All of lore.kernel.org
 help / color / mirror / Atom feed
From: Patrick Bellasi <patrick.bellasi@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	Ingo Molnar <mingo@redhat.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Todd Kjos <tkjos@android.com>, Joel Fernandes <joelaf@google.com>
Subject: Re: [PATCH v3 0/6] cpufreq: schedutil: fixes for flags updates
Date: Fri, 22 Dec 2017 11:02:06 +0000	[thread overview]
Message-ID: <20171222110206.GA6414@e110439-lin> (raw)
In-Reply-To: <20171222100626.7g5yklspjofcp2we@hirez.programming.kicks-ass.net>

On 22-Dec 11:06, Peter Zijlstra wrote:
> On Wed, Dec 20, 2017 at 06:38:14PM +0100, Juri Lelli wrote:
> > On 20/12/17 16:30, Peter Zijlstra wrote:
> > 
> > [...]
> > 
> > > @@ -327,12 +331,7 @@ static unsigned int sugov_next_freq_shar
> > >  		if (delta_ns > TICK_NSEC) {
> > >  			j_sg_cpu->iowait_boost = 0;
> > >  			j_sg_cpu->iowait_boost_pending = false;
> > > -			j_sg_cpu->util_cfs = 0;
> > > -			if (j_sg_cpu->util_dl == 0)
> > > -				continue;
> > >  		}
> > 
> > This goes away because with Brendan/Vincent fix we don't need the
> > workaround for stale CFS util contribution for idle CPUs anymore?
> 
> An easy fix would be something like the below I suppose (also folded a
> change from Viresh).
> 
> This way it completely ignores the demand from idle CPUs. Which I
> suppose is exactly what you want, no?
> 
> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> index ab84d2261554..9736b537386a 100644
> --- a/kernel/sched/cpufreq_schedutil.c
> +++ b/kernel/sched/cpufreq_schedutil.c
> @@ -315,8 +315,8 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
>  		unsigned long j_util, j_max;
>  		s64 delta_ns;
>  
> -		if (j_sg_cpu != sg_cpu)
> -			sugov_get_util(j_sg_cpu);
> +		if (idle_cpu(j))
> +			continue;

That should work to skip IDLE CPUs... however I'm missing where now we
get the sugov_get_util(j_sg_cpu) for active CPUs. It has been moved
somewhere else I guess...

Moreover, that way don't we completely disregard CFS blocked load for
IDLE CPUs... as well as DL reserved utilization, which should be
released only at the 0-lag time?

>  
>  		/*
>  		 * If the CFS CPU utilization was last updated before the
> @@ -354,7 +354,6 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time,
>  
>  	raw_spin_lock(&sg_policy->update_lock);
>  
> -	sugov_get_util(sg_cpu);
>  	sugov_set_iowait_boost(sg_cpu, time, flags);
>  	sg_cpu->last_update = time;
>  

-- 
#include <best/regards.h>

Patrick Bellasi

  reply	other threads:[~2017-12-22 11:02 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-30 11:47 [PATCH v3 0/6] cpufreq: schedutil: fixes for flags updates Patrick Bellasi
2017-11-30 11:47 ` [PATCH v3 1/6] cpufreq: schedutil: reset sg_cpus's flags at IDLE enter Patrick Bellasi
2017-11-30 13:12   ` Juri Lelli
2017-11-30 15:41     ` Patrick Bellasi
2017-11-30 16:02       ` Juri Lelli
2017-11-30 16:19         ` Patrick Bellasi
2017-11-30 16:45           ` Juri Lelli
2017-12-07  5:01   ` Viresh Kumar
2017-12-07 12:45     ` Patrick Bellasi
2017-12-07 15:55       ` Dietmar Eggemann
2017-12-12 11:37       ` Viresh Kumar
2017-12-12 13:38         ` Juri Lelli
2017-12-12 14:40           ` Viresh Kumar
2017-12-12 14:56             ` Juri Lelli
2017-12-12 15:18               ` Patrick Bellasi
2017-12-12 15:16         ` Patrick Bellasi
2017-12-13  9:06           ` Viresh Kumar
2017-12-20 14:33   ` Peter Zijlstra
2017-12-20 14:51     ` Patrick Bellasi
2017-11-30 11:47 ` [PATCH v3 2/6] cpufreq: schedutil: ensure max frequency while running RT/DL tasks Patrick Bellasi
2017-11-30 13:17   ` Juri Lelli
2017-11-30 15:45     ` Patrick Bellasi
2017-11-30 16:03       ` Juri Lelli
2017-12-07  5:05   ` Viresh Kumar
2017-12-07 14:18     ` Patrick Bellasi
2017-11-30 11:47 ` [PATCH v3 3/6] cpufreq: schedutil: update CFS util only if used Patrick Bellasi
2017-11-30 13:22   ` Juri Lelli
2017-11-30 15:57     ` Patrick Bellasi
2017-12-07  5:15       ` Viresh Kumar
2017-12-07 14:19         ` Patrick Bellasi
2017-12-14  4:45           ` Viresh Kumar
2017-11-30 11:47 ` [PATCH v3 4/6] sched/rt: fast switch to maximum frequency when RT tasks are scheduled Patrick Bellasi
2017-11-30 13:28   ` Juri Lelli
2017-12-06  9:39   ` Vincent Guittot
2017-12-06 11:38     ` Patrick Bellasi
2017-12-06 12:36       ` Vincent Guittot
2017-11-30 11:47 ` [PATCH v3 5/6] cpufreq: schedutil: relax rate-limiting while running RT/DL tasks Patrick Bellasi
2017-11-30 13:36   ` Juri Lelli
2017-11-30 15:54     ` Patrick Bellasi
2017-11-30 16:06       ` Juri Lelli
2017-11-30 11:47 ` [PATCH v3 6/6] cpufreq: schedutil: ignore sugov kthreads Patrick Bellasi
2017-11-30 13:41   ` Juri Lelli
2017-11-30 16:02     ` Patrick Bellasi
2017-11-30 16:12       ` Juri Lelli
2017-11-30 16:42         ` Patrick Bellasi
2017-12-07  9:24           ` Viresh Kumar
2017-12-07 15:47             ` Patrick Bellasi
2017-12-20 15:30 ` [PATCH v3 0/6] cpufreq: schedutil: fixes for flags updates Peter Zijlstra
2017-12-20 15:43   ` Peter Zijlstra
2017-12-21  9:15     ` Viresh Kumar
2017-12-21 10:25       ` Peter Zijlstra
2017-12-21 10:30         ` Viresh Kumar
2017-12-21 10:39           ` Peter Zijlstra
2017-12-21 10:43             ` Viresh Kumar
2017-12-22  8:30               ` Peter Zijlstra
2017-12-20 15:56   ` Peter Zijlstra
2017-12-31  9:43     ` Claudio Scordino
2018-01-02 13:31       ` Claudio Scordino
2017-12-20 17:38   ` Juri Lelli
2017-12-20 18:16     ` Peter Zijlstra
2017-12-22 10:06     ` Peter Zijlstra
2017-12-22 11:02       ` Patrick Bellasi [this message]
2017-12-22 11:46         ` Peter Zijlstra
2017-12-22 12:07           ` Juri Lelli
2017-12-22 12:14             ` Patrick Bellasi
2017-12-22 12:22               ` Peter Zijlstra
2017-12-22 12:07           ` Patrick Bellasi
2017-12-22 12:19             ` Peter Zijlstra
2017-12-22 12:27               ` Juri Lelli
2017-12-22 12:38               ` Patrick Bellasi
2017-12-22 12:43                 ` Juri Lelli
2017-12-22 12:50                   ` Patrick Bellasi
2017-12-22 13:01                     ` Juri Lelli
2017-12-22 12:10           ` Peter Zijlstra
2017-12-22 12:25             ` Patrick Bellasi
2017-12-21  7:34   ` Viresh Kumar
2018-02-06 10:55   ` Claudio Scordino
2018-02-06 15:43     ` Patrick Bellasi
2018-02-06 18:14       ` Claudio Scordino
2018-02-06 18:36         ` Patrick Bellasi
2018-02-08 16:14           ` Claudio Scordino

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20171222110206.GA6414@e110439-lin \
    --to=patrick.bellasi@arm.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=joelaf@google.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=morten.rasmussen@arm.com \
    --cc=peterz@infradead.org \
    --cc=rafael.j.wysocki@intel.com \
    --cc=tkjos@android.com \
    --cc=vincent.guittot@linaro.org \
    --cc=viresh.kumar@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.