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>

1 files changed, 4 insertions, 1 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e050f325ebd..e50c22545b8f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2139,7 +2139,7 @@ void show_free_areas(void)
                 " 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 @@ void show_free_areas(void)
                 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 @@ void show_free_areas(void)
                         " dirty:%lukB"
                         " writeback:%lukB"
                         " mapped:%lukB"
+                        " shmem:%lukB"
                         " slab_reclaimable:%lukB"
                         " slab_unreclaimable:%lukB"
                         " kernel_stack:%lukB"
@@ -2200,6 +2202,7 @@ void show_free_areas(void)
                         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) *