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 B884CC4338F for ; Tue, 3 Aug 2021 10:32:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F072E60F01 for ; Tue, 3 Aug 2021 10:32:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F072E60F01 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 78E486B0033; Tue, 3 Aug 2021 06:32:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 73DF06B0036; Tue, 3 Aug 2021 06:32:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 606CF8D0001; Tue, 3 Aug 2021 06:32:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0165.hostedemail.com [216.40.44.165]) by kanga.kvack.org (Postfix) with ESMTP id 448C46B0033 for ; Tue, 3 Aug 2021 06:32:32 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id E415420BE4 for ; Tue, 3 Aug 2021 10:32:31 +0000 (UTC) X-FDA: 78433405302.10.7629F66 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf30.hostedemail.com (Postfix) with ESMTP id 721D0E008BC4 for ; Tue, 3 Aug 2021 10:32:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627986750; 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=JSNklHRjJyGfEqTMR4Etb5OIvyZd9bECma8BF8xb2qnghnjRz+7Nl4sSey5VReIQB/ever DY9eyZpm9TwpXnROuemkAfpaj9ehff/d7FcYRX1hg7KcZH2KXGm08Iz16lGks3od+xsk/+ DENKfrfjn7YHXa2CJE4d+0olo0Lpzy4= 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-499-XUxyX7eBNhC-NBmRmQPmCA-1; Tue, 03 Aug 2021 06:32:27 -0400 X-MC-Unique: XUxyX7eBNhC-NBmRmQPmCA-1 Received: by mail-wm1-f72.google.com with SMTP id f25-20020a1c6a190000b029024fa863f6b0so779857wmc.1 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=P9hrnmQ26NjEoqT9dtx2XVUahkTC8Tju9ZoqtCgjKz7IFt+5R3Yif5egBzaERwCjeG YTd4JpMyo3U/PLcDNkMw+HaWH5mdkovVG1eXed6vARQPNQLepgHU65Nd/yls7YMMiqYG o61p6kRfuxgu8qKRkxJmXA/mvxcywLFvLUobq9JdPXwmzYHeCV4HLauN4z3768Mc45o1 92XbtXlnIsZGd845YKlYCIoW3M4eDk6jey9adBFd2ydMvCnOEUl7R1fhhNw1A4L15CgH JbaSdZgMybXwQ4HSkGhW1o74grqWGeAwic3nLgz8xe1TfuKUYdfKxM4KFq6V4H2F79cI 9BRQ== X-Gm-Message-State: AOAM532o06FPodjul/33FdEUJtEIXKs0Evc9IiOqNnYmhZAPp9ezGa/P vWs5+sIgQpvexk/jwbqTlMNzNzXyhmOCdETY9C44f2c4p5NREZphzWNHfKgM2hStAhyd9PEz4lD p2lhxLXME3A== X-Received: by 2002:a1c:4487:: with SMTP id r129mr3499639wma.62.1627986746024; Tue, 03 Aug 2021 03:32:26 -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 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=JSNklHRj; spf=none (imf30.hostedemail.com: domain of atomlin@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=atomlin@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 721D0E008BC4 X-Stat-Signature: 1kbru6qfknzy6wdm41rxrncqi9ugy4q9 X-HE-Tag: 1627986751-617057 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 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