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Groups > linux.kernel > #1369546
| From | "Rafael J. Wysocki" <rafael@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [Update][PATCH v7 7/7] cpufreq: schedutil: New governor based on scheduler utilization data |
| Date | 2016-04-01 21:20 +0200 |
| Message-ID | <rjcLU-sT-17@gated-at.bofh.it> (permalink) |
| References | <rfjLX-5N2-3@gated-at.bofh.it> <rfjLX-5N2-1@gated-at.bofh.it> <ridAl-6zf-1@gated-at.bofh.it> <rjbmN-7Po-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, Apr 1, 2016 at 7:49 PM, Steve Muckle <steve.muckle@linaro.org> wrote:
> On 03/29/2016 07:00 PM, Rafael J. Wysocki wrote:
> ...
>> +config CPU_FREQ_GOV_SCHEDUTIL
>> + tristate "'schedutil' cpufreq policy governor"
>> + depends on CPU_FREQ
>> + select CPU_FREQ_GOV_ATTR_SET
>> + select IRQ_WORK
>> + help
>> + This governor makes decisions based on the utilization data provided
>> + by the scheduler. It sets the CPU frequency to be proportional to
>> + the utilization/capacity ratio coming from the scheduler. If the
>> + utilization is frequency-invariant, the new frequency is also
>> + proportional to the maximum available frequency. If that is not the
>> + case, it is proportional to the current frequency of the CPU with the
>> + tipping point at utilization/capacity equal to 80%.
>
> This help text implies that the tipping point of 80% applies only to
> non-frequency invariant configurations, rather than both. Possible to
> rephrase?
Sure.
What about:
"If that is not the case, it is proportional to the current frequency
of the CPU. The frequency tipping point is at utilization/capacity
equal to 80% in both cases."
> ...
>> +static unsigned int sugov_next_freq_shared(struct sugov_policy *sg_policy,
>> + unsigned long util, unsigned long max)
>> +{
>> + struct cpufreq_policy *policy = sg_policy->policy;
>> + unsigned int max_f = policy->cpuinfo.max_freq;
>> + u64 last_freq_update_time = sg_policy->last_freq_update_time;
>> + unsigned int j;
>> +
>> + if (util == ULONG_MAX)
>> + return max_f;
>> +
>> + for_each_cpu(j, policy->cpus) {
>> + struct sugov_cpu *j_sg_cpu;
>> + unsigned long j_util, j_max;
>> + u64 delta_ns;
>> +
>> + if (j == smp_processor_id())
>> + continue;
>> +
>> + j_sg_cpu = &per_cpu(sugov_cpu, j);
>> + /*
>> + * If the CPU utilization was last updated before the previous
>> + * frequency update and the time elapsed between the last update
>> + * of the CPU utilization and the last frequency update is long
>> + * enough, don't take the CPU into account as it probably is
>> + * idle now.
>> + */
>> + delta_ns = last_freq_update_time - j_sg_cpu->last_update;
>> + if ((s64)delta_ns > TICK_NSEC)
>
>>> Why not declare delta_ns as an s64 (also in suguv_should_update_freq)
>>> and avoid the cast?
>>
>> I took this from __update_load_avg(), but it shouldn't matter here.
>
> Did you mean to keep these casts?
Not really. I'll fix that up shortly.
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[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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