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/drivers/base/node.c b/drivers/base/node.c
index b560c17f6d4e..1fe5536d404f 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -85,6 +85,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev,
                        "Node %d FilePages:      %8lu kB\n"
                        "Node %d Mapped:         %8lu kB\n"
                        "Node %d AnonPages:      %8lu kB\n"
+                       "Node %d Shmem:          %8lu kB\n"
                        "Node %d KernelStack:    %8lu kB\n"
                        "Node %d PageTables:     %8lu kB\n"
                        "Node %d NFS_Unstable:   %8lu kB\n"
@@ -117,6 +118,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev,
                        nid, K(node_page_state(nid, NR_FILE_PAGES)),
                        nid, K(node_page_state(nid, NR_FILE_MAPPED)),
                        nid, K(node_page_state(nid, NR_ANON_PAGES)),
+                       nid, K(node_page_state(nid, NR_SHMEM)),
                        nid, node_page_state(nid, NR_KERNEL_STACK) *
                                 THREAD_SIZE / 1024,
                        nid, K(node_page_state(nid, NR_PAGETABLE)),