From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f169.google.com (mail-pf0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id 25CC6828E2 for ; Wed, 17 Feb 2016 05:30:54 -0500 (EST) Received: by mail-pf0-f169.google.com with SMTP id q63so9369216pfb.0 for ; Wed, 17 Feb 2016 02:30:54 -0800 (PST) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id lq6si1065659pab.140.2016.02.17.02.30.52 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 17 Feb 2016 02:30:52 -0800 (PST) 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> Date: Wed, 17 Feb 2016 19:30:41 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: 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 >>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 -- 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