On Mon, Aug 01, 2016 at 01:37:23AM +0200, Rafael J. Wysocki wrote:
...
> For this purpose, define a new cpufreq_update_util() flag
> UUF_IO and modify enqueue_task_fair() to pass that flag to
> cpufreq_update_util() in the in_iowait case. That generally
> requires cpufreq_update_util() to be called directly from there,
> because update_load_avg() is not likely to be invoked in that
> case.
I didn't follow why the cpufreq hook won't likely be called if
in_iowait is set? AFAICS update_load_avg() gets called in the second loop
and calls update_cfs_rq_load_avg (triggers the hook).
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> ---
> include/linux/sched.h | 1 +
> kernel/sched/fair.c | 8 ++++++++
> 2 files changed, 9 insertions(+)
>
> Index: linux-pm/kernel/sched/fair.c
> ===================================================================
> --- linux-pm.orig/kernel/sched/fair.c
> +++ linux-pm/kernel/sched/fair.c
> @@ -4459,6 +4459,14 @@ enqueue_task_fair(struct rq *rq, struct
> struct cfs_rq *cfs_rq;
> struct sched_entity *se = &p->se;
>
> + /*
> + * If in_iowait is set, it is likely that the loops below will not
> + * trigger any cpufreq utilization updates, so do it here explicitly
> + * with the IO flag passed.
> + */
> + if (p->in_iowait)
> + cpufreq_update_util(rq, UUF_IO);
> +
> for_each_sched_entity(se) {
> if (se->on_rq)
> break;
> Index: linux-pm/include/linux/sched.h
> ===================================================================
> --- linux-pm.orig/include/linux/sched.h
> +++ linux-pm/include/linux/sched.h
> @@ -3376,6 +3376,7 @@ static inline unsigned long rlimit_max(u
> }
>
> #define UUF_RT 0x01
> +#define UUF_IO 0x02
>
> #ifdef CONFIG_CPU_FREQ
> struct update_util_data {
thanks,
Steve
