From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751885AbcF0MPf (ORCPT ); Mon, 27 Jun 2016 08:15:35 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35888 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751673AbcF0MPc (ORCPT ); Mon, 27 Jun 2016 08:15:32 -0400 From: Michal Hocko To: Andrew Morton Cc: David Rientjes , Miao Xie , "Rafael J. Wysocki" , , LKML , linux-pm@vger.kernel.org, Michal Hocko Subject: [PATCH 1/2] freezer, oom: check TIF_MEMDIE on the correct task Date: Mon, 27 Jun 2016 14:15:18 +0200 Message-Id: <1467029719-17602-2-git-send-email-mhocko@kernel.org> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1467029719-17602-1-git-send-email-mhocko@kernel.org> References: <1467029719-17602-1-git-send-email-mhocko@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michal Hocko freezing_slow_path is checking TIF_MEMDIE to skip OOM killed tasks. It is, however, checking the flag on the current task rather than the given one. This is really confusing because freezing() can be called also on !current tasks. It would end up working correctly for its main purpose because __refrigerator will be always called on the current task so the oom victim will never get frozen. But it could lead to surprising results when a task which is freezing a cgroup got oom killed because only part of the cgroup would get frozen. This is highly unlikely but worth fixing as the resulting code would be more clear anyway. Signed-off-by: Michal Hocko --- kernel/freezer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/freezer.c b/kernel/freezer.c index a8900a3bc27a..6f56a9e219fa 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -42,7 +42,7 @@ bool freezing_slow_path(struct task_struct *p) if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK)) return false; - if (test_thread_flag(TIF_MEMDIE)) + if (test_tsk_thread_flag(p, TIF_MEMDIE)) return false; if (pm_nosig_freezing || cgroup_freezing(p)) -- 2.8.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: [PATCH 1/2] freezer, oom: check TIF_MEMDIE on the correct task Date: Mon, 27 Jun 2016 14:15:18 +0200 Message-ID: <1467029719-17602-2-git-send-email-mhocko@kernel.org> References: <1467029719-17602-1-git-send-email-mhocko@kernel.org> Return-path: In-Reply-To: <1467029719-17602-1-git-send-email-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: David Rientjes , Miao Xie , "Rafael J. Wysocki" , linux-mm@kvack.org, LKML , linux-pm@vger.kernel.org, Michal Hocko List-Id: linux-pm@vger.kernel.org From: Michal Hocko freezing_slow_path is checking TIF_MEMDIE to skip OOM killed tasks. It is, however, checking the flag on the current task rather than the given one. This is really confusing because freezing() can be called also on !current tasks. It would end up working correctly for its main purpose because __refrigerator will be always called on the current task so the oom victim will never get frozen. But it could lead to surprising results when a task which is freezing a cgroup got oom killed because only part of the cgroup would get frozen. This is highly unlikely but worth fixing as the resulting code would be more clear anyway. Signed-off-by: Michal Hocko --- kernel/freezer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/freezer.c b/kernel/freezer.c index a8900a3bc27a..6f56a9e219fa 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -42,7 +42,7 @@ bool freezing_slow_path(struct task_struct *p) if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK)) return false; - if (test_thread_flag(TIF_MEMDIE)) + if (test_tsk_thread_flag(p, TIF_MEMDIE)) return false; if (pm_nosig_freezing || cgroup_freezing(p)) -- 2.8.1 -- 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