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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 94D7EC433DF for ; Tue, 13 Oct 2020 11:56:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 06A9D2080A for ; Tue, 13 Oct 2020 11:56:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=suse.com header.i=@suse.com header.b="VNQ2UQSq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 06A9D2080A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65490940009; Tue, 13 Oct 2020 07:56:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 605C1900002; Tue, 13 Oct 2020 07:56:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4CD4C940009; Tue, 13 Oct 2020 07:56:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0136.hostedemail.com [216.40.44.136]) by kanga.kvack.org (Postfix) with ESMTP id 1FD69900002 for ; Tue, 13 Oct 2020 07:56:46 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AD7C88249980 for ; Tue, 13 Oct 2020 11:56:45 +0000 (UTC) X-FDA: 77366750370.11.desk40_58097f527203 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id 876A7180F8B82 for ; Tue, 13 Oct 2020 11:56:45 +0000 (UTC) X-HE-Tag: desk40_58097f527203 X-Filterd-Recvd-Size: 3200 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Tue, 13 Oct 2020 11:56:45 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1602590204; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NK1kxW76+4fIJOasxtA/iRw1JAG8nedFaKNCzwTxxlw=; b=VNQ2UQSqnhkbSl2laJO3W0cMzOLzZvq96wtu9M1kZDXA/EeU9Ry+sq4YZg1NMI+dzSkgk1 y3r5pWXH5Kz46IICsP4/2OcgWg7pIdS4XVrHjgNo22U6sME/XG6SvY1myd+SLJR1btOvcs tdWoIlE+Hzji2TMcHmct5r0LCE5WD/Q= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E71E6AD63; Tue, 13 Oct 2020 11:56:43 +0000 (UTC) Date: Tue, 13 Oct 2020 13:56:43 +0200 From: Michal Hocko To: Ricardo =?iso-8859-1?Q?Ca=F1uelo?= Cc: akpm@linux-foundation.org, kernel@collabora.com, hch@lst.de, guro@fb.com, rientjes@google.com, mcgrof@kernel.org, keescook@chromium.org, yzaikin@google.com, linux-mm@kvack.org, sergey.senozhatsky@gmail.com, pmladek@suse.com, rostedt@goodmis.org Subject: Re: [PATCH] mm, oom: enable rate-limiting controls for oom dumps Message-ID: <20201013115643.GM29725@dhcp22.suse.cz> References: <20201009093014.9412-1-ricardo.canuelo@collabora.com> <20201012151804.GG29725@dhcp22.suse.cz> <20201013092339.225lb62rs7jwfzd6@rcn-XPS-13-9360> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20201013092339.225lb62rs7jwfzd6@rcn-XPS-13-9360> Content-Transfer-Encoding: quoted-printable 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 Tue 13-10-20 11:23:39, Ricardo Ca=F1uelo wrote: > Hi Michal, >=20 > Thanks for reviewing the patch and for your suggestions: >=20 > On lun 12-10-2020 17:18:04, Michal Hocko wrote: > > How does controling burst and interval solve the problem? Btw. this > > should be a part of the changelog which should explain not only what = but > > also why the change is needed. > >=20 > > It is true that the oom report can generate a lot of output. This is > > something that is brought up for quite some time. The largest part of > > the output tends to be the list of tasks and this seems to be the cas= e > > for you as well. Is the list of tasks so important that you need to h= ave > > it in the log? If not you can simply disable this part of the log > > altogether by /proc/sys/vm/oom_dump_tasks. >=20 > That could be another way to mitigate the problem, although losing some > information. I'll try to come up with a better alternative. Yes, but there is no way around this without losing information. You are either losing whole reports or a very noisy part of a report. I consider the first option to be worse because eligible tasks list is useful only very seldom. Another aspect of the problem is effectivelly broken rate limiting because of the way how it is implemented. That is something worth looking into IMHO. --=20 Michal Hocko SUSE Labs