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=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 AF3A7C63798 for ; Thu, 19 Nov 2020 09:29:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5203F246E4 for ; Thu, 19 Nov 2020 09:29:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="W7Ip5bay" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726949AbgKSJ32 (ORCPT ); Thu, 19 Nov 2020 04:29:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726809AbgKSJ32 (ORCPT ); Thu, 19 Nov 2020 04:29:28 -0500 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA5BEC0613D4 for ; Thu, 19 Nov 2020 01:29:27 -0800 (PST) Received: by mail-wm1-x343.google.com with SMTP id h21so6078014wmb.2 for ; Thu, 19 Nov 2020 01:29:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=3JcU1zb6u51rjqw92Mq4g5Cn0LJ6Or+HL8YfF22EvLM=; b=W7Ip5bayzomghQnl06eSsIee8Qt9OFEXsbQgZAju7Tck5ryIp1znlAMWCoqtknPV8g 7W9QBI+GXm8CVeKN0dmt1LkNVrGZSzQPCobGQsnqsZ6dOVv+gwgD1a9VjF5ZFDCCtYwr /EYieeI32R/rOVJ4pEC98SoLb/+N3OSHIvxHTMy+Ktm0yU1G/nCsQF9gaVaoNbz/PVTA VVw/g9QzJaFDotVxD4nVL2q8aRMe8BmPhEqNd0khTLpEObgDnT+AMBKhSGOYSCuGTE1S 2DrWO4rBDWth99p4T/4QJrH5VDXlcuWC5NKtZqetOQLMQIeJ1+yk/V1bHfVxqIfaMBaI ijdw== 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=3JcU1zb6u51rjqw92Mq4g5Cn0LJ6Or+HL8YfF22EvLM=; b=RHEO3is7r1buma7WSXojtM2vW89SiJVab9tQT1yypxDBPDvEAasxv2LBAofA4NGcrJ wut/P5Ndgql8ycsanI6xtMKKkU8w9YEll9669WlWEOuoYWZWM+P9PkEzZQJi1jBbxaaR 2WPsef4zG62cDuW0L3iH2XM/TpZQ8H2x4mlL0dXI9JpZ9+75YbCdf8ntPedt1VieVL4x 1zIkKNqrCKp7f0kLg+wC+b8NxYr6v/8f+BGLydqTvLrT8AXiXjBKDIg6UEunLvn6+LiA oH9cXSCeEVLGxiTg59MSkOpcYYdnChcqZ2jpjhGZb6mEpY6DrVEPWLqGp2FM/jp+eUqz XAzA== X-Gm-Message-State: AOAM532u9M+A0kWo2PXU1+pUOOOG0bE1UDzLc90oOgRw0r0NRdZxyQG3 QysYKxrAUF0IhwOg3y7hiekNVw== X-Google-Smtp-Source: ABdhPJzZT2RkNoWhXvP6tMmxJ/IWICezm7c5mwJnpHvk8eoIY48sGpyqV3pAwPLpkUwa+COXNIsc0A== X-Received: by 2002:a1c:a5d8:: with SMTP id o207mr3536870wme.0.1605778166295; Thu, 19 Nov 2020 01:29:26 -0800 (PST) Received: from google.com ([2a00:79e0:d:210:f693:9fff:fef4:a7ef]) by smtp.gmail.com with ESMTPSA id j4sm37543361wrn.83.2020.11.19.01.29.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Nov 2020 01:29:25 -0800 (PST) Date: Thu, 19 Nov 2020 09:29:22 +0000 From: Quentin Perret To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Tejun Heo , Li Zefan , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , kernel-team@android.com Subject: Re: [PATCH v3 09/14] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Message-ID: <20201119092922.GC2416649@google.com> References: <20201113093720.21106-1-will@kernel.org> <20201113093720.21106-10-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201113093720.21106-10-will@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Friday 13 Nov 2020 at 09:37:14 (+0000), Will Deacon wrote: > If the scheduler cannot find an allowed CPU for a task, > cpuset_cpus_allowed_fallback() will widen the affinity to cpu_possible_mask > if cgroup v1 is in use. > > In preparation for allowing architectures to provide their own fallback > mask, just return early if we're not using cgroup v2 and allow > select_fallback_rq() to figure out the mask by itself. > > Cc: Li Zefan > Cc: Tejun Heo > Cc: Johannes Weiner > Signed-off-by: Will Deacon That makes select_fallback_rq() slightly more expensive if you're using cgroup v1, but I don't expect that be really measurable in real-world workloads, so: Reviewed-by: Quentin Perret Thanks, Quentin