From 1e11ad8dc42975d5c2bab7d478f6cd875602eda4 Mon Sep 17 00:00:00 2001
From: David Rientjes <rientjes@google.com>
Date: Fri, 8 Jun 2012 13:21:26 -0700
Subject: [PATCH] mm, oom: fix badness score underflow
If the privileges given to root threads (3% of allowable memory) or a
negative value of /proc/pid/oom_score_adj happen to exceed the amount of
rss of a thread, its badness score overflows as a result of commit
a7f638f999ff ("mm, oom: normalize oom scores to oom_score_adj scale only
for userspace").
Fix this by making the type signed and return 1, meaning the thread is
still eligible for kill, if the value is negative.
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/oom_kill.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index ed0e19677360fa..416637f0e92453 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -183,7 +183,7 @@ static bool oom_unkillable_task(struct task_struct *p,
unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
const nodemask_t *nodemask, unsigned long totalpages)
{
- unsigned long points;
+ long points;
if (oom_unkillable_task(p, memcg, nodemask))
return 0;
@@ -223,7 +223,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
* Never return 0 for an eligible task regardless of the root bonus and
* oom_score_adj (oom_score_adj can't be OOM_SCORE_ADJ_MIN here).
*/
- return points ? points : 1;
+ return points > 0 ? points : 1;
}
/*
--
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