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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 00FBEC282CD for ; Mon, 28 Jan 2019 18:43:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B72A42171F for ; Mon, 28 Jan 2019 18:43:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548701011; bh=hJrYZDLe+YFEGj7aoyevHKsgNVfjWv6antMiu3zBQUQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Jo3v3CrULKKNF80Jb4JMqSoR8AhChNX8rpMC08NsHptwIz2OB/ET1cLBZoHFeH3qG 5XiyDHXI7I7KI5YuMn/zSmpY1BDbUt8qprpon4FDsUhs7EuvmXq0fABSBStauSu+Ll +0jXZPWKnRgYnOtyjWOfxmjwZdsSYmHfXB9biZ/c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727878AbfA1Sna (ORCPT ); Mon, 28 Jan 2019 13:43:30 -0500 Received: from mx2.suse.de ([195.135.220.15]:56232 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727246AbfA1Sn3 (ORCPT ); Mon, 28 Jan 2019 13:43:29 -0500 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 E8810B018; Mon, 28 Jan 2019 18:43:27 +0000 (UTC) Date: Mon, 28 Jan 2019 19:43:26 +0100 From: Michal Hocko To: Andrew Morton Cc: Johannes Weiner , mm-commits@vger.kernel.org, penguin-kernel@i-love.sakura.ne.jp, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: + memcg-do-not-report-racy-no-eligible-oom-tasks.patch added to -mm tree Message-ID: <20190128184326.GT18811@dhcp22.suse.cz> References: <20190109190306.rATpT%akpm@linux-foundation.org> <20190125165624.GA17719@cmpxchg.org> <20190125172416.GB20411@dhcp22.suse.cz> <20190128102616.d7d63f8e1ecdf176bc313f8a@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190128102616.d7d63f8e1ecdf176bc313f8a@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 28-01-19 10:26:16, Andrew Morton wrote: > On Fri, 25 Jan 2019 18:24:16 +0100 Michal Hocko wrote: > > > > > out_of_memory > > > > select_bad_process # no task > > > > > > > > If Thread1 didn't race it would bail out from try_charge and force the > > > > charge. We can achieve the same by checking tsk_is_oom_victim inside the > > > > oom_lock and therefore close the race. > > > > > > > > [1] http://lkml.kernel.org/r/bb2074c0-34fe-8c2c-1c7d-db71338f1e7f@i-love.sakura.ne.jp > > > > Link: http://lkml.kernel.org/r/20190107143802.16847-3-mhocko@kernel.org > > > > Signed-off-by: Michal Hocko > > > > Cc: Tetsuo Handa > > > > Cc: Johannes Weiner > > > > Signed-off-by: Andrew Morton > > > > > > It looks like this problem is happening in production systems: > > > > > > https://www.spinics.net/lists/cgroups/msg21268.html > > > > > > where the threads don't exit because they are trapped writing out the > > > oom messages to a slow console (running the reproducer from this email > > > thread triggers the oom flooding). > > > > > > So IMO we should put this into 5.0 and add: > > > > Please note that Tetsuo has found out that this will not work with the > > CLONE_VM without CLONE_SIGHAND cases and his http://lkml.kernel.org/r/01370f70-e1f6-ebe4-b95e-0df21a0bc15e@i-love.sakura.ne.jp > > should handle this case as well. I've only had objections to the > > changelog but other than that the patch looked sensible to me. > > So I think you're saying that > > mm-oom-marks-all-killed-tasks-as-oom-victims.patch > and > memcg-do-not-report-racy-no-eligible-oom-tasks.patch > > should be dropped and that "[PATCH v2] memcg: killed threads should not > invoke memcg OOM killer" should be redone with some changelog > alterations and should be merged instead? Yup. -- Michal Hocko SUSE Labs