From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx198.postini.com [74.125.245.198]) by kanga.kvack.org (Postfix) with SMTP id 4474B6B00DE for ; Mon, 11 Jun 2012 05:11:53 -0400 (EDT) Received: by pbbrp2 with SMTP id rp2so6466452pbb.14 for ; Mon, 11 Jun 2012 02:11:52 -0700 (PDT) Date: Mon, 11 Jun 2012 02:11:50 -0700 (PDT) From: David Rientjes Subject: [patch 3.5-rc2] mm, oom: fix and cleanup oom score calculations In-Reply-To: <20120611004602.GA29713@redhat.com> Message-ID: References: <20120604152710.GA1710@redhat.com> <20120605174454.GA23867@redhat.com> <20120608210330.GA21010@redhat.com> <4FD412CB.9060809@gmail.com> <20120610201055.GA27662@redhat.com> <20120611004602.GA29713@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Linus Torvalds Cc: Dave Jones , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org 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 Signed-off-by: David Rientjes --- mm/oom_kill.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c --- 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org