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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 8A54BC2BB9A for ; Tue, 15 Dec 2020 14:49:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 597E522525 for ; Tue, 15 Dec 2020 14:49:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730030AbgLOOtW (ORCPT ); Tue, 15 Dec 2020 09:49:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:51320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729956AbgLOOsl (ORCPT ); Tue, 15 Dec 2020 09:48:41 -0500 Date: Tue, 15 Dec 2020 15:47:57 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608043680; bh=3serOWbyduZ2yrQbYJh0/hEbtH+9UG4Dr9BcYAGBeqA=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=hZDbF8Cp0tEi+xQnWRVpV2gn1IsachLysLi0EIJzxG8jZlb9h1ovM6KFaNQRSAg6o 22xVSm3cfy90+ASODJZiO3Ncxn9AJLR1swvS/W981PG5YHEc6cBoAcPUfe2iLFFvMY QVUykC9x7/wxjs9UcBB61d68YmVgY4ELJwdqf5N8f2Fl8v/v/OxPr8EHITvsvh81os EBO7dkVjNlKRmJoUKrUXBgyGDLzWSLknnFC7eyGcU5m6YV9H/V8cRY4xs9ZKAz18m1 pR36JbXG/nWBOVR8feySxf4n5u69WfpGwSRyxQpqKFKRHqpiuZ3gr5C1944GU/7CP/ pwFyY8CXW9nEQ== From: Frederic Weisbecker To: Yunfeng Ye Cc: fweisbec@gmail.com, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, Shiyuan Hu , Hewenliang Subject: Re: [PATCH] tick/nohz: Make the idle_exittime update correctly Message-ID: <20201215144757.GA9391@lothringen> References: <2e194669-c074-069c-4fda-ad5bc313a611@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 15, 2020 at 08:06:34PM +0800, Yunfeng Ye wrote: > The idle_exittime field of tick_sched is used to record the time when > the idle state was left. but currently the idle_exittime is updated in > the function tick_nohz_restart_sched_tick(), which is not always in idle > state when nohz_full is configured. > > tick_irq_exit > tick_nohz_irq_exit > tick_nohz_full_update_tick > tick_nohz_restart_sched_tick > ts->idle_exittime = now; > > So move to tick_nohz_stop_idle() to make the idle_exittime update > correctly. > > Signed-off-by: Yunfeng Ye > --- > kernel/time/tick-sched.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > index 749ec2a583de..be2e5d772d50 100644 > --- a/kernel/time/tick-sched.c > +++ b/kernel/time/tick-sched.c > @@ -591,6 +591,7 @@ static void tick_nohz_stop_idle(struct tick_sched *ts, ktime_t now) > { > update_ts_time_stats(smp_processor_id(), ts, now, NULL); > ts->idle_active = 0; > + ts->idle_exittime = now; This changes a bit the meaning of idle_exittime then since this is also called from idle interrupt entry. __tick_nohz_idle_restart_tick() would be a better place. Thanks. > > sched_clock_idle_wakeup_event(); > } > @@ -901,7 +902,6 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now) > * Cancel the scheduled timer and restore the tick > */ > ts->tick_stopped = 0; > - ts->idle_exittime = now; > > tick_nohz_restart(ts, now); > } > -- > 2.18.4 >