Hi,
On 30/11/17 11:47, Patrick Bellasi wrote:
[...]
> diff --git a/kernel/sched/cpufreq_schedutil.c
> b/kernel/sched/cpufreq_schedutil.c
> index 2f52ec0f1539..67339ccb5595 100644
> --- a/kernel/sched/cpufreq_schedutil.c
> +++ b/kernel/sched/cpufreq_schedutil.c
> @@ -347,6 +347,12 @@ static void sugov_update_shared(struct update_util_data
> *hook, u64 time,
>
> sg_cpu->util = util;
> sg_cpu->max = max;
> +
> + /* CPU is entering IDLE, reset flags without triggering an update */
> + if (unlikely(flags & SCHED_CPUFREQ_IDLE)) {
> + sg_cpu->flags = 0;
> + goto done;
> + }
Looks good for now. I'm just thinking that we will happen for DL, as a
CPU that still "has" a sleeping task is not going to be really idle
until the 0-lag time. I guess we could move this at that point in time?
> sg_cpu->flags = flags;
>
> sugov_set_iowait_boost(sg_cpu, time, flags);
> @@ -361,6 +367,7 @@ static void sugov_update_shared(struct update_util_data
> *hook, u64 time,
> sugov_update_commit(sg_policy, time, next_f);
> }
>
> +done:
> raw_spin_unlock(&sg_policy->update_lock);
> }
>
> diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
> index d518664cce4f..6e8ae2aa7a13 100644
> --- a/kernel/sched/idle_task.c
> +++ b/kernel/sched/idle_task.c
> @@ -30,6 +30,10 @@ pick_next_task_idle(struct rq *rq, struct task_struct
> *prev, struct rq_flags *rf
> put_prev_task(rq, prev);
> update_idle_core(rq);
> schedstat_inc(rq->sched_goidle);
> +
> + /* kick cpufreq (see the comment in kernel/sched/sched.h). */
> + cpufreq_update_util(rq, SCHED_CPUFREQ_IDLE);
Don't know if it make things any cleaner, but you could add to the
comment that we don't actually trigger a frequency update with this
call.
Best,
Juri
