linux-kernel - Re: [PATCH 1/4] sched/fair: Be less aggressive in calling cpufreq_update

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Message-ID: <20231210205156.kausxdcwsydggwie@airbuntu>
Date:   Sun, 10 Dec 2023 20:51:56 +0000
From:   Qais Yousef <qyousef@...alina.io>
To:     Lukasz Luba <lukasz.luba@....com>
Cc:     linux-kernel@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        linux-pm@...r.kernel.org, Ingo Molnar <mingo@...nel.org>,
        Wei Wang <wvw@...gle.com>, Rick Yiu <rickyiu@...gle.com>,
        Chung-Kai Mei <chungkai@...gle.com>,
        Hongyan Xia <hongyan.xia2@....com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH 1/4] sched/fair: Be less aggressive in calling
 cpufreq_update_util()

On 12/08/23 10:05, Lukasz Luba wrote:
> Hi Qais,
> 
> On 12/8/23 01:52, Qais Yousef wrote:
> 
> [snip]
> 
> > @@ -6704,14 +6677,6 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
> >   	 */
> >   	util_est_enqueue(&rq->cfs, p);
> > -	/*
> > -	 * If in_iowait is set, the code below may not trigger any cpufreq
> > -	 * utilization updates, so do it here explicitly with the IOWAIT flag
> > -	 * passed.
> > -	 */
> > -	if (p->in_iowait)
> > -		cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT);
> > -
> 
> Why this io wait boost is considered as the $subject says 'aggressive'
> calling?

This will trigger a frequency update along with the iowait boost. Did I miss
something?


Cheers

--
Qais Yousef