[natty/ti-omap4 CVE 1/1] oom: use pte pages in OOM score

[Andy Whitcroft]

From: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com>

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

(cherry picked from commit f755a042d82b51b54f3bdd0890e5ea56c0fb6807)
CVE-2011-2498
BugLink: http://bugs.launchpad.net/bugs/922374
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 mm/oom_kill.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index ea16f72..49ea0cc 100644
--- 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);
 
 	/*
-- 
1.7.8.3