mm: vmstat: add isolate pages

If the system is running a heavy load of processes then concurrent reclaim
can isolate a large number of pages from the LRU. /proc/vmstat and the
output generated for an OOM do not show how many pages were isolated.

This has been observed during process fork bomb testing (mstctl11 in LTP).

This patch shows the information about isolated pages.

Reproduced via:

-----------------------
% ./hackbench 140 process 1000
   => OOM occur

active_anon:146 inactive_anon:0 isolated_anon:49245
 active_file:79 inactive_file:18 isolated_file:113
 unevictable:0 dirty:0 writeback:0 unstable:0 buffer:39
 free:370 slab_reclaimable:309 slab_unreclaimable:5492
 mapped:53 shmem:15 pagetables:28140 bounce:0

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.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/include/linux/mmzone.h b/include/linux/mmzone.h
index b3583b93b77e..9c50309b30a1 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -100,6 +100,8 @@ enum zone_stat_item {
         NR_BOUNCE,
         NR_VMSCAN_WRITE,
         NR_WRITEBACK_TEMP,      /* Writeback using temporary buffers */
+        NR_ISOLATED_ANON,       /* Temporary isolated pages from anon lru */
+        NR_ISOLATED_FILE,       /* Temporary isolated pages from file lru */
         NR_SHMEM,               /* shmem pages (included tmpfs/GEM pages) */
 #ifdef CONFIG_NUMA
         NUMA_HIT,               /* allocated in intended node */