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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 31F6BC3A5A5 for ; Thu, 5 Sep 2019 10:17:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11FFB21743 for ; Thu, 5 Sep 2019 10:17:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731294AbfIEKRa (ORCPT ); Thu, 5 Sep 2019 06:17:30 -0400 Received: from foss.arm.com ([217.140.110.172]:41122 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731142AbfIEKR3 (ORCPT ); Thu, 5 Sep 2019 06:17:29 -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 1121F1576; Thu, 5 Sep 2019 03:17:29 -0700 (PDT) Received: from e110439-lin (e110439-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5CE9B3F718; Thu, 5 Sep 2019 03:17:27 -0700 (PDT) References: <20190830174944.21741-1-subhra.mazumdar@oracle.com> <20190830174944.21741-4-subhra.mazumdar@oracle.com> User-agent: mu4e 1.3.3; emacs 26.2 From: Patrick Bellasi To: subhra mazumdar Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, tglx@linutronix.de, steven.sistare@oracle.com, dhaval.giani@oracle.com, daniel.lezcano@linaro.org, vincent.guittot@linaro.org, viresh.kumar@linaro.org, tim.c.chen@linux.intel.com, mgorman@techsingularity.net, parth@linux.ibm.com Subject: Re: [RFC PATCH 3/9] sched: add sched feature to disable idle core search In-reply-to: <20190830174944.21741-4-subhra.mazumdar@oracle.com> Date: Thu, 05 Sep 2019 11:17:25 +0100 Message-ID: <87mufj2gju.fsf@arm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 30, 2019 at 18:49:38 +0100, subhra mazumdar wrote... > Add a new sched feature SIS_CORE to have an option to disable idle core > search (select_idle_core). > > Signed-off-by: subhra mazumdar > --- > kernel/sched/features.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/sched/features.h b/kernel/sched/features.h > index 858589b..de4d506 100644 > --- a/kernel/sched/features.h > +++ b/kernel/sched/features.h > @@ -57,6 +57,7 @@ SCHED_FEAT(TTWU_QUEUE, true) > */ > SCHED_FEAT(SIS_AVG_CPU, false) > SCHED_FEAT(SIS_PROP, true) > +SCHED_FEAT(SIS_CORE, true) Why do we need a sched_feature? If you think there are systems in which the usage of latency-nice does not make sense for in "Select Idle Sibling", then we should probably better add a new Kconfig option. If that's the case, you can probably use the init/Kconfig's "Scheduler features" section, recently added by: commit 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting") > /* > * Issue a WARN when we do multiple update_rq_clock() calls Best, Patrick -- #include Patrick Bellasi