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=-2.5 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A44CBC00307 for ; Fri, 6 Sep 2019 11:02:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 81F7D206BB for ; Fri, 6 Sep 2019 11:02:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81F7D206BB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 00D606B0003; Fri, 6 Sep 2019 07:02:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EFF9F6B0006; Fri, 6 Sep 2019 07:02:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DEF2E6B0007; Fri, 6 Sep 2019 07:02:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0229.hostedemail.com [216.40.44.229]) by kanga.kvack.org (Postfix) with ESMTP id BD36C6B0003 for ; Fri, 6 Sep 2019 07:02:36 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 58D75824CA35 for ; Fri, 6 Sep 2019 11:02:36 +0000 (UTC) X-FDA: 75904207512.05.name58_6e01532ee3832 X-HE-Tag: name58_6e01532ee3832 X-Filterd-Recvd-Size: 2304 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Fri, 6 Sep 2019 11:02:35 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6B409AF2C; Fri, 6 Sep 2019 11:02:34 +0000 (UTC) Date: Fri, 6 Sep 2019 13:02:33 +0200 From: Michal Hocko To: Tetsuo Handa Cc: David Rientjes , linux-mm@kvack.org, Andrew Morton , LKML Subject: Re: [RFC PATCH] mm, oom: disable dump_tasks by default Message-ID: <20190906110233.GE14491@dhcp22.suse.cz> References: <20190903144512.9374-1-mhocko@kernel.org> <20190904054004.GA3838@dhcp22.suse.cz> <12bcade2-4190-5e5e-35c6-7a04485d74b9@i-love.sakura.ne.jp> <20190905140833.GB3838@dhcp22.suse.cz> <20ec856d-0f1e-8903-dbe0-bbc8b7a1847a@i-love.sakura.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20ec856d-0f1e-8903-dbe0-bbc8b7a1847a@i-love.sakura.ne.jp> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri 06-09-19 19:46:10, Tetsuo Handa wrote: > On 2019/09/05 23:08, Michal Hocko wrote: > > On Thu 05-09-19 22:39:47, Tetsuo Handa wrote: > > [...] > >> There is nothing that prevents users from enabling oom_dump_tasks by sysctl. > >> But that requires a solution for OOM stalling problem. > > > > You can hardly remove stalling if you are not reducing the amount of > > output or get it into a different context. Whether the later is > > reasonable is another question but you are essentially losing "at the > > OOM event state". > > > > I am not losing "at the OOM event state". Please find "struct oom_task_info" > (for now) embedded into "struct task_struct" which holds "at the OOM event state". > > And my patch moves "printk() from dump_tasks()" from OOM context to WQ context. Workers might be blocked for unbound amount of time and so this information might be printed late. -- Michal Hocko SUSE Labs