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, 11 insertions, 0 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 37143b924484..b535a2c1656c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -67,6 +67,8 @@ int putback_lru_pages(struct list_head *l)
 
         list_for_each_entry_safe(page, page2, l, lru) {
                 list_del(&page->lru);
+                dec_zone_page_state(page, NR_ISOLATED_ANON +
+                                    !!page_is_file_cache(page));
                 putback_lru_page(page);
                 count++;
         }
@@ -698,6 +700,8 @@ unlock:
                  * restored.
                  */
                 list_del(&page->lru);
+                dec_zone_page_state(page, NR_ISOLATED_ANON +
+                                    !!page_is_file_cache(page));
                 putback_lru_page(page);
         }
 
@@ -742,6 +746,13 @@ int migrate_pages(struct list_head *from,
         struct page *page2;
         int swapwrite = current->flags & PF_SWAPWRITE;
         int rc;
+        unsigned long flags;
+
+        local_irq_save(flags);
+        list_for_each_entry(page, from, lru)
+                __inc_zone_page_state(page, NR_ISOLATED_ANON +
+                                      !!page_is_file_cache(page));
+        local_irq_restore(flags);
 
         if (!swapwrite)
                 current->flags |= PF_SWAPWRITE;