From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0014AC4646D for ; Mon, 6 Aug 2018 10:47:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B1E1521A04 for ; Mon, 6 Aug 2018 10:47:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1E1521A04 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729884AbeHFMzd (ORCPT ); Mon, 6 Aug 2018 08:55:33 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:62723 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726678AbeHFMzc (ORCPT ); Mon, 6 Aug 2018 08:55:32 -0400 Received: from fsav105.sakura.ne.jp (fsav105.sakura.ne.jp [27.133.134.232]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id w76Al3q4084123; Mon, 6 Aug 2018 19:47:03 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav105.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav105.sakura.ne.jp); Mon, 06 Aug 2018 19:47:03 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav105.sakura.ne.jp) Received: from [192.168.1.8] (softbank126074194044.bbtec.net [126.74.194.44]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id w76Al2ZR084104 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 6 Aug 2018 19:47:03 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Subject: Re: WARNING in try_charge To: Dmitry Vyukov , Michal Hocko Cc: syzbot , cgroups@vger.kernel.org, Johannes Weiner , LKML , Linux-MM , syzkaller-bugs , Vladimir Davydov References: <0000000000005e979605729c1564@google.com> <20180806091552.GE19540@dhcp22.suse.cz> <20180806094827.GH19540@dhcp22.suse.cz> From: Tetsuo Handa Message-ID: <884de816-671a-44d4-a6a1-2ad7eff53715@I-love.SAKURA.ne.jp> Date: Mon, 6 Aug 2018 19:47:00 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/08/06 19:39, Dmitry Vyukov wrote: > On Mon, Aug 6, 2018 at 11:48 AM, Michal Hocko wrote: >> Btw. running with the above diff on top might help us to ideantify >> whether this is a pre-mature warning or a valid one. Still useful to >> find out. Since syzbot already found a syz reproducer, you can ask syzbot to test it. > > The bug report has a reproducer, so you can run it with the patch. Or > ask syzbot to test your patch: > https://github.com/google/syzkaller/blob/master/docs/syzbot.md#testing-patches > Which basically boils down to saying: > > #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > master Excuse me, but this is linux-next only problem. Therefore, #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4603ad75c9a9..852cd3dbdcd9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1388,6 +1388,8 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, bool ret; mutex_lock(&oom_lock); + pr_info("task=%s pid=%d invoked memcg oom killer. oom_victim=%d\n", + current->comm, current->pid, tsk_is_oom_victim(current)); ret = out_of_memory(&oc); mutex_unlock(&oom_lock); return ret; F.Y.I. Waiting until __mmput() completes (with timeout using OOM score feedback) ( https://syzkaller.appspot.com/x/patch.diff?x=101e449c400000 ) solves this race.