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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 746C4C3A5A3 for ; Tue, 27 Aug 2019 10:37:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 45EA7206BB for ; Tue, 27 Aug 2019 10:37:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729100AbfH0Kho (ORCPT ); Tue, 27 Aug 2019 06:37:44 -0400 Received: from foss.arm.com ([217.140.110.172]:42494 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbfH0Khn (ORCPT ); Tue, 27 Aug 2019 06:37:43 -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 1640E28; Tue, 27 Aug 2019 03:37:41 -0700 (PDT) Received: from [192.168.0.9] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8B0B53F718; Tue, 27 Aug 2019 03:37:39 -0700 (PDT) Subject: Re: [PATCH 12/15] sched,fair: flatten update_curr functionality To: Rik van Riel , linux-kernel@vger.kernel.org Cc: kernel-team@fb.com, pjt@google.com, peterz@infradead.org, mingo@redhat.com, morten.rasmussen@arm.com, tglx@linutronix.de, mgorman@techsingularity.net, vincent.guittot@linaro.org References: <20190822021740.15554-1-riel@surriel.com> <20190822021740.15554-13-riel@surriel.com> From: Dietmar Eggemann Message-ID: <63f17078-b467-b239-2824-a0f9b9d14537@arm.com> Date: Tue, 27 Aug 2019 12:37:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190822021740.15554-13-riel@surriel.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 22/08/2019 04:17, Rik van Riel wrote: > Make it clear that update_curr only works on tasks any more. > > There is no need for task_tick_fair to call it on every sched entity up > the hierarchy, so move the call out of entity_tick. > > Signed-off-by: Rik van Riel ` > Signed-off-by: Rik van Riel > --- > kernel/sched/fair.c | 24 +++++++++++------------- > 1 file changed, 11 insertions(+), 13 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index fa8e88731821..5cfa3dbeba49 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -872,10 +872,11 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) > static void update_curr(struct cfs_rq *cfs_rq) > { > struct sched_entity *curr = cfs_rq->curr; > + struct task_struct *curtask; > u64 now = rq_clock_task(rq_of(cfs_rq)); > u64 delta_exec; > > - if (unlikely(!curr)) > + if (unlikely(!curr) || !entity_is_task(curr)) > return; Shouldn't this be - if (unlikely(!curr) || !entity_is_task(curr)) + if (unlikely(!curr)) return; + BUG_ON(!entity_is_task(curr)); IMHO, cfs_rq->curr can only be a task with your changes.