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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 B8BC5C282D8 for ; Fri, 1 Feb 2019 15:08:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8188520855 for ; Fri, 1 Feb 2019 15:08:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730199AbfBAPH7 (ORCPT ); Fri, 1 Feb 2019 10:07:59 -0500 Received: from foss.arm.com ([217.140.101.70]:33084 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729043AbfBAPH6 (ORCPT ); Fri, 1 Feb 2019 10:07:58 -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 EF41080D; Fri, 1 Feb 2019 07:07:57 -0800 (PST) Received: from [10.1.194.37] (e113632-lin.cambridge.arm.com [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 90E1C3F589; Fri, 1 Feb 2019 07:07:55 -0800 (PST) Subject: Re: [PATCH v4 00/10] steal tasks to improve CPU utilization From: Valentin Schneider To: Steve 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> Message-ID: Date: Fri, 1 Feb 2019 15:07:53 +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: 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 20:30, Valentin Schneider wrote: [...] > ----->8----- > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 17ab4db..8b5172f 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -7152,7 +7152,8 @@ done: __maybe_unused; > rq_idle_stamp_update(rq); > > new_tasks = idle_balance(rq, rf); > - if (new_tasks == 0) > + if (new_tasks == 0 && > + (!static_key_unlikely(&sched_energy_present) || READ_ONCE(rq->rd->overutilized)) > new_tasks = try_steal(rq, rf); > > if (new_tasks) > -----8<----- > As a heads-up, that should now use sched_energy_enabled() [1], so that'd be: -----8<----- diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f28df187db24..2eddb40fd368 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7134,7 +7134,8 @@ done: __maybe_unused; rq_idle_stamp_update(rq); new_tasks = idle_balance(rq, rf); - if (new_tasks == 0) + if (new_tasks == 0 && + (!sched_energy_enabled() || READ_ONCE(rq->rd->overutilized))) new_tasks = try_steal(rq, rf); if (new_tasks) ----->8----- [1]: f8a696f25ba0 ("sched/core: Give DCE a fighting chance") [...]