Re: [PATCH 03/11] cpufreq/schedutil: use rt utilization tracking

[Viresh Kumar]

On 28-06-18, 17:45, Vincent Guittot wrote:
> Add both cfs and rt utilization when selecting an OPP for cfs tasks as rt
> can preempt and steal cfs's running time.
> 
> rt util_avg is used to take into account the utilization of rt tasks
> on the CPU when selecting OPP. If a rt task migrate, the rt utilization
> will not migrate but will decay over time. On an overloaded CPU, cfs
> utilization reflects the remaining utilization avialable on CPU. When rt
> task migrates, the cfs utilization will increase when tasks will start to
> use the newly available capacity. At the same pace, rt utilization will
> decay and both variations will compensate each other  to keep unchanged
> overall utilization and will prevent any OPP drop.
> 
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> ---
>  kernel/sched/cpufreq_schedutil.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

-- 
viresh