Received: by 2002:a25:c593:0:0:0:0:0 with SMTP id v141csp719450ybe; Thu, 5 Sep 2019 05:03:07 -0700 (PDT) X-Google-Smtp-Source: APXvYqwJBo9fexrCMkyVCIV+/mWtTS6ffutZIPGe2ZXk4SDUXGKAH53MHbTOEb35uGpVqRRsX3vU X-Received: by 2002:a62:388f:: with SMTP id f137mr3364157pfa.131.1567684987709; Thu, 05 Sep 2019 05:03:07 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1567684987; cv=none; d=google.com; s=arc-20160816; b=P/DJJ5RJ5WpHN5vAlxTKIKmAKmI4jyTlN2PlmyL+kSrbSdPP+fuI5V6TT04kQIGXXN DG1c/omGacKkp2B+8P2fMQSJw+s6zxiQCradyKKeEOoofsnnxWFrQq+4Vo3IiLYlpLe+ /uPb0ksRSVcgRgmcuc/qEMEIFEPmx6eikUhweI3QLLbAqvyxCG7/YEAkwwxX3gd8ZpUt n7XxLPiUiC1vgg6zZFkfZAKF3LwlGqLvXNYcWAQzUcz1ds4c6fOviVUzrwEjxM0hisrQ ToFnXfMBhMOuJ0F95vYxxkciBahhcIbAalLzIe2K/Oa6Sg/Zg+pkb8oNUcHadg/2uOMC asoQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:message-id:date:in-reply-to :subject:cc:to:from:user-agent:references; bh=R5s6ii3FMt/iIVGpJQkIu70aOdUkjUPa0sxhdyrOv3k=; b=wMfgIwzVCqfVKEf2O5c8TsZ4seJiH+DjiqC3r/ye8BoKOGpenZ9fVU7B8gjQQdrdFP 2nobe+Oe3h0TZZKLI7vogBhMj2CQuTYIdLnSSe2QlcHq63DBIiJGuHxSfSJy3Dux7VSQ wcPbZ7AAkINJBygLk3ffw/VmameIngxETs25Pev4IkG8qCkkBCm/oFA2hsyEss0XXtDP IoTcHfiy9TJc9y1q9NpGmTnS2mT+At2+nEnmcF1yf9qNlkuiIVxZWDH6rCI8D1yT+JsH ai0/4u08cV+evVAwGVv+EiXlU1Mo9zMImeqbdfSka6meXmlx1hXxOLN8uOADW6VFqkb5 NLqg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 9si1602464pgo.283.2019.09.05.05.02.49; Thu, 05 Sep 2019 05:03:07 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731961AbfIEKR3 (ORCPT + 99 others); Thu, 5 Sep 2019 06:17:29 -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