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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 3FB02C4332D for ; Thu, 19 Mar 2020 10:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E3A220739 for ; Thu, 19 Mar 2020 10:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726901AbgCSK2v (ORCPT ); Thu, 19 Mar 2020 06:28:51 -0400 Received: from foss.arm.com ([217.140.110.172]:33004 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726802AbgCSK2t (ORCPT ); Thu, 19 Mar 2020 06:28:49 -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 7A30631B; Thu, 19 Mar 2020 03:28:49 -0700 (PDT) Received: from [192.168.1.19] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 800C33F305; Thu, 19 Mar 2020 03:28:48 -0700 (PDT) From: Dietmar Eggemann Subject: Re: [PATCH v2 3/9] sched: Remove checks against SD_LOAD_BALANCE To: Valentin Schneider , linux-kernel@vger.kernel.org Cc: mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org References: <20200311181601.18314-1-valentin.schneider@arm.com> <20200311181601.18314-4-valentin.schneider@arm.com> Message-ID: Date: Thu, 19 Mar 2020 11:28:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200311181601.18314-4-valentin.schneider@arm.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 11.03.20 19:15, Valentin Schneider wrote: > Potential users of that flag could have been cpusets and isolcpus. > > cpusets don't need it because they define exclusive (i.e. non-overlapping) > domain spans, see cpuset.cpu_exclusive and cpuset.sched_load_balance. > If such a cpuset contains a single CPU, it will have the NULL domain > attached to it. If it contains several CPUs, none of their domains will > extend beyond the span of the cpuset. There are also non-exclusive cpusets but I assume the statement is the same. CPUs which are only used in cpusets with cpuset.sched_load_balance=0 are attached to the NULL sched-domain. There seems to be no code which alters the SD_LOAD_BALANCE flag. [...]