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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 3506AC4338F for ; Tue, 3 Aug 2021 10:32:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1881860F01 for ; Tue, 3 Aug 2021 10:32:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235299AbhHCKcr (ORCPT ); Tue, 3 Aug 2021 06:32:47 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:57979 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235229AbhHCKcn (ORCPT ); Tue, 3 Aug 2021 06:32:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627986748; 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: in-reply-to:in-reply-to:references:references; bh=cbPTa2hEWdD7Y8ezaxCFaxMcbtkwVc60EGzp199OkUI=; b=IgwI4MQ+9twVZqvHjZPiEqeXmTNhftHHunW/pNyynSa61Gsm7BlYXiZbDU+FQYpuVEmOJ8 KSJe+yuvi1hfJwOYNAX3l45e1q30sAoW7BnhXZIDKRJC+UgbVkHgStTiOpQZK0fvjyDVuA 5hpn+PE6GjyFlGTMP0g3M6t5xidBX/I= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-472-n1Xrql6DOGS5C6KKCGc9CA-1; Tue, 03 Aug 2021 06:32:27 -0400 X-MC-Unique: n1Xrql6DOGS5C6KKCGc9CA-1 Received: by mail-wm1-f72.google.com with SMTP id d72-20020a1c1d4b0000b029025164ff3ebfso767793wmd.7 for ; Tue, 03 Aug 2021 03:32:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=cbPTa2hEWdD7Y8ezaxCFaxMcbtkwVc60EGzp199OkUI=; b=ApYph/4cXc2peO9lEfOUgLHkY0NalGsaIlZiOduv8gu9MpwJERWE5bhyS1j734StsM 9571Y/GriPr60zsMGXqYbQyEPkdz7ZhcvFqfGwqk5G/HaBg9CQAjlNi2HMhBr9mS5dWI FMgO4ppW3HJBgT81REmgCjnY0UmrADQiEQ9YIIqRLCYB/vNHE/I5o2efyxvLPh8KIKpL B7hCWK77upC2YZFSpxLK9AiVVD31hPfGLoB9NLBNKESV5LeNd0oNEn0we28sI6F27My5 lNz4zfbbwaHBy3m9I3ybfUEaItIHE3ZVMMSrIFZ0luRWrZqAJOjrWmU6N6kG+1f9QPRy oAeQ== X-Gm-Message-State: AOAM532D+dhr8OHxdaZWSD6MVOaQl0Hzsgi8bi/zR+8lkzOYfmP2jDs3 K7pl4vxxMRHDGB3iIVRFbwWMjqSwRbg5xcOgxaiOido3TGOEQHPMTHyoR7MBZTkwbEYHkYOUEhi bJv7TJ42L6nWdWG1Vq9WCZmY= X-Received: by 2002:a1c:4487:: with SMTP id r129mr3499611wma.62.1627986745758; Tue, 03 Aug 2021 03:32:25 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwiuH6Yxazd1Xa3OEWf5D3y4JCoKEmscKsCBIsfPdBqyBkrM8+JwgVbCHp81+RoANDH5/xcIQ== X-Received: by 2002:a1c:4487:: with SMTP id r129mr3499602wma.62.1627986745629; Tue, 03 Aug 2021 03:32:25 -0700 (PDT) Received: from localhost ([79.67.181.135]) by smtp.gmail.com with ESMTPSA id d15sm7442140wri.96.2021.08.03.03.32.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Aug 2021 03:32:25 -0700 (PDT) Date: Tue, 3 Aug 2021 11:32:22 +0100 From: Aaron Tomlin To: Michal Hocko Cc: linux-mm@kvack.org, akpm@linux-foundation.org, penguin-kernel@i-love.sakura.ne.jp, rientjes@google.com, llong@redhat.com, neelx@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mm/oom_kill: show oom eligibility when displaying the current memory state of all tasks Message-ID: <20210803103222.wethf6pj3rh2b2uq@ava.usersys.com> X-PGP-Key: http://pgp.mit.edu/pks/lookup?search=atomlin%40redhat.com X-PGP-Fingerprint: 7906 84EB FA8A 9638 8D1E 6E9B E2DE 9658 19CC 77D6 References: <20210730162002.279678-1-atomlin@redhat.com> <20210802151250.lqn5fu5pioygsry6@ava.usersys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2021-08-03 09:05 +0200, Michal Hocko wrote: > There were some attempts to print oom_score during OOM. E.g. > http://lkml.kernel.org/r/20190808183247.28206-1-echron@arista.com. That > one was rejected on the grounds that the number on its own doesn't > really present any real value. It is really only valuable when comparing > to other potential oom victims. I have to say I am still worried about > printing this internal scoring as it should have really been an > implementation detail but with /proc//oom_score this is likely a > lost battle and I am willing to give up on that front. Understood. > I am still not entirely convinced this is worth doing though. > oom_badness is not a cheap operation. task_lock has to be taken again > during dump_tasks for each task so the already quite expensive operation > will be more so. Is this really something we cannot live without? Fair enough and I now agree, it is unquestionably not worth it. Kind regards, -- Aaron Tomlin