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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 A98C5C6778C for ; Tue, 3 Jul 2018 07:51:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D94524C34 for ; Tue, 3 Jul 2018 07:51:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D94524C34 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933617AbeGCHvD (ORCPT ); Tue, 3 Jul 2018 03:51:03 -0400 Received: from terminus.zytor.com ([198.137.202.136]:55361 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932212AbeGCHvA (ORCPT ); Tue, 3 Jul 2018 03:51:00 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w637oc8P201864 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 3 Jul 2018 00:50:38 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w637ocdL201861; Tue, 3 Jul 2018 00:50:38 -0700 Date: Tue, 3 Jul 2018 00:50:38 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Xunlei Pang Message-ID: Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, bsegall@google.com, xlpang@linux.alibaba.com, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org Reply-To: peterz@infradead.org, mingo@kernel.org, hpa@zytor.com, xlpang@linux.alibaba.com, bsegall@google.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, tglx@linutronix.de In-Reply-To: <20180620101834.24455-2-xlpang@linux.alibaba.com> References: <20180620101834.24455-2-xlpang@linux.alibaba.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/fair: Advance global expiration when period timer is restarted Git-Commit-ID: f1d1be8aee6c461652aea8f58bedebaa73d7f4d3 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f1d1be8aee6c461652aea8f58bedebaa73d7f4d3 Gitweb: https://git.kernel.org/tip/f1d1be8aee6c461652aea8f58bedebaa73d7f4d3 Author: Xunlei Pang AuthorDate: Wed, 20 Jun 2018 18:18:34 +0800 Committer: Ingo Molnar CommitDate: Tue, 3 Jul 2018 09:17:29 +0200 sched/fair: Advance global expiration when period timer is restarted When period gets restarted after some idle time, start_cfs_bandwidth() doesn't update the expiration information, expire_cfs_rq_runtime() will see cfs_rq->runtime_expires smaller than rq clock and go to the clock drift logic, wasting needless CPU cycles on the scheduler hot path. Update the global expiration in start_cfs_bandwidth() to avoid frequent expire_cfs_rq_runtime() calls once a new period begins. Signed-off-by: Xunlei Pang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ben Segall Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180620101834.24455-2-xlpang@linux.alibaba.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 791707c56886..840b92ee6f89 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5204,13 +5204,18 @@ static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) { + u64 overrun; + lockdep_assert_held(&cfs_b->lock); - if (!cfs_b->period_active) { - cfs_b->period_active = 1; - hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period); - hrtimer_start_expires(&cfs_b->period_timer, HRTIMER_MODE_ABS_PINNED); - } + if (cfs_b->period_active) + return; + + cfs_b->period_active = 1; + overrun = hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period); + cfs_b->runtime_expires += (overrun + 1) * ktime_to_ns(cfs_b->period); + cfs_b->expires_seq++; + hrtimer_start_expires(&cfs_b->period_timer, HRTIMER_MODE_ABS_PINNED); } static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)