From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com [209.85.212.174]) by kanga.kvack.org (Postfix) with ESMTP id 6A0F76B006E for ; Tue, 21 Oct 2014 03:27:36 -0400 (EDT) Received: by mail-wi0-f174.google.com with SMTP id r20so1223302wiv.7 for ; Tue, 21 Oct 2014 00:27:35 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l2si11116796wix.39.2014.10.21.00.27.34 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 21 Oct 2014 00:27:34 -0700 (PDT) From: Michal Hocko Subject: [PATCH 1/4] freezer: Do not freeze tasks killed by OOM killer Date: Tue, 21 Oct 2014 09:27:12 +0200 Message-Id: <1413876435-11720-2-git-send-email-mhocko@suse.cz> In-Reply-To: <1413876435-11720-1-git-send-email-mhocko@suse.cz> References: <1413876435-11720-1-git-send-email-mhocko@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , "\\\"Rafael J. Wysocki\\\"" Cc: Cong Wang , David Rientjes , Tejun Heo , Oleg Nesterov , LKML , linux-mm@kvack.org, Linux PM list From: Cong Wang Since f660daac474c6f (oom: thaw threads if oom killed thread is frozen before deferring) OOM killer relies on being able to thaw a frozen task to handle OOM situation but a3201227f803 (freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE) has reorganized the code and stopped clearing freeze flag in __thaw_task. This means that the target task only wakes up and goes into the fridge again because the freezing condition hasn't changed for it. This reintroduces the bug fixed by f660daac474c6f. Fix the issue by checking for TIF_MEMDIE thread flag in freezing_slow_path and exclude the task from freezing completely. If a task was already frozen it would get woken by __thaw_task from OOM killer and get out of freezer after rechecking freezing(). Changes since v1 - put TIF_MEMDIE check into freezing_slowpath rather than in __refrigerator as per Oleg - return __thaw_task into oom_scan_process_thread because oom_kill_process will not wake task in the fridge because it is sleeping uninterruptible [mhocko@suse.cz: rewrote the changelog] Fixes: a3201227f803 (freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE) Cc: stable@vger.kernel.org # 3.3+ Cc: David Rientjes Cc: Michal Hocko Cc: "Rafael J. Wysocki" Cc: Tejun Heo Cc: Andrew Morton Signed-off-by: Cong Wang Signed-off-by: Michal Hocko Acked-by: Oleg Nesterov --- kernel/freezer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/freezer.c b/kernel/freezer.c index aa6a8aadb911..8f9279b9c6d7 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -42,6 +42,9 @@ bool freezing_slow_path(struct task_struct *p) if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK)) return false; + if (test_thread_flag(TIF_MEMDIE)) + return false; + if (pm_nosig_freezing || cgroup_freezing(p)) return true; -- 2.1.1 -- 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