From patchwork Tue Mar 3 17:42:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229985 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 75DC2C3F2C6 for ; Tue, 3 Mar 2020 17:59:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46A9A206D5 for ; Tue, 3 Mar 2020 17:59:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258384; bh=dj1HLVWtS06vubJbJJPoUV4zTCw6tLtJL83/NG1u1nE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=t89PqAWHHZaRKWq+bQqpDUjDhPF9v7NFMIyplYcO34L15FGcgT1sPDSfYvlBVf3U+ Uu03OtiFvvaA7xR3nQnhqHKZOnjKMNS+Lt3ldtbaSDh28V3wzIklrpKeCtJY5I1rNf mTiSMv6HKYo/5YL7ZevA9WNU9u7VVgSb3pePrTns= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387646AbgCCR7l (ORCPT ); Tue, 3 Mar 2020 12:59:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:43062 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387643AbgCCR7k (ORCPT ); Tue, 3 Mar 2020 12:59:40 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F287C2072D; Tue, 3 Mar 2020 17:59:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258380; bh=dj1HLVWtS06vubJbJJPoUV4zTCw6tLtJL83/NG1u1nE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v78R/8GkdSLLIWIS6uLUgcvIBybKQ8h0ddx+9y0hjB+h/Uas6iI6XOHaeUP9BFVPX 39yeTGE1Ndp/rnUNgoHZKHywaGy9trLWAK6X/LBMLkoIPqWgexffyjr5Ql5UXgLc2M NtqW1l7TBBV2bbOMVZyI2ynh1obcbPsPnux8sMXw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Scott Wood , "Peter Zijlstra (Intel)" , Ingo Molnar , Sasha Levin Subject: [PATCH 4.19 05/87] sched/core: Dont skip remote tick for idle CPUs Date: Tue, 3 Mar 2020 18:42:56 +0100 Message-Id: <20200303174349.478213998@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174349.075101355@linuxfoundation.org> References: <20200303174349.075101355@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Scott Wood [ Upstream commit 488603b815a7514c7009e6fc339d74ed4a30f343 ] This will be used in the next patch to get a loadavg update from nohz cpus. The delta check is skipped because idle_sched_class doesn't update se.exec_start. Signed-off-by: Scott Wood Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/1578736419-14628-2-git-send-email-swood@redhat.com Signed-off-by: Sasha Levin --- kernel/sched/core.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2befd2c4ce9e6..3c7e039eae9a1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3117,22 +3117,24 @@ static void sched_tick_remote(struct work_struct *work) * statistics and checks timeslices in a time-independent way, regardless * of when exactly it is running. */ - if (idle_cpu(cpu) || !tick_nohz_tick_stopped_cpu(cpu)) + if (!tick_nohz_tick_stopped_cpu(cpu)) goto out_requeue; rq_lock_irq(rq, &rf); curr = rq->curr; - if (is_idle_task(curr) || cpu_is_offline(cpu)) + if (cpu_is_offline(cpu)) goto out_unlock; update_rq_clock(rq); - delta = rq_clock_task(rq) - curr->se.exec_start; - /* - * Make sure the next tick runs within a reasonable - * amount of time. - */ - WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); + if (!is_idle_task(curr)) { + /* + * Make sure the next tick runs within a reasonable + * amount of time. + */ + delta = rq_clock_task(rq) - curr->se.exec_start; + WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); + } curr->sched_class->task_tick(rq, curr, 0); out_unlock: