>> + /*
>> + * Create a unique name for the slab as a target
>> + * for the symlinks.
>> + */
>> + name = create_unique_id(s);
>> + }
>> +
>> + slab_cache_dir = debugfs_create_dir(name, slab_debugfs_root);
>> +
>> + debugfs_create_file("alloc_traces", 0400,
>> + slab_cache_dir, s, &slab_debugfs_fops);
>> +
>> + debugfs_create_file("free_traces", 0400,
>> + slab_cache_dir, s, &slab_debugfs_fops);
>> +}
>> +
>> +void debugfs_slab_release(struct kmem_cache *s)
>> +{
>> + debugfs_remove_recursive(debugfs_lookup(s->name,
>> + slab_debugfs_root));
>> +}
>> +
>> +static int __init slab_debugfs_init(void)
>> +{
>> + struct kmem_cache *s;
>> +
>> + slab_debugfs_root = debugfs_create_dir("slab", NULL);
>> +
>> + list_for_each_entry(s, &slab_caches, list)
>> + if (s->flags & SLAB_STORE_USER)
>> + debugfs_slab_add(s);
>> +
>> + return 0;
>> +
>> +}
>> +__initcall(slab_debugfs_init);
>> +#endif
>> /*
>> * The /proc/slabinfo ABI
>> */
>>
>