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

[Rafael J. Wysocki]

On Thursday, August 10, 2017 6:20:55 AM CEST Viresh Kumar 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);
> +
>  	init_irq_work(&sg_policy->irq_work, sugov_irq_work);
>  	mutex_init(&sg_policy->work_lock);
>  
> 

Applied, thanks!