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=-18.2 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,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 98E98C64E75 for ; Fri, 27 Nov 2020 09:55:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DB8821D91 for ; Fri, 27 Nov 2020 09:55:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="sfYOdVjR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726202AbgK0JzA (ORCPT ); Fri, 27 Nov 2020 04:55:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725865AbgK0Jy7 (ORCPT ); Fri, 27 Nov 2020 04:54:59 -0500 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 074E6C0613D4 for ; Fri, 27 Nov 2020 01:54:57 -0800 (PST) Received: by mail-wr1-x441.google.com with SMTP id 64so4893448wra.11 for ; Fri, 27 Nov 2020 01:54:57 -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=JjE5v+XtmXi4bhjUhwczYi8qu3IElsPJc6z70wBzRWs=; b=sfYOdVjRyzcbYRH/Ekm8wSub6oWEzdjbW2nDTAMnh+6ng+DbEs+mHTZUhXoUXiM0G/ 6hwWE5ZB2yeEMyCagbn48ngqnVd/Y5klQdMiAfN4mVSz+nY3HGFLtKuBtYX2clhCpvIG IuMvX40k0Uea4kH/0bOWOe35Y2bAVJs9VJ3/XgrZZsEVzh5EmsUsIr9iBr1J9hIIpQDR VvDvVN51IOVbbbe2X/suG6Ry3Slx41rPnME1ldpGZ+vwcCoSp4U8fYOSjwtj9jIHVz9v QCd6icNy7782CsjPEAlFmgSBNUV3YZN26AsSirMGaHi1jQF+cbbTSiArlLUnRo9sY/Z5 tARA== 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=JjE5v+XtmXi4bhjUhwczYi8qu3IElsPJc6z70wBzRWs=; b=ES1stdNdG3DrY5IUcLCGyTJFzEDiFYUeqMbkxXKZ0oi6rqRgqxfXX4ph6aVpSLgGip ug0Ev6K21VeQEv2pe49RpNXt9QhgN+CPmGrlnZk5V9URl7ECZWy2XsaG7IvXICB45Nm1 tvfnJb4IVtsDXjgaAVQNU6IpN+dLHkaKQacMBTDvPFuQX63wp1TbbzZC2fjtybjnNWG5 MmdDy2+vTaKPZrXpfWXUahy86tGl56aSemzH4c3KNT5A1nENjPyEx7piJ0p7+Udyb7vm OHoTLBioUx2ZSkEEFcVoqmABUpuRAfn2uWPdonIKDhrYBl06lJkgag5XjvbPHbrncboA 6whQ== X-Gm-Message-State: AOAM531KNqzw/wVcNl3n9WJcmOC3jPNCQPmshMqoEPBZ7zQcFU0ZMirK N/eCgVbe2MCTgHUv36ZqphSHug== X-Google-Smtp-Source: ABdhPJy8MKyha3Xk7UYSRiRLy3TVGJobBhb4KefTjlDXAMCo/TeSUVelqvExxjIfnbZXHjD1GJxklw== X-Received: by 2002:adf:dd52:: with SMTP id u18mr9079635wrm.44.1606470896481; Fri, 27 Nov 2020 01:54:56 -0800 (PST) Received: from google.com ([2a00:79e0:d:210:f693:9fff:fef4:a7ef]) by smtp.gmail.com with ESMTPSA id j127sm14205428wma.31.2020.11.27.01.54.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Nov 2020 01:54:56 -0800 (PST) Date: Fri, 27 Nov 2020 09:54:52 +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 v4 11/14] sched: Reject CPU affinity changes based on arch_task_cpu_possible_mask() Message-ID: <20201127095452.GB906877@google.com> References: <20201124155039.13804-1-will@kernel.org> <20201124155039.13804-12-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201124155039.13804-12-will@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Tuesday 24 Nov 2020 at 15:50:36 (+0000), Will Deacon wrote: > Reject explicit requests to change the affinity mask of a task via > set_cpus_allowed_ptr() if the requested mask is not a subset of the > mask returned by arch_task_cpu_possible_mask(). This ensures that the > 'cpus_mask' for a given task cannot contain CPUs which are incapable of > executing it, except in cases where the affinity is forced. I guess mentioning here (or as a comment) the 'funny' behaviour we get with cpusets wouldn't hurt. But this is a sensible patch nonetheless so: Reviewed-by: Quentin Perret Thanks, Quentin