oom: use pte pages in OOM score

commit f755a042d82b51b54f3bdd0890e5ea56c0fb6807 upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index ea16f720705eddf1f728b49098b70f0b0b2d9534..49ea0cc9ae1297f295602020c04a185b011c016a 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -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);
 
        /*