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authorDavid Rientjes <rientjes@google.com>2012-06-20 12:52:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-06-20 14:39:35 -0700
commit61eafb00d55dfbccdfce543c6b60e369ff4f8f18 (patch)
treee2be309a7412de35dd8414ea030b6650d2ea8b75 /mm/oom_kill.c
parentfbb24a3a915f105016f1c828476be11aceac8504 (diff)
downloadlinux-61eafb00d55dfbccdfce543c6b60e369ff4f8f18.tar.gz
mm, oom: fix and cleanup oom score calculations
The divide in p->signal->oom_score_adj * totalpages / 1000 within oom_badness() was causing an overflow of the signed long data type. This adds both the root bias and p->signal->oom_score_adj before doing the normalization which fixes the issue and also cleans up the calculation. Tested-by: Dave Jones <davej@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/oom_kill.c')
-rw-r--r--mm/oom_kill.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 416637f0e92..77775138e93 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -184,6 +184,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
const nodemask_t *nodemask, unsigned long totalpages)
{
long points;
+ long adj;
if (oom_unkillable_task(p, memcg, nodemask))
return 0;
@@ -192,7 +193,8 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
if (!p)
return 0;
- if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+ adj = p->signal->oom_score_adj;
+ if (adj == OOM_SCORE_ADJ_MIN) {
task_unlock(p);
return 0;
}
@@ -210,14 +212,11 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
* implementation used by LSMs.
*/
if (has_capability_noaudit(p, CAP_SYS_ADMIN))
- points -= 30 * totalpages / 1000;
+ adj -= 30;
- /*
- * /proc/pid/oom_score_adj ranges from -1000 to +1000 such that it may
- * either completely disable oom killing or always prefer a certain
- * task.
- */
- points += p->signal->oom_score_adj * totalpages / 1000;
+ /* Normalize to oom_score_adj units */
+ adj *= totalpages / 1000;
+ points += adj;
/*
* Never return 0 for an eligible task regardless of the root bonus and