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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 1D5A4C04EB8 for ; Sat, 8 Dec 2018 18:33:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D69CE20700 for ; Sat, 8 Dec 2018 18:33:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D69CE20700 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726222AbeLHSdc (ORCPT ); Sat, 8 Dec 2018 13:33:32 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:34212 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbeLHSdc (ORCPT ); Sat, 8 Dec 2018 13:33:32 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E386CEBD; Sat, 8 Dec 2018 10:33:31 -0800 (PST) Received: from [10.0.2.15] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 34C513F575; Sat, 8 Dec 2018 10:33:28 -0800 (PST) Subject: Re: [PATCH v4 03/10] sched/topology: Provide cfs_overload_cpus bitmap To: Steven Sistare , mingo@redhat.com, peterz@infradead.org Cc: subhra.mazumdar@oracle.com, dhaval.giani@oracle.com, daniel.m.jordan@oracle.com, pavel.tatashin@microsoft.com, matt@codeblueprint.co.uk, umgwanakikbuti@gmail.com, riel@redhat.com, jbacik@fb.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, quentin.perret@arm.com, linux-kernel@vger.kernel.org References: <1544131696-2888-1-git-send-email-steven.sistare@oracle.com> <1544131696-2888-4-git-send-email-steven.sistare@oracle.com> <9253783d-d53f-9587-61eb-2505bca5fc0c@arm.com> <5c145b18-773d-756d-b0b9-1b939c441bd6@oracle.com> From: Valentin Schneider Message-ID: <42abaaa5-6e3e-7362-7622-565f98e9629f@arm.com> Date: Sat, 8 Dec 2018 18:33:19 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <5c145b18-773d-756d-b0b9-1b939c441bd6@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/12/2018 22:35, Steven Sistare wrote: [...] >>> + if (!sds->cfs_overload_cpus) { >>> + mask = sparsemask_alloc_node(nr_cpu_ids, 3, flags, nid); >> ^^^^^^^^^^ ^^^ >> (1) (2) >> >> (1): Is this necessary? Wouldn't cpumask_weight(span) suffice? > > weight does not work because the ids are not consecutive. As a future > optimization I have a patch that computes a local CPU id within the LLC > and uses that as the bitmap index, and that uses weight. For this first > series I am keeping things simple. > Oh, duh, non-contiguous spans strike again. Fair enough! [...]