2019-03-18 09:48:48

by Kirill Tkhai

[permalink] [raw]
Subject: [PATCH REBASED 0/4] mm: Generalize putback functions

(This is resending of the patchset, rebased on next-20190318).

Functions putback_inactive_pages() and move_active_pages_to_lru()
are almost similar, so this patchset merges them in only function.

v3: Replace list_del_init() with list_del()
v2.5: Update comment
v2: Fix tracing. Return VM_BUG_ON() check on the old place. Improve spelling.
---

Kirill Tkhai (4):
mm: Move recent_rotated pages calculation to shrink_inactive_list()
mm: Move nr_deactivate accounting to shrink_active_list()
mm: Remove pages_to_free argument of move_active_pages_to_lru()
mm: Generalize putback scan functions


.../trace/postprocess/trace-vmscan-postprocess.pl | 7 +
include/linux/vmstat.h | 2
include/trace/events/vmscan.h | 13 +-
mm/vmscan.c | 148 +++++++-------------
4 files changed, 68 insertions(+), 102 deletions(-)

--
Signed-off-by: Kirill Tkhai <[email protected]>
Reviewed-by: Daniel Jordan <[email protected]>


2019-03-18 09:30:00

by Kirill Tkhai

[permalink] [raw]
Subject: [PATCH REBASED 2/4] mm: Move nr_deactivate accounting to shrink_active_list()

We know which LRU is not active.

Signed-off-by: Kirill Tkhai <[email protected]>
Reviewed-by: Daniel Jordan <[email protected]>
---
mm/vmscan.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index e610737b36df..d2adabe4457d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2040,12 +2040,6 @@ static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
}
}

- if (!is_active_lru(lru)) {
- __count_vm_events(PGDEACTIVATE, nr_moved);
- count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE,
- nr_moved);
- }
-
return nr_moved;
}

@@ -2137,6 +2131,10 @@ static void shrink_active_list(unsigned long nr_to_scan,

nr_activate = move_active_pages_to_lru(lruvec, &l_active, &l_hold, lru);
nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, &l_hold, lru - LRU_ACTIVE);
+
+ __count_vm_events(PGDEACTIVATE, nr_deactivate);
+ __count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate);
+
__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);
spin_unlock_irq(&pgdat->lru_lock);



2019-03-18 09:31:05

by Kirill Tkhai

[permalink] [raw]
Subject: [PATCH REBASED 4/4] mm: Generalize putback scan functions

This combines two similar functions move_active_pages_to_lru()
and putback_inactive_pages() into single move_pages_to_lru().
This remove duplicate code and makes object file size smaller.

Before:
text data bss dec hex filename
57082 4732 128 61942 f1f6 mm/vmscan.o
After:
text data bss dec hex filename
55112 4600 128 59840 e9c0 mm/vmscan.o

Note, that now we are checking for !page_evictable() coming
from shrink_active_list(), which shouldn't change any behavior
since that path works with evictable pages only.

Signed-off-by: Kirill Tkhai <[email protected]>
Reviewed-by: Daniel Jordan <[email protected]>

v3: Replace list_del_init() with list_del()
v2: Move VM_BUG_ON() up.
---
mm/vmscan.c | 122 +++++++++++++++++++----------------------------------------
1 file changed, 40 insertions(+), 82 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1794ec7b21d8..f6b9b45f731d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1807,33 +1807,53 @@ static int too_many_isolated(struct pglist_data *pgdat, int file,
return isolated > inactive;
}

-static noinline_for_stack void
-putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
+/*
+ * This moves pages from @list to corresponding LRU list.
+ *
+ * We move them the other way if the page is referenced by one or more
+ * processes, from rmap.
+ *
+ * If the pages are mostly unmapped, the processing is fast and it is
+ * appropriate to hold zone_lru_lock across the whole operation. But if
+ * the pages are mapped, the processing is slow (page_referenced()) so we
+ * should drop zone_lru_lock around each page. It's impossible to balance
+ * this, so instead we remove the pages from the LRU while processing them.
+ * It is safe to rely on PG_active against the non-LRU pages in here because
+ * nobody will play with that bit on a non-LRU page.
+ *
+ * The downside is that we have to touch page->_refcount against each page.
+ * But we had to alter page->flags anyway.
+ *
+ * Returns the number of pages moved to the given lruvec.
+ */
+
+static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
+ struct list_head *list)
{
struct pglist_data *pgdat = lruvec_pgdat(lruvec);
+ int nr_pages, nr_moved = 0;
LIST_HEAD(pages_to_free);
+ struct page *page;
+ enum lru_list lru;

- /*
- * Put back any unfreeable pages.
- */
- while (!list_empty(page_list)) {
- struct page *page = lru_to_page(page_list);
- int lru;
-
+ while (!list_empty(list)) {
+ page = lru_to_page(list);
VM_BUG_ON_PAGE(PageLRU(page), page);
- list_del(&page->lru);
if (unlikely(!page_evictable(page))) {
+ list_del(&page->lru);
spin_unlock_irq(&pgdat->lru_lock);
putback_lru_page(page);
spin_lock_irq(&pgdat->lru_lock);
continue;
}
-
lruvec = mem_cgroup_page_lruvec(page, pgdat);

SetPageLRU(page);
lru = page_lru(page);
- add_page_to_lru_list(page, lruvec, lru);
+
+ nr_pages = hpage_nr_pages(page);
+ update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
+ list_move(&page->lru, &lruvec->lists[lru]);

if (put_page_testzero(page)) {
__ClearPageLRU(page);
@@ -1847,13 +1867,17 @@ putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
spin_lock_irq(&pgdat->lru_lock);
} else
list_add(&page->lru, &pages_to_free);
+ } else {
+ nr_moved += nr_pages;
}
}

/*
* To save our caller's stack, now use input list for pages to free.
*/
- list_splice(&pages_to_free, page_list);
+ list_splice(&pages_to_free, list);
+
+ return nr_moved;
}

/*
@@ -1945,7 +1969,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
reclaim_stat->recent_rotated[1] = stat.nr_activate[1];

- putback_inactive_pages(lruvec, &page_list);
+ move_pages_to_lru(lruvec, &page_list);

__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);

@@ -1982,72 +2006,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
return nr_reclaimed;
}

-/*
- * This moves pages from the active list to the inactive list.
- *
- * We move them the other way if the page is referenced by one or more
- * processes, from rmap.
- *
- * If the pages are mostly unmapped, the processing is fast and it is
- * appropriate to hold pgdat->lru_lock across the whole operation. But if
- * the pages are mapped, the processing is slow (page_referenced()) so we
- * should drop pgdat->lru_lock around each page. It's impossible to balance
- * this, so instead we remove the pages from the LRU while processing them.
- * It is safe to rely on PG_active against the non-LRU pages in here because
- * nobody will play with that bit on a non-LRU page.
- *
- * The downside is that we have to touch page->_refcount against each page.
- * But we had to alter page->flags anyway.
- *
- * Returns the number of pages moved to the given lru.
- */
-
-static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
- struct list_head *list,
- enum lru_list lru)
-{
- struct pglist_data *pgdat = lruvec_pgdat(lruvec);
- LIST_HEAD(pages_to_free);
- struct page *page;
- int nr_pages;
- int nr_moved = 0;
-
- while (!list_empty(list)) {
- page = lru_to_page(list);
- lruvec = mem_cgroup_page_lruvec(page, pgdat);
-
- VM_BUG_ON_PAGE(PageLRU(page), page);
- SetPageLRU(page);
-
- nr_pages = hpage_nr_pages(page);
- update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
- list_move(&page->lru, &lruvec->lists[lru]);
-
- if (put_page_testzero(page)) {
- __ClearPageLRU(page);
- __ClearPageActive(page);
- del_page_from_lru_list(page, lruvec, lru);
-
- if (unlikely(PageCompound(page))) {
- spin_unlock_irq(&pgdat->lru_lock);
- mem_cgroup_uncharge(page);
- (*get_compound_page_dtor(page))(page);
- spin_lock_irq(&pgdat->lru_lock);
- } else
- list_add(&page->lru, &pages_to_free);
- } else {
- nr_moved += nr_pages;
- }
- }
-
- /*
- * To save our caller's stack, now use input list for pages to free.
- */
- list_splice(&pages_to_free, list);
-
- return nr_moved;
-}
-
static void shrink_active_list(unsigned long nr_to_scan,
struct lruvec *lruvec,
struct scan_control *sc,
@@ -2134,8 +2092,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
*/
reclaim_stat->recent_rotated[file] += nr_rotated;

- nr_activate = move_active_pages_to_lru(lruvec, &l_active, lru);
- nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, lru - LRU_ACTIVE);
+ nr_activate = move_pages_to_lru(lruvec, &l_active);
+ nr_deactivate = move_pages_to_lru(lruvec, &l_inactive);
/* Keep all free pages in l_active list */
list_splice(&l_inactive, &l_active);



2019-03-18 09:48:15

by Kirill Tkhai

[permalink] [raw]
Subject: [PATCH REBASED 3/4] mm: Remove pages_to_free argument of move_active_pages_to_lru()

We may use input argument list as output argument too.
This makes the function more similar to putback_inactive_pages().

Signed-off-by: Kirill Tkhai <[email protected]>
Reviewed-by: Daniel Jordan <[email protected]>

v2: Fix comment spelling.
---
mm/vmscan.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d2adabe4457d..1794ec7b21d8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2004,10 +2004,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,

static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
struct list_head *list,
- struct list_head *pages_to_free,
enum lru_list lru)
{
struct pglist_data *pgdat = lruvec_pgdat(lruvec);
+ LIST_HEAD(pages_to_free);
struct page *page;
int nr_pages;
int nr_moved = 0;
@@ -2034,12 +2034,17 @@ static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
(*get_compound_page_dtor(page))(page);
spin_lock_irq(&pgdat->lru_lock);
} else
- list_add(&page->lru, pages_to_free);
+ list_add(&page->lru, &pages_to_free);
} else {
nr_moved += nr_pages;
}
}

+ /*
+ * To save our caller's stack, now use input list for pages to free.
+ */
+ list_splice(&pages_to_free, list);
+
return nr_moved;
}

@@ -2129,8 +2134,10 @@ static void shrink_active_list(unsigned long nr_to_scan,
*/
reclaim_stat->recent_rotated[file] += nr_rotated;

- nr_activate = move_active_pages_to_lru(lruvec, &l_active, &l_hold, lru);
- nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, &l_hold, lru - LRU_ACTIVE);
+ nr_activate = move_active_pages_to_lru(lruvec, &l_active, lru);
+ nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, lru - LRU_ACTIVE);
+ /* Keep all free pages in l_active list */
+ list_splice(&l_inactive, &l_active);

__count_vm_events(PGDEACTIVATE, nr_deactivate);
__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate);
@@ -2138,8 +2145,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);
spin_unlock_irq(&pgdat->lru_lock);

- mem_cgroup_uncharge_list(&l_hold);
- free_unref_page_list(&l_hold);
+ mem_cgroup_uncharge_list(&l_active);
+ free_unref_page_list(&l_active);
trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_taken, nr_activate,
nr_deactivate, nr_rotated, sc->priority, file);
}


2019-03-18 09:48:45

by Kirill Tkhai

[permalink] [raw]
Subject: [PATCH REBASED 1/4] mm: Move recent_rotated pages calculation to shrink_inactive_list()

The patch moves the calculation from putback_inactive_pages()
to shrink_inactive_list(). This makes putback_inactive_pages()
looking more similar to move_active_pages_to_lru().

To do that, we account activated pages in reclaim_stat::nr_activate.
Since a page may change its LRU type from anon to file cache
inside shrink_page_list() (see ClearPageSwapBacked()), we have to
account pages for the both types. So, nr_activate becomes an array.

Previously we used nr_activate to account PGACTIVATE events, but now
we account them into pgactivate variable (since they are about
number of pages in general, not about sum of hpage_nr_pages).

Signed-off-by: Kirill Tkhai <[email protected]>
Reviewed-by: Daniel Jordan <[email protected]>

v2.5: Update comment.
v2: Update trace events.
---
.../trace/postprocess/trace-vmscan-postprocess.pl | 7 ++++---
include/linux/vmstat.h | 2 +-
include/trace/events/vmscan.h | 13 ++++++++-----
mm/vmscan.c | 15 +++++++--------
4 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
index 66bfd8396877..995da15b16ca 100644
--- a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
+++ b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
@@ -113,7 +113,7 @@ my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)';
my $regex_kswapd_sleep_default = 'nid=([0-9]*)';
my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*) gfp_flags=([A-Z_|]*)';
my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) classzone_idx=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_skipped=([0-9]*) nr_taken=([0-9]*) lru=([a-z_]*)';
-my $regex_lru_shrink_inactive_default = 'nid=([0-9]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) nr_dirty=([0-9]*) nr_writeback=([0-9]*) nr_congested=([0-9]*) nr_immediate=([0-9]*) nr_activate=([0-9]*) nr_ref_keep=([0-9]*) nr_unmap_fail=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)';
+my $regex_lru_shrink_inactive_default = 'nid=([0-9]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) nr_dirty=([0-9]*) nr_writeback=([0-9]*) nr_congested=([0-9]*) nr_immediate=([0-9]*) nr_activate_anon=([0-9]*) nr_activate_file=([0-9]*) nr_ref_keep=([0-9]*) nr_unmap_fail=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)';
my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)';
my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)';

@@ -212,7 +212,8 @@ $regex_lru_shrink_inactive = generate_traceevent_regex(
"vmscan/mm_vmscan_lru_shrink_inactive",
$regex_lru_shrink_inactive_default,
"nid", "nr_scanned", "nr_reclaimed", "nr_dirty", "nr_writeback",
- "nr_congested", "nr_immediate", "nr_activate", "nr_ref_keep",
+ "nr_congested", "nr_immediate", "nr_activate_anon",
+ "nr_activate_file", "nr_ref_keep",
"nr_unmap_fail", "priority", "flags");
$regex_lru_shrink_active = generate_traceevent_regex(
"vmscan/mm_vmscan_lru_shrink_active",
@@ -407,7 +408,7 @@ sub process_events {
}

my $nr_reclaimed = $3;
- my $flags = $12;
+ my $flags = $13;
my $file = 0;
if ($flags =~ /RECLAIM_WB_FILE/) {
$file = 1;
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 2db8d60981fe..bdeda4b079fe 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -26,7 +26,7 @@ struct reclaim_stat {
unsigned nr_congested;
unsigned nr_writeback;
unsigned nr_immediate;
- unsigned nr_activate;
+ unsigned nr_activate[2];
unsigned nr_ref_keep;
unsigned nr_unmap_fail;
};
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index a1cb91342231..4f0e45e90cfc 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -358,7 +358,8 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
__field(unsigned long, nr_writeback)
__field(unsigned long, nr_congested)
__field(unsigned long, nr_immediate)
- __field(unsigned long, nr_activate)
+ __field(unsigned int, nr_activate0)
+ __field(unsigned int, nr_activate1)
__field(unsigned long, nr_ref_keep)
__field(unsigned long, nr_unmap_fail)
__field(int, priority)
@@ -373,20 +374,22 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
__entry->nr_writeback = stat->nr_writeback;
__entry->nr_congested = stat->nr_congested;
__entry->nr_immediate = stat->nr_immediate;
- __entry->nr_activate = stat->nr_activate;
+ __entry->nr_activate0 = stat->nr_activate[0];
+ __entry->nr_activate1 = stat->nr_activate[1];
__entry->nr_ref_keep = stat->nr_ref_keep;
__entry->nr_unmap_fail = stat->nr_unmap_fail;
__entry->priority = priority;
__entry->reclaim_flags = trace_shrink_flags(file);
),

- TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate=%ld nr_ref_keep=%ld nr_unmap_fail=%ld priority=%d flags=%s",
+ TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld priority=%d flags=%s",
__entry->nid,
__entry->nr_scanned, __entry->nr_reclaimed,
__entry->nr_dirty, __entry->nr_writeback,
__entry->nr_congested, __entry->nr_immediate,
- __entry->nr_activate, __entry->nr_ref_keep,
- __entry->nr_unmap_fail, __entry->priority,
+ __entry->nr_activate0, __entry->nr_activate1,
+ __entry->nr_ref_keep, __entry->nr_unmap_fail,
+ __entry->priority,
show_reclaim_flags(__entry->reclaim_flags))
);

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 07f74e9507b6..e610737b36df 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1107,6 +1107,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
LIST_HEAD(ret_pages);
LIST_HEAD(free_pages);
unsigned nr_reclaimed = 0;
+ unsigned pgactivate = 0;

memset(stat, 0, sizeof(*stat));
cond_resched();
@@ -1466,8 +1467,10 @@ static unsigned long shrink_page_list(struct list_head *page_list,
try_to_free_swap(page);
VM_BUG_ON_PAGE(PageActive(page), page);
if (!PageMlocked(page)) {
+ int type = page_is_file_cache(page);
SetPageActive(page);
- stat->nr_activate++;
+ pgactivate++;
+ stat->nr_activate[type] += hpage_nr_pages(page);
count_memcg_page_event(page, PGACTIVATE);
}
keep_locked:
@@ -1482,7 +1485,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
free_unref_page_list(&free_pages);

list_splice(&ret_pages, page_list);
- count_vm_events(PGACTIVATE, stat->nr_activate);
+ count_vm_events(PGACTIVATE, pgactivate);

return nr_reclaimed;
}
@@ -1807,7 +1810,6 @@ static int too_many_isolated(struct pglist_data *pgdat, int file,
static noinline_for_stack void
putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
{
- struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
struct pglist_data *pgdat = lruvec_pgdat(lruvec);
LIST_HEAD(pages_to_free);

@@ -1833,11 +1835,6 @@ putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
lru = page_lru(page);
add_page_to_lru_list(page, lruvec, lru);

- if (is_active_lru(lru)) {
- int file = is_file_lru(lru);
- int numpages = hpage_nr_pages(page);
- reclaim_stat->recent_rotated[file] += numpages;
- }
if (put_page_testzero(page)) {
__ClearPageLRU(page);
__ClearPageActive(page);
@@ -1945,6 +1942,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
count_memcg_events(lruvec_memcg(lruvec), PGSTEAL_DIRECT,
nr_reclaimed);
}
+ reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
+ reclaim_stat->recent_rotated[1] = stat.nr_activate[1];

putback_inactive_pages(lruvec, &page_list);



2019-03-22 15:07:34

by Chris Down

[permalink] [raw]
Subject: [PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

"mm: move nr_deactivate accounting to shrink_active_list()" uses the
non-irqsaved version of count_memcg_events (__count_memcg_events), but
we've only exported the irqsaving version of it to userspace, so the
build breaks:

mm/vmscan.c: In function ‘shrink_active_list’:
mm/vmscan.c:2101:2: error: implicit declaration of function ‘__count_memcg_events’; did you mean ‘count_memcg_events’? [-Werror=implicit-function-declaration]

This fixup makes it build with !CONFIG_MEMCG.

Signed-off-by: Chris Down <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
include/linux/memcontrol.h | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 534267947664..b226c4bafc93 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1147,6 +1147,12 @@ static inline void count_memcg_events(struct mem_cgroup *memcg,
{
}

+static inline void __count_memcg_events(struct mem_cgroup *memcg,
+ enum vm_event_item idx,
+ unsigned long count)
+{
+}
+
static inline void count_memcg_page_event(struct page *page,
int idx)
{
--
2.21.0


2019-03-22 15:09:04

by Chris Down

[permalink] [raw]
Subject: Re: [PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

Chris Down writes:
>"mm: move nr_deactivate accounting to shrink_active_list()" uses the
>non-irqsaved version of count_memcg_events (__count_memcg_events), but
>we've only exported the irqsaving version of it to userspace, so the
>build breaks:

Er, "with !CONFIG_MEMCG", not "to userspace". No idea where that came from...

2019-03-22 15:17:56

by Kirill Tkhai

[permalink] [raw]
Subject: Re: [PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

On 22.03.2019 18:05, Chris Down wrote:
> "mm: move nr_deactivate accounting to shrink_active_list()" uses the
> non-irqsaved version of count_memcg_events (__count_memcg_events), but
> we've only exported the irqsaving version of it to userspace, so the
> build breaks:
>
> mm/vmscan.c: In function ‘shrink_active_list’:
> mm/vmscan.c:2101:2: error: implicit declaration of function ‘__count_memcg_events’; did you mean ‘count_memcg_events’? [-Werror=implicit-function-declaration]
>
> This fixup makes it build with !CONFIG_MEMCG.

Yeah, thanks, Chris.

> Signed-off-by: Chris Down <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Kirill Tkhai <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Tejun Heo <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> ---
> include/linux/memcontrol.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 534267947664..b226c4bafc93 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1147,6 +1147,12 @@ static inline void count_memcg_events(struct mem_cgroup *memcg,
> {
> }
>
> +static inline void __count_memcg_events(struct mem_cgroup *memcg,
> + enum vm_event_item idx,
> + unsigned long count)
> +{
> +}
> +
> static inline void count_memcg_page_event(struct page *page,
> int idx)
> {
>

2019-05-28 15:54:09

by Johannes Weiner

[permalink] [raw]
Subject: Re: [PATCH REBASED 1/4] mm: Move recent_rotated pages calculation to shrink_inactive_list()

On Mon, Mar 18, 2019 at 12:27:59PM +0300, Kirill Tkhai wrote:
> @@ -1945,6 +1942,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
> count_memcg_events(lruvec_memcg(lruvec), PGSTEAL_DIRECT,
> nr_reclaimed);
> }
> + reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
> + reclaim_stat->recent_rotated[1] = stat.nr_activate[1];

Surely this should be +=, right?

Otherwise we maintain essentially no history of page rotations and
that wreaks havoc on the page cache vs. swapping reclaim balance.

2019-05-28 16:09:20

by Kirill Tkhai

[permalink] [raw]
Subject: Re: [PATCH REBASED 1/4] mm: Move recent_rotated pages calculation to shrink_inactive_list()

On 28.05.2019 18:51, Johannes Weiner wrote:
> On Mon, Mar 18, 2019 at 12:27:59PM +0300, Kirill Tkhai wrote:
>> @@ -1945,6 +1942,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
>> count_memcg_events(lruvec_memcg(lruvec), PGSTEAL_DIRECT,
>> nr_reclaimed);
>> }
>> + reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
>> + reclaim_stat->recent_rotated[1] = stat.nr_activate[1];
>
> Surely this should be +=, right?
>
> Otherwise we maintain essentially no history of page rotations and
> that wreaks havoc on the page cache vs. swapping reclaim balance.

Sure, thanks.

Kirill