Re: [PATCH v6 09/16] sched/cpufreq: uclamp: Add utilization clamping for RT tasks

Quentin Perret
2019-01-22T12:30:10Z

On Tuesday 15 Jan 2019 at 10:15:06 (+0000), Patrick Bellasi wrote:
> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> index 520ee2b785e7..38a05a4f78cc 100644
> --- a/kernel/sched/cpufreq_schedutil.c
> +++ b/kernel/sched/cpufreq_schedutil.c
> @@ -201,9 +201,6 @@ unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs,
> unsigned long dl_util, util, irq;
> struct rq *rq = cpu_rq(cpu);
>
> - if (type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt))
> - return max;
> -
> /*
> * Early check to see if IRQ/steal time saturates the CPU, can be
> * because of inaccuracies in how we track these -- see
> @@ -219,15 +216,19 @@ unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs,
> * utilization (PELT windows are synchronized) we can directly add them
> * to obtain the CPU's actual utilization.
> *
> - * CFS utilization can be boosted or capped, depending on utilization
> - * clamp constraints requested by currently RUNNABLE tasks.
> + * CFS and RT utilization can be boosted or capped, depending on
> + * utilization clamp constraints requested by currently RUNNABLE
> + * tasks.
> * When there are no CFS RUNNABLE tasks, clamps are released and
> * frequency will be gracefully reduced with the utilization decay.
> */
> - util = (type == ENERGY_UTIL)
> - ? util_cfs
> - : uclamp_util(rq, util_cfs);
> - util += cpu_util_rt(rq);
> + util = cpu_util_rt(rq);
> + if (type == FREQUENCY_UTIL) {
> + util += cpu_util_cfs(rq);
> + util = uclamp_util(rq, util);

So with this we don't go to max to anymore for CONFIG_UCLAMP_TASK=n no ?

Thanks,
Quentin