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=-8.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 2A051C4320A for ; Wed, 18 Aug 2021 12:19:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06ABF6103A for ; Wed, 18 Aug 2021 12:19:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235869AbhHRMTr (ORCPT ); Wed, 18 Aug 2021 08:19:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:48292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233634AbhHRMTn (ORCPT ); Wed, 18 Aug 2021 08:19:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C9AA26103E; Wed, 18 Aug 2021 12:19:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629289149; bh=8ktxnAXgo0Y8fZiDQP9McWgd+yggDijrLt0O/GE7g4g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Smy5CjjU8ZEY0tW7BAvTw//U/uF7nuT8moUBCzWyP4fw7jgQUVwkiA7zQ40j2Anfc ubu+AY8gZL6Oa+GP2iE3JR8v0rtRpQT2Hp9Z4brwznzhUpMOi/WdWOt3XWraDTfb7/ FgfSVs4YYvIfnaqoucgUw/HLxyrGpaNQKHXS1pDQiOLQDWIAaENcmaDHS584Q1LiHN ShIjsMksXt4NCSlkQNMddKQoog+WABpmbSkew04Au4fg7P3+tFH7cr9viKwaXGpM5F ZeH467hUwi+gXgq6g8paJ0C90tZccOZx9Wgcynxfvqi07VIg0xnPKt4ETsogt637Te lVwFxPMMmgyyA== Date: Wed, 18 Aug 2021 13:19:01 +0100 From: Will Deacon To: Peter Zijlstra Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , 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 , Valentin Schneider , Mark Rutland , kernel-team@android.com Subject: Re: [PATCH v11 08/16] sched: Allow task CPU affinity to be restricted on asymmetric systems Message-ID: <20210818121900.GC14107@willie-the-truck> References: <20210730112443.23245-1-will@kernel.org> <20210730112443.23245-9-will@kernel.org> <20210818104227.GA13828@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 18, 2021 at 01:53:28PM +0200, Peter Zijlstra wrote: > On Wed, Aug 18, 2021 at 12:56:41PM +0200, Peter Zijlstra wrote: > > On Wed, Aug 18, 2021 at 11:42:28AM +0100, Will Deacon wrote: > > > > I think the idea looks good, but perhaps we could wrap things up a bit: > > > > > > /* Comment about why this is useful with RT */ > > > static cpumask_t *clear_user_cpus_ptr(struct task_struct *p) > > > { > > > struct cpumask *user_mask = NULL; > > > > > > swap(user_mask, p->user_cpus_ptr); > > > return user_mask; > > > } > > > > > > void release_user_cpus_ptr(struct task_struct *p) > > > { > > > kfree(clear_user_cpus_ptr(p)); > > > } > > > > > > Then just use clear_user_cpus_ptr() in sched/core.c where we know what > > > we're doing (well, at least one of us does!). > > > > OK, I'll go make it like that. > > Something like so then? Looks good to me, thanks! Will