Re: [Resend][PATCH 1/3] cpufreq / sched: SCHED_CPUFREQ_IOWAIT flag to indicate iowait condition

From: Peter Zijlstra
Date: Tue Sep 13 2016 - 03:34:55 EST

On Fri, Sep 09, 2016 at 11:59:33PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Testing indicates that it is possible to improve performace
> significantly without increasing energy consumption too much by
> teaching cpufreq governors to bump up the CPU performance level if
> the in_iowait flag is set for the task in enqueue_task_fair().
> For this purpose, define a new cpufreq_update_util() flag
> SCHED_CPUFREQ_IOWAIT 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() may not be invoked in that case.
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Looks-good-to: Steve Muckle <smuckle@xxxxxxxxxx>

Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>