[40/55] oom: use pte pages in OOM score

[Greg KH]

2.6.38-stable review patch.  If anyone has any objections, please let us know.

------------------

From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 mm/oom_kill.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -172,10 +172,13 @@ unsigned int oom_badness(struct task_str
 
 	/*
 	 * 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);
 
 	/*


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