From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934197AbcBQKat (ORCPT ); Wed, 17 Feb 2016 05:30:49 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:13453 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933935AbcBQKaq (ORCPT ); Wed, 17 Feb 2016 05:30:46 -0500 To: mhocko@kernel.org, akpm@linux-foundation.org Cc: rientjes@google.com, mgorman@suse.de, oleg@redhat.com, torvalds@linux-foundation.org, hughd@google.com, andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/6] mm,oom: don't abort on exiting processes when selecting a victim. From: Tetsuo Handa References: <201602171928.GDE00540.SLJMOFFQOHtFVO@I-love.SAKURA.ne.jp> In-Reply-To: <201602171928.GDE00540.SLJMOFFQOHtFVO@I-love.SAKURA.ne.jp> Message-Id: <201602171930.AII18204.FMOSVFQFOJtLOH@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.51 PL2] X-Accept-Language: ja,en,zh Date: Wed, 17 Feb 2016 19:30:41 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From 22bd036766e70f0df38c38f3ecc226e857d20faf Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Wed, 17 Feb 2016 16:30:59 +0900 Subject: [PATCH 2/6] mm,oom: don't abort on exiting processes when selecting a victim. Currently, oom_scan_process_thread() returns OOM_SCAN_ABORT when there is a thread which is exiting. But it is possible that that thread is blocked at down_read(&mm->mmap_sem) in exit_mm() called from do_exit() whereas one of threads sharing that memory is doing a GFP_KERNEL allocation between down_write(&mm->mmap_sem) and up_write(&mm->mmap_sem) (e.g. mmap()). Under such situation, the OOM killer does not choose a victim, which results in silent OOM livelock problem. This patch changes oom_scan_process_thread() not to return OOM_SCAN_ABORT when there is a thread which is exiting. Signed-off-by: Tetsuo Handa --- mm/oom_kill.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 27949ef..a3868fd 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -311,9 +311,6 @@ enum oom_scan_t oom_scan_process_thread(struct oom_control *oc, if (oom_task_origin(task)) return OOM_SCAN_SELECT; - if (task_will_free_mem(task) && !is_sysrq_oom(oc)) - return OOM_SCAN_ABORT; - return OOM_SCAN_OK; } -- 1.8.3.1