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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 81FC9C169C4 for ; Mon, 11 Feb 2019 10:52:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59ECC20838 for ; Mon, 11 Feb 2019 10:52:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726969AbfBKKwL (ORCPT ); Mon, 11 Feb 2019 05:52:11 -0500 Received: from terminus.zytor.com ([198.137.202.136]:50349 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725931AbfBKKwL (ORCPT ); Mon, 11 Feb 2019 05:52:11 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x1BApviH3499077 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 11 Feb 2019 02:51:57 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x1BApvYO3499074; Mon, 11 Feb 2019 02:51:57 -0800 Date: Mon, 11 Feb 2019 02:51:57 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Valentin Schneider Message-ID: Cc: hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, valentin.schneider@arm.com, torvalds@linux-foundation.org Reply-To: valentin.schneider@arm.com, torvalds@linux-foundation.org, mingo@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de, hpa@zytor.com In-Reply-To: <20190117153411.2390-4-valentin.schneider@arm.com> References: <20190117153411.2390-4-valentin.schneider@arm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/fair: Prune, fix and simplify the nohz_balancer_kick() comment block Git-Commit-ID: 9f132742d5c4146397fef0c5b09fe220576a5bb2 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: 9f132742d5c4146397fef0c5b09fe220576a5bb2 Gitweb: https://git.kernel.org/tip/9f132742d5c4146397fef0c5b09fe220576a5bb2 Author: Valentin Schneider AuthorDate: Thu, 17 Jan 2019 15:34:09 +0000 Committer: Ingo Molnar CommitDate: Mon, 11 Feb 2019 08:02:18 +0100 sched/fair: Prune, fix and simplify the nohz_balancer_kick() comment block The comment block for that function lists the heuristics for triggering a nohz kick, but the most recent ones (blocked load updates, misfit) aren't included, and some of them (LLC nohz logic, asym packing) are no longer in sync with the code. The conditions are either simple enough or properly commented, so get rid of that list instead of letting it grow. Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Cc: Dietmar.Eggemann@arm.com Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: morten.rasmussen@arm.com Cc: vincent.guittot@linaro.org Link: https://lkml.kernel.org/r/20190117153411.2390-4-valentin.schneider@arm.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ac6b52d8c79e..f44da9b491ff 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9551,15 +9551,8 @@ static void kick_ilb(unsigned int flags) } /* - * Current heuristic for kicking the idle load balancer in the presence - * of an idle cpu in the system. - * - This rq has more than one task. - * - This rq has at least one CFS task and the capacity of the CPU is - * significantly reduced because of RT tasks or IRQs. - * - At parent of LLC scheduler domain level, this cpu's scheduler group has - * multiple busy cpu. - * - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler - * domain span are idle. + * Current decision point for kicking the idle load balancer in the presence + * of idle CPUs in the system. */ static void nohz_balancer_kick(struct rq *rq) {