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Groups > linux.kernel > #1678209
| From | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH V2 3/4] intel_pstate: Ignore scheduler cpufreq callbacks on remote CPUs |
| Date | 2017-06-29 23:30 +0200 |
| Message-ID | <tXPaG-4Ds-19@gated-at.bofh.it> (permalink) |
| References | <tXAbE-3uh-3@gated-at.bofh.it> <tXAbF-3uh-33@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, 2017-06-29 at 10:56 +0530, Viresh Kumar wrote:
> From: Steve Muckle <smuckle.linux@gmail.com>
>
> In preparation for the scheduler cpufreq callback happening on remote
> CPUs, check for this case in intel_pstate which currently requires
> the
> callback run on the local CPU. Such callbacks are ignored for now.
Is it possible that we miss a chance to calculate load periodically at
a predefined interval (10ms default), because the callback happened on
a different CPU?
Thanks,
Srinivas
>
> Signed-off-by: Steve Muckle <smuckle.linux@gmail.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> drivers/cpufreq/intel_pstate.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/cpufreq/intel_pstate.c
> b/drivers/cpufreq/intel_pstate.c
> index 4ce501148790..7a2a8ee579ef 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -1755,6 +1755,9 @@ static void intel_pstate_update_util(struct
> update_util_data *data, u64 time,
> struct cpudata *cpu = container_of(data, struct cpudata,
> update_util);
> u64 delta_ns;
>
> + if (smp_processor_id() != data->cpu)
> + return;
> +
> if (flags & SCHED_CPUFREQ_IOWAIT) {
> cpu->iowait_boost = int_tofp(1);
> } else if (cpu->iowait_boost) {
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[PATCH V2 0/4] sched: cpufreq: Allow remote callbacks Viresh Kumar <viresh.kumar@linaro.org> - 2017-06-29 07:30 +0200
[PATCH V2 3/4] intel_pstate: Ignore scheduler cpufreq callbacks on remote CPUs Viresh Kumar <viresh.kumar@linaro.org> - 2017-06-29 07:30 +0200
Re: [PATCH V2 3/4] intel_pstate: Ignore scheduler cpufreq callbacks on remote CPUs Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2017-06-29 23:30 +0200
Re: [PATCH V2 3/4] intel_pstate: Ignore scheduler cpufreq callbacks on remote CPUs Viresh Kumar <viresh.kumar@linaro.org> - 2017-06-30 05:30 +0200
Re: [PATCH V2 0/4] sched: cpufreq: Allow remote callbacks "Rafael J. Wysocki" <rafael@kernel.org> - 2017-06-29 22:40 +0200
Re: [PATCH V2 0/4] sched: cpufreq: Allow remote callbacks Viresh Kumar <viresh.kumar@linaro.org> - 2017-06-30 05:30 +0200
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