Re: [PATCH v3 0/6] cpufreq: schedutil: fixes for flags updates

[Patrick Bellasi <patrick.bellasi@arm.com>]

On 22-Dec 13:10, Peter Zijlstra wrote:
> On Fri, Dec 22, 2017 at 12:46:18PM +0100, Peter Zijlstra wrote:
> > Blergh that'd make a mess of things again.
> 
> Something like so then..
> 
> --- a/kernel/sched/cpufreq_schedutil.c
> +++ b/kernel/sched/cpufreq_schedutil.c
> @@ -187,11 +187,16 @@ static void sugov_get_util(struct sugov_
>  
>  static unsigned long sugov_aggregate_util(struct sugov_cpu *sg_cpu)
>  {
> -	unsigned long util = sg_cpu->util_cfs + sg_cpu->util_dl;
>  	struct rq *rq = cpu_rq(sg_cpu->cpu);
> +	unsigned long util;
>  
> -	if (rq->rt.rt_nr_running)
> +	if (rq->rt.rt_nr_running) {
>  		util = sg_cpu->max;
> +	} else {
> +		util = sg_cpu->util_dl;
> +		if (rq->cfs.h_nr_running)
> +			util += sg_cpu->util_cfs;

Since sugov_aggregate_util always follow sugov_get_util, maybe we
can move these checks into the latter and remove the first one?

That way, sg_cpu->util_{dl,rt,cfs} will always report exactly the
requests of each class considering also which tasks are RUNNABLE at
sugov_get_util time.

Still the observation of Juri is valid: do we wanna really disregard
all the CFS blocked load as soon as there are not CFS tasks?

> +	}
>  
>  	/*
>  	 * Ideally we would like to set util_dl as min/guaranteed freq and

-- 
#include <best/regards.h>

Patrick Bellasi