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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AB8DEB64DA for ; Mon, 10 Jul 2023 20:17:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230239AbjGJURO (ORCPT ); Mon, 10 Jul 2023 16:17:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229469AbjGJURM (ORCPT ); Mon, 10 Jul 2023 16:17:12 -0400 Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 752EBBB for ; Mon, 10 Jul 2023 13:17:11 -0700 (PDT) Received: by mail-pg1-x52a.google.com with SMTP id 41be03b00d2f7-55b1238cab4so2515211a12.2 for ; Mon, 10 Jul 2023 13:17:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1689020231; x=1691612231; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=pVlvV6OUzFpdMtXuozvrxmT75oR8hw0lyEeMlWOoDBE=; b=YjKHl2yw/GK0nJVEAE/eMY/hM27z9xu0QlQss3u1pSAoHubsOvJ8LzzCVywm+Q/faZ ty3RJjP+/kW6rG818cqw/wfbiHuRE3297aORL5fsTV2fBuY1oRIo+wHAtup5Yxutpkzc Yect8Gd9MSyNB2SIOylAO7fqN2vw3zmx9RU4xFWHBsIa0BvS/ZydW/LrgmZ1VuFWIACk 2hf9G2VuLqHHReCKzd/CgjoqCakKmurU68GOguRJY5BS5Jo7xDiQsMhU3ZEDfG7m0uxF ratJ5HQ+VgnKe5uI7vtDLTIUH1Iwp5XdhFFPwIMMRKnkJ/Lm65dQgTupy/pataK1ulgE rP4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689020231; x=1691612231; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=pVlvV6OUzFpdMtXuozvrxmT75oR8hw0lyEeMlWOoDBE=; b=GeI6EUTsjU3WgUq3dwQlFutgx7w5VAHRwaGAetN/YL+Oyttvizy+rWQ8J7hYSAw40v U0Iq12YgZdOcI57uhtEG7mvb17vlH++9gCZZHy1dxwsI+9YdJ+2DKi53o4OVV+2PMfoF cIvTkzLTEaN1wbpcqbjVwZlzCqvmnbFbVyZIidhEdMP0OYZSsHUSnfClyEYyESpzvHYF mWeZodAp1UjfizlS/JxYYOATieSLg+TKud/XhGJ5pBEbQNNUHTlAqXURHV92TEAFxORb keiIPSQROMjHOBQBTvQq1uzWKkg0Vm+TOqGm1fcia3viF4Muvb474AFZS1Y3pF0A0vpi iebw== X-Gm-Message-State: ABy/qLbF0aiyXj6d9HJVSSZDRsZnyQ2ci/v3E+72rCHurgyi37Zz4NH6 WQQDpC/NN34gL1dycP0fyqw= X-Google-Smtp-Source: APBJJlHaMNYOEh2NxYz1HiiDfOdtxRh+bLsh7818E2xlEY6wn0zCoH+H7UZemLZaqlpqmHKaaj65ng== X-Received: by 2002:a17:902:758b:b0:1b8:1b84:93e5 with SMTP id j11-20020a170902758b00b001b81b8493e5mr11462659pll.1.1689020230717; Mon, 10 Jul 2023 13:17:10 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:e2fe]) by smtp.gmail.com with ESMTPSA id x7-20020a1709027c0700b001b7e63cfa19sm277918pll.234.2023.07.10.13.17.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Jul 2023 13:17:10 -0700 (PDT) Sender: Tejun Heo Date: Mon, 10 Jul 2023 10:17:08 -1000 From: Tejun Heo To: Phil Auld Cc: linux-kernel@vger.kernel.org, Juri Lelli , Ingo Molnar , Daniel Bristot de Oliveira , Peter Zijlstra , Vincent Guittot , Dietmar Eggemann , Valentin Schneider , Ben Segall , Steven Rostedt , Mel Gorman , Frederic Weisbecker Subject: Re: [PATCH v5 1/2] sched, cgroup: Restore meaning to hierarchical_quota Message-ID: References: <20230707195748.2918490-1-pauld@redhat.com> <20230707195748.2918490-2-pauld@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230707195748.2918490-2-pauld@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Fri, Jul 07, 2023 at 03:57:47PM -0400, Phil Auld wrote: > @@ -11038,11 +11038,14 @@ static int tg_cfs_schedulable_down(struct task_group *tg, void *data) > > /* > * Ensure max(child_quota) <= parent_quota. On cgroup2, > - * always take the min. On cgroup1, only inherit when no > - * limit is set: > + * always take the non-RUNTIME_INF min. On cgroup1, only > + * inherit when no limit is set: > */ > if (cgroup_subsys_on_dfl(cpu_cgrp_subsys)) { > - quota = min(quota, parent_quota); > + if (quota == RUNTIME_INF) > + quota = parent_quota; > + else if (parent_quota != RUNTIME_INF) > + quota = min(quota, parent_quota); Can you please add a comment explaining how hierarchical_quota is used in cgroup2? It seems like you're using it to detect whether bw limit is enforced for a given cgroup, which is fine, but the above code in isolation looks a bit curious because it doesn't serve any purpose by itself. Thanks. -- tejun