mm: oom analysis: add shmem vmstat
Recently we encountered OOM problems due to memory use of the GEM cache.
Generally a large amuont of Shmem/Tmpfs pages tend to create a memory
shortage problem.
We often use the following calculation to determine the amount of shmem
pages:
shmem = NR_ACTIVE_ANON + NR_INACTIVE_ANON - NR_ANON_PAGES
however the expression does not consider isolated and mlocked pages.
This patch adds explicit accounting for pages used by shmem and tmpfs.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index dd51c68e..bcc7372 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -119,6 +119,8 @@
page->mapping = NULL;
mapping->nrpages--;
__dec_zone_page_state(page, NR_FILE_PAGES);
+ if (PageSwapBacked(page))
+ __dec_zone_page_state(page, NR_SHMEM);
BUG_ON(page_mapped(page));
/*
@@ -431,6 +433,8 @@
if (likely(!error)) {
mapping->nrpages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
+ if (PageSwapBacked(page))
+ __inc_zone_page_state(page, NR_SHMEM);
spin_unlock_irq(&mapping->tree_lock);
} else {
page->mapping = NULL;
diff --git a/mm/migrate.c b/mm/migrate.c
index 0edeac9..37143b9 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -312,7 +312,10 @@
*/
__dec_zone_page_state(page, NR_FILE_PAGES);
__inc_zone_page_state(newpage, NR_FILE_PAGES);
-
+ if (PageSwapBacked(page)) {
+ __dec_zone_page_state(page, NR_SHMEM);
+ __inc_zone_page_state(newpage, NR_SHMEM);
+ }
spin_unlock_irq(&mapping->tree_lock);
return 0;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e050f3..e50c225 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2139,7 +2139,7 @@
" unevictable:%lu"
" dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
- " mapped:%lu pagetables:%lu bounce:%lu\n",
+ " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
global_page_state(NR_ACTIVE_ANON),
global_page_state(NR_ACTIVE_FILE),
global_page_state(NR_INACTIVE_ANON),
@@ -2153,6 +2153,7 @@
global_page_state(NR_SLAB_RECLAIMABLE),
global_page_state(NR_SLAB_UNRECLAIMABLE),
global_page_state(NR_FILE_MAPPED),
+ global_page_state(NR_SHMEM),
global_page_state(NR_PAGETABLE),
global_page_state(NR_BOUNCE));
@@ -2175,6 +2176,7 @@
" dirty:%lukB"
" writeback:%lukB"
" mapped:%lukB"
+ " shmem:%lukB"
" slab_reclaimable:%lukB"
" slab_unreclaimable:%lukB"
" kernel_stack:%lukB"
@@ -2200,6 +2202,7 @@
K(zone_page_state(zone, NR_FILE_DIRTY)),
K(zone_page_state(zone, NR_WRITEBACK)),
K(zone_page_state(zone, NR_FILE_MAPPED)),
+ K(zone_page_state(zone, NR_SHMEM)),
K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
zone_page_state(zone, NR_KERNEL_STACK) *
diff --git a/mm/vmstat.c b/mm/vmstat.c
index ceda39b..7214a45 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -644,7 +644,7 @@
"nr_bounce",
"nr_vmscan_write",
"nr_writeback_temp",
-
+ "nr_shmem",
#ifdef CONFIG_NUMA
"numa_hit",
"numa_miss",