oom: use pte pages in OOM score
KOSAKI Motohiro [Wed, 27 Apr 2011 22:26:50 +0000 (15:26 -0700)]
PTE pages eat up memory just like anything else, but we do not account for
them in any way in the OOM scores.  They are also _guaranteed_ to get
freed up when a process is OOM killed, while RSS is not.

Reported-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org> [2.6.36+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/oom_kill.c

index 83fb72c..f52e85c 100644 (file)
@@ -172,10 +172,13 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
 
        /*
         * The baseline for the badness score is the proportion of RAM that each
-        * task's rss and swap space use.
+        * task's rss, pagetable and swap space use.
         */
-       points = (get_mm_rss(p->mm) + get_mm_counter(p->mm, MM_SWAPENTS)) * 1000 /
-                       totalpages;
+       points = get_mm_rss(p->mm) + p->mm->nr_ptes;
+       points += get_mm_counter(p->mm, MM_SWAPENTS);
+
+       points *= 1000;
+       points /= totalpages;
        task_unlock(p);
 
        /*