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 AB045C7618D for ; Wed, 15 Mar 2023 16:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232101AbjCOQZJ (ORCPT ); Wed, 15 Mar 2023 12:25:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232082AbjCOQYw (ORCPT ); Wed, 15 Mar 2023 12:24:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF6F923857; Wed, 15 Mar 2023 09:24:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A9E4861DFC; Wed, 15 Mar 2023 16:24:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A1E6C433D2; Wed, 15 Mar 2023 16:24:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678897482; bh=rukzdJCI+tw+s5fqfJFihxS3X4oqBD7ma0Je+Y6QpCI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gvcMCkZvmy0xyYulnpAkGL249vbZumxIZ0gmXkUWaLHYTmhw1kp33kMRZlKUg5a76 X44pZeW2eTX0mHmn2iwhbcGHa12xNEnuJertqUlxQxRTC8LM1winp7ziDhrja4Xo4V tKq84JCNasxgBzolzfo0cw+o2kc3rrFV4e+DJCpcevbiwn+vVedPEWX23oaWXkZKRY HgX7o5nl4rEs19UhpWrPMaZ42A++sXm7JfDVxHr0gmBnc+Dr23ZzeZU3TK2ZueGYYq lS07EIHkniiwkywE8VmoBG75ISitCjmfwdKKNkXh+iBKyxRazFcaGViCpbdGGXm6qr gVeSv56EqsbrA== Date: Wed, 15 Mar 2023 16:24:36 +0000 From: Will Deacon To: Waiman Long Cc: Tejun Heo , Zefan Li , Johannes Weiner , Shuah Khan , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Peter Zijlstra Subject: Re: [PATCH 0/5] cgroup/cpuset: Miscellaneous updates Message-ID: <20230315162436.GA19015@willie-the-truck> References: <20230306200849.376804-1-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230306200849.376804-1-longman@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Waiman, On Mon, Mar 06, 2023 at 03:08:44PM -0500, Waiman Long wrote: > This patch series includes miscellaneous update to the cpuset and its > testing code. > > Patch 2 is actually a follow-up of commit 3fb906e7fabb ("cgroup/cpuset: > Don't filter offline CPUs in cpuset_cpus_allowed() for top cpuset tasks"). > > Patches 3-4 are for handling corner cases when dealing with > task_cpu_possible_mask(). Thanks for cc'ing me on these. I ran my arm64 asymmetric tests and, fwiw, I get the same results as vanilla -rc2, so that's good. One behaviour that persists (and which I thought might be addressed by this series) is the following. Imagine a 4-CPU system with CPUs 0-1 being 64-bit only. If I configure a parent cpuset with 'cpuset.cpus' of "0-2" and a child cpuset with 'cpuset.cpus' of "0-1", then attaching a 32-bit task to the child cpuset will result in an affinity mask of 4. If I then change 'cpuset.cpus' of the parent cpuset to "0-1,3", the affinity mask of the task remains at '4' whereas it might be nice to update it to '8', in-line with the new affinity mask of the parent cpuset. Anyway, I'm not complaining (this is certainly _not_ a regression), but I thought I'd highlight it in case you were aiming to address this with your changes. Cheers, Will