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, 2 insertions, 0 deletions

diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 1fc588f430e4..171e052c07b3 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -81,6 +81,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
                 "Writeback:      %8lu kB\n"
                 "AnonPages:      %8lu kB\n"
                 "Mapped:         %8lu kB\n"
+                "Shmem:          %8lu kB\n"
                 "Slab:           %8lu kB\n"
                 "SReclaimable:   %8lu kB\n"
                 "SUnreclaim:     %8lu kB\n"
@@ -125,6 +126,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
                 K(global_page_state(NR_WRITEBACK)),
                 K(global_page_state(NR_ANON_PAGES)),
                 K(global_page_state(NR_FILE_MAPPED)),
+                K(global_page_state(NR_SHMEM)),
                 K(global_page_state(NR_SLAB_RECLAIMABLE) +
                                 global_page_state(NR_SLAB_UNRECLAIMABLE)),
                 K(global_page_state(NR_SLAB_RECLAIMABLE)),