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=-5.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 6AB4DC3A5A1 for ; Wed, 21 Aug 2019 07:47:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C546233FE for ; Wed, 21 Aug 2019 07:47:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C546233FE 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 B34B86B02A3; Wed, 21 Aug 2019 03:47:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AE5476B02A4; Wed, 21 Aug 2019 03:47:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9D3BB6B02A5; Wed, 21 Aug 2019 03:47:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0235.hostedemail.com [216.40.44.235]) by kanga.kvack.org (Postfix) with ESMTP id 752C36B02A3 for ; Wed, 21 Aug 2019 03:47:26 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 26CDB2C0C for ; Wed, 21 Aug 2019 07:47:26 +0000 (UTC) X-FDA: 75845654892.26.cub15_5dfb79d86532e X-HE-Tag: cub15_5dfb79d86532e X-Filterd-Recvd-Size: 3654 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Wed, 21 Aug 2019 07:47:25 +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 A4FBCB027; Wed, 21 Aug 2019 07:47:23 +0000 (UTC) Date: Wed, 21 Aug 2019 09:47:21 +0200 From: Michal Hocko To: David Rientjes Cc: Edward Chron , Andrew Morton , Roman Gushchin , Johannes Weiner , Tetsuo Handa , Shakeel Butt , linux-mm@kvack.org, linux-kernel@vger.kernel.org, colona@arista.com Subject: Re: [PATCH] mm/oom: Add oom_score_adj value to oom Killed process message Message-ID: <20190821074721.GY3111@dhcp22.suse.cz> References: <20190821001445.32114-1-echron@arista.com> <20190821064732.GW3111@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed 21-08-19 00:19:37, David Rientjes wrote: > On Wed, 21 Aug 2019, Michal Hocko wrote: > > > > vm.oom_dump_tasks is pretty useful, however, so it's curious why you > > > haven't left it enabled :/ > > > > Because it generates a lot of output potentially. Think of a workload > > with too many tasks which is not uncommon. > > Probably better to always print all the info for the victim so we don't > need to duplicate everything between dump_tasks() and dump_oom_summary(). I believe that the motivation was to have a one line summary that is already parsed by log consumers. And that is in __oom_kill_process one. Also I do not think this patch improves things much for two reasons at leasts a) it doesn't really give you the whole list of killed tasks (this might be the whole memcg) and b) we already do have most important information in __oom_kill_process. If something is missing there I do not see a strong reason we cannot add it there. Like in this case. > Edward, how about this? > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -420,11 +420,17 @@ static int dump_task(struct task_struct *p, void *arg) > * State information includes task's pid, uid, tgid, vm size, rss, > * pgtables_bytes, swapents, oom_score_adj value, and name. > */ > -static void dump_tasks(struct oom_control *oc) > +static void dump_tasks(struct oom_control *oc, struct task_struct *victim) > { > pr_info("Tasks state (memory values in pages):\n"); > pr_info("[ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name\n"); > > + /* If vm.oom_dump_tasks is disabled, only show the victim */ > + if (!sysctl_oom_dump_tasks) { > + dump_task(victim, oc); > + return; > + } > + > if (is_memcg_oom(oc)) > mem_cgroup_scan_tasks(oc->memcg, dump_task, oc); > else { > @@ -465,8 +471,8 @@ static void dump_header(struct oom_control *oc, struct task_struct *p) > if (is_dump_unreclaim_slabs()) > dump_unreclaimable_slab(); > } > - if (sysctl_oom_dump_tasks) > - dump_tasks(oc); > + if (p || sysctl_oom_dump_tasks) > + dump_tasks(oc, p); > if (p) > dump_oom_summary(oc, p); > } -- Michal Hocko SUSE Labs