Re: [PATCH 1/2] cpufreq: schedutil: Don't restrict kthread to related_cpus unnecessarily

From: Pavan Kondeti
Date: Thu Aug 10 2017 - 02:58:40 EST


On Thu, Aug 10, 2017 at 9:50 AM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> Utilization update callbacks are now processed remotely, even on the
> CPUs that don't share cpufreq policy with the target CPU (if
> dvfs_possible_from_any_cpu flag is set).
>
> But in non-fast switch paths, the frequency is changed only from one of
> policy->related_cpus. This happens because the kthread which does the
> actual update is bound to a subset of CPUs (i.e. related_cpus).
>
> Allow frequency to be remotely updated as well (i.e. call
> __cpufreq_driver_target()) if dvfs_possible_from_any_cpu flag is set.
>
> Reported-by: Pavan Kondeti <pkondeti@xxxxxxxxxxxxxx>
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> ---
> kernel/sched/cpufreq_schedutil.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> index 2e74c49776be..504d0752f8f2 100644
> --- a/kernel/sched/cpufreq_schedutil.c
> +++ b/kernel/sched/cpufreq_schedutil.c
> @@ -487,7 +487,11 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy)
> }
>
> sg_policy->thread = thread;
> - kthread_bind_mask(thread, policy->related_cpus);
> +
> + /* Kthread is bound to all CPUs by default */
> + if (!policy->dvfs_possible_from_any_cpu)
> + kthread_bind_mask(thread, policy->related_cpus);
> +

LGTM. Your other patch in this series is also nice. Thanks for doing it.

Thanks,
Pavan

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