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Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on scheduler utilization data

From Steve Muckle <steve.muckle@linaro.org>
Newsgroups linux.kernel
Subject Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on scheduler utilization data
Date 2016-03-31 03:50 +0200
Message-ID <rizUe-5Lv-3@gated-at.bofh.it> (permalink)
References (2 earlier) <ridAl-6zf-1@gated-at.bofh.it> <rih1f-Mt-7@gated-at.bofh.it> <rimDE-4Gg-15@gated-at.bofh.it> <rirN1-87-41@gated-at.bofh.it> <ris6l-fc-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On 03/30/2016 10:24 AM, Rafael J. Wysocki wrote:
> On Wed, Mar 30, 2016 at 7:05 PM, Steve Muckle <steve.muckle@linaro.org> wrote:
>> On 03/30/2016 04:31 AM, Rafael J. Wysocki wrote:
>>>>>>> +static int sugov_limits(struct cpufreq_policy *policy)
>>>>>>> +{
>>>>>>> +     struct sugov_policy *sg_policy = policy->governor_data;
>>>>>>> +
>>>>>>> +     if (!policy->fast_switch_enabled) {
>>>>>>> +             mutex_lock(&sg_policy->work_lock);
>>>>>>> +
>>>>>>> +             if (policy->max < policy->cur)
>>>>>>> +                     __cpufreq_driver_target(policy, policy->max,
>>>>>>> +                                             CPUFREQ_RELATION_H);
>>>>>>> +             else if (policy->min > policy->cur)
>>>>>>> +                     __cpufreq_driver_target(policy, policy->min,
>>>>>>> +                                             CPUFREQ_RELATION_L);
>>>>>>> +
>>>>>>> +             mutex_unlock(&sg_policy->work_lock);
>>>>>>> +     }
>>>>>>> +
>>>>>>> +     sg_policy->need_freq_update = true;
>>>>>
>>>>> I am wondering why we need to do this for !fast_switch_enabled case?
>>>
>>> That will cause the rate limit to be ignored in the utilization update
>>> handler which may be necessary if it is set to a relatively large
>>> value (like 1 s).
>>
>> But why is that necessary for !fast_switch_enabled? In that case the
>> frequency has been adjusted to satisfy the new limits here, so ignoring
>> the rate limit shouldn't be necessary. In other words why not
>>
>> } else {
>>         sg_policy->need_freq_update = true;
>> }
> 
> My thinking here was that the governor might decide to use something
> different from the limit enforced here, so it would be good to make it
> do so as soon as possible.  In particular in the
> non-frequency-invariant utilization case in which new frequency
> depends on the current one.
> 
> That said i'm not particularly opposed to making that change if that's
> preferred.

Ah ok fair enough. No strong opinion from me...

thanks,
Steve

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Thread

[PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on scheduler utilization data "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-22 03:00 +0100
  Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-03-26 02:20 +0100
    Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-26 03:10 +0100
      Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-27 03:40 +0200
        Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-03-28 20:20 +0200
          Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on scheduler utilization data "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-29 14:30 +0200
          Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Peter Zijlstra <peterz@infradead.org> - 2016-03-31 14:30 +0200
            Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-31 14:40 +0200
              Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-04-01 20:20 +0200
  Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-28 11:10 +0200
    Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on scheduler utilization data "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-29 15:00 +0200
      Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-30 03:20 +0200
        Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Peter Zijlstra <peterz@infradead.org> - 2016-03-31 14:30 +0200
      Re: [PATCH v6 7/7][Resend] cpufreq: schedutil: New governor based on  scheduler utilization data Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-30 06:20 +0200
  [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on scheduler utilization data "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-30 04:00 +0200
    Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-30 07:40 +0200
      Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-30 13:40 +0200
        Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-03-30 19:10 +0200
          Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-30 19:30 +0200
            Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-03-31 03:50 +0200
    Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Peter Zijlstra <peterz@infradead.org> - 2016-03-31 14:20 +0200
      Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-31 14:20 +0200
        Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Peter Zijlstra <peterz@infradead.org> - 2016-03-31 14:50 +0200
    Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Peter Zijlstra <peterz@infradead.org> - 2016-03-31 14:50 +0200
    Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-04-01 19:50 +0200
      Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-01 21:20 +0200
        Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-04-01 21:30 +0200
    [Update][PATCH v8 7/7] cpufreq: schedutil: New governor based on scheduler utilization data "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-04-02 01:10 +0200
      Re: [Update][PATCH v8 7/7] cpufreq: schedutil: New governor based on  scheduler utilization data Steve Muckle <steve.muckle@linaro.org> - 2016-04-02 03:10 +0200

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