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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D307BC33C9E for ; Sat, 11 Jan 2020 09:54:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7E5A214D8 for ; Sat, 11 Jan 2020 09:54:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DG1rrq1e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729047AbgAKJyC (ORCPT ); Sat, 11 Jan 2020 04:54:02 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:55161 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728978AbgAKJxy (ORCPT ); Sat, 11 Jan 2020 04:53:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578736433; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=DZxy64tFDfrC2+LuLzWjbCt/f7jnHkWOMjnqxtC1c1o=; b=DG1rrq1eJvDUz0jVOSZLop2y+B4peW4zDtZhhyojRZDXBFX8wneiBm2N0vcyAL1HpdVCx1 /6c8TF/t7vTuHYahsSF9gDyA36QQAp/c2g9E8RohYPOV7H+N0H+7uw3FXas8QHf8/eTA5J OWEVIPpdjogFyd1hBCA6LJFQRXEvLjM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-363-xYX4i7j5MAy-AsEckaf86Q-1; Sat, 11 Jan 2020 04:53:45 -0500 X-MC-Unique: xYX4i7j5MAy-AsEckaf86Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B44BA100550E; Sat, 11 Jan 2020 09:53:41 +0000 (UTC) Received: from intel-purley-fpgabmp-02.ml3.eng.bos.redhat.com (intel-purley-fpgabmp-02.ml3.eng.bos.redhat.com [10.19.176.206]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2290A272A3; Sat, 11 Jan 2020 09:53:41 +0000 (UTC) From: Scott Wood To: Peter Zijlstra , Frederic Weisbecker , Thomas Gleixner , Ingo Molnar Cc: linux-kernel@vger.kernel.org, Scott Wood Subject: [PATCH v2 1/2] sched/core: Don't skip remote tick for idle cpus Date: Sat, 11 Jan 2020 04:53:38 -0500 Message-Id: <1578736419-14628-2-git-send-email-swood@redhat.com> In-Reply-To: <1578736419-14628-1-git-send-email-swood@redhat.com> References: <1578736419-14628-1-git-send-email-swood@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 90e4b00ace89..dfb8ea801700 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3668,22 +3668,24 @@ 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: -- 1.8.3.1