Re: [PATCH v5 05/10] cpufreq/schedutil: get max utilization

[Quentin Perret <quentin.perret@arm.com>]

Hi Vincent,

On Friday 25 May 2018 at 15:12:26 (+0200), Vincent Guittot wrote:
> Now that we have both the dl class bandwidth requirement and the dl class
> utilization, we can use the max of the 2 values when agregating the
> utilization of the CPU.
> 
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
>  kernel/sched/sched.h | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index 4526ba6..0eb07a8 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -2194,7 +2194,11 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
>  #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
>  static inline unsigned long cpu_util_dl(struct rq *rq)
>  {
> -	return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
> +	unsigned long util = (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
> +
> +	util = max_t(unsigned long, util, READ_ONCE(rq->avg_dl.util_avg));

Would it make sense to use a UTIL_EST version of that signal here ? I
don't think that would make sense for the RT class with your patch-set
since you only really use the blocked part of the signal for RT IIUC,
but would that work for DL ?
> +
> +	return util;
>  }
>  
>  static inline unsigned long cpu_util_cfs(struct rq *rq)
> -- 
> 2.7.4
>