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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC660C4332F for ; Thu, 10 Nov 2022 11:16:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230379AbiKJLQo (ORCPT ); Thu, 10 Nov 2022 06:16:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230355AbiKJLQc (ORCPT ); Thu, 10 Nov 2022 06:16:32 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4A4297018A for ; Thu, 10 Nov 2022 03:16:30 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 39EBF1FB; Thu, 10 Nov 2022 03:16:36 -0800 (PST) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 11AEE3F534; Thu, 10 Nov 2022 03:16:27 -0800 (PST) Message-ID: Date: Thu, 10 Nov 2022 12:16:26 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [RFC PATCH 0/1] sched/pelt: Change PELT halflife at runtime Content-Language: en-US To: Peter Zijlstra , Kajetan Puchalski Cc: Jian-Min Liu , Ingo Molnar , Vincent Guittot , Morten Rasmussen , Vincent Donnefort , Quentin Perret , Patrick Bellasi , Abhijeet Dharmapurikar , Qais Yousef , linux-kernel@vger.kernel.org, Jonathan JMChen References: <20220829055450.1703092-1-dietmar.eggemann@arm.com> <0f82011994be68502fd9833e499749866539c3df.camel@mediatek.com> From: Dietmar Eggemann In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/11/2022 14:41, Peter Zijlstra wrote: > On Thu, Sep 29, 2022 at 03:41:47PM +0100, Kajetan Puchalski wrote: [...] > @@ -2956,13 +2958,26 @@ static inline unsigned long cpu_util_dl(struct rq *rq) > */ > static inline unsigned long cpu_util_cfs(int cpu) > { > + struct rq *rq = cpu_rq(cpu); > struct cfs_rq *cfs_rq; > unsigned long util; > > - cfs_rq = &cpu_rq(cpu)->cfs; > + cfs_rq = &rq->cfs; > util = READ_ONCE(cfs_rq->avg.util_avg); > > if (sched_feat(UTIL_EST)) { > + if (sched_feat(UTIL_EST_FASTER)) { > + struct task_struct *curr; > + > + rcu_read_lock(); > + curr = rcu_dereference(rq->curr); > + if (likely(curr->sched_class == &fair_sched_class)) { > + u64 runtime = curr->se.sum_exec_runtime - curr->se.exec_start; Don't we and up with gigantic runtime numbers here? oot@juno:~# cat /proc/1676/task/1676/schedstat 36946300 1150620 11 root@juno:~# cat /proc/1676/task/1676/sched rt-app (1676, #threads: 2) ------------------------------------------------------------------- se.exec_start : 77766.964240 <- ! se.vruntime : 563.587883 e.sum_exec_runtime : 36.946300 <- ! se.nr_migrations : 0 ... I expect cpu_util_cfs() to be ~1024 almost all the time now. > + util = max_t(unsigned long, util, > + faster_est_approx(runtime * 2)); > + } > + rcu_read_unlock(); > + } > util = max_t(unsigned long, util, > READ_ONCE(cfs_rq->avg.util_est.enqueued)); > } [...]