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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 8D105C4743E for ; Fri, 4 Jun 2021 17:11:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78F466141D for ; Fri, 4 Jun 2021 17:11:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230444AbhFDRNO (ORCPT ); Fri, 4 Jun 2021 13:13:14 -0400 Received: from foss.arm.com ([217.140.110.172]:43798 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230311AbhFDRNL (ORCPT ); Fri, 4 Jun 2021 13:13:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2DF6B1063; Fri, 4 Jun 2021 10:11:25 -0700 (PDT) Received: from e113632-lin (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 463F73F73D; Fri, 4 Jun 2021 10:11:22 -0700 (PDT) From: Valentin Schneider To: Will Deacon , linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , Dietmar Eggemann , Daniel Bristot de Oliveira , kernel-team@android.com, Li Zefan Subject: Re: [PATCH v8 07/19] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() In-Reply-To: <20210602164719.31777-8-will@kernel.org> References: <20210602164719.31777-1-will@kernel.org> <20210602164719.31777-8-will@kernel.org> Date: Fri, 04 Jun 2021 18:11:20 +0100 Message-ID: <875yyteerr.mognet@arm.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/06/21 17:47, Will Deacon wrote: > Asymmetric systems may not offer the same level of userspace ISA support > across all CPUs, meaning that some applications cannot be executed by > some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do > not feature support for 32-bit applications on both clusters. > > Modify guarantee_online_cpus() to take task_cpu_possible_mask() into > account when trying to find a suitable set of online CPUs for a given > task. This will avoid passing an invalid mask to set_cpus_allowed_ptr() > during ->attach() and will subsequently allow the cpuset hierarchy to be > taken into account when forcefully overriding the affinity mask for a > task which requires migration to a compatible CPU. > > Cc: Li Zefan > Cc: Tejun Heo > Cc: Johannes Weiner > Signed-off-by: Will Deacon Reviewed-by: Valentin Schneider