From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + oom-avoid-killing-a-task-if-a-thread-sharing-its-mm-cannot-be-killed.patch added to -mm tree Date: Mon, 23 Aug 2010 16:16:31 -0700 Message-ID: <201008232316.o7NNGVvA020394@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:37434 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752092Ab0HWXQr (ORCPT ); Mon, 23 Aug 2010 19:16:47 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: rientjes@google.com, kamezawa.hiroyu@jp.fujitsu.com, kosaki.motohiro@jp.fujitsu.com, riel@redhat.com, yinghan@google.com The patch titled oom: avoid killing a task if a thread sharing its mm cannot be killed has been added to the -mm tree. Its filename is oom-avoid-killing-a-task-if-a-thread-sharing-its-mm-cannot-be-killed.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: oom: avoid killing a task if a thread sharing its mm cannot be killed From: David Rientjes The oom killer's goal is to kill a memory-hogging task so that it may exit, free its memory, and allow the current context to allocate the memory that triggered it in the first place. Thus, killing a task is pointless if other threads sharing its mm cannot be killed because of its /proc/pid/oom_adj or /proc/pid/oom_score_adj value. This patch checks whether any other thread sharing p->mm has an oom_score_adj of OOM_SCORE_ADJ_MIN. If so, the thread cannot be killed and oom_badness(p) returns 0, meaning it's unkillable. Signed-off-by: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Rik van Riel Cc: Ying Han Signed-off-by: Andrew Morton --- mm/oom_kill.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff -puN mm/oom_kill.c~oom-avoid-killing-a-task-if-a-thread-sharing-its-mm-cannot-be-killed mm/oom_kill.c --- a/mm/oom_kill.c~oom-avoid-killing-a-task-if-a-thread-sharing-its-mm-cannot-be-killed +++ a/mm/oom_kill.c @@ -162,10 +162,11 @@ unsigned int oom_badness(struct task_str return 0; /* - * Shortcut check for OOM_SCORE_ADJ_MIN so the entire heuristic doesn't - * need to be executed for something that cannot be killed. + * Shortcut check for a thread sharing p->mm that is OOM_SCORE_ADJ_MIN + * so the entire heuristic doesn't need to be executed for something + * that cannot be killed. */ - if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { + if (atomic_read(&p->mm->oom_disable_count)) { task_unlock(p); return 0; } @@ -675,7 +676,7 @@ void out_of_memory(struct zonelist *zone read_lock(&tasklist_lock); if (sysctl_oom_kill_allocating_task && !oom_unkillable_task(current, NULL, nodemask) && - (current->signal->oom_adj != OOM_DISABLE)) { + current->mm && !atomic_read(¤t->mm->oom_disable_count)) { /* * oom_kill_process() needs tasklist_lock held. If it returns * non-zero, current could not be killed so we must fallback to _ Patches currently in -mm which might be from rientjes@google.com are fs-bio-integrityc-remove-dependency-on-__gfp_nofail.patch fs-bio-integrityc-return-enomem-on-kmalloc-failure.patch oom-add-per-mm-oom-disable-count.patch oom-avoid-killing-a-task-if-a-thread-sharing-its-mm-cannot-be-killed.patch oom-kill-all-threads-sharing-oom-killed-tasks-mm.patch jbd-remove-dependency-on-__gfp_nofail.patch