Re: [PATCH] cpufreq: schedutil: govern how frequently we change frequency with rate_limit

From: Peter Zijlstra
Date: Thu Feb 16 2017 - 07:36:27 EST

On Thu, Feb 16, 2017 at 03:42:10PM +0530, Viresh Kumar wrote:
> But when I discussed this with Vincent, he suggested that it may not be required
> at all as the scheduler (with the helped of "decayed") doesn't call into
> schedutil too often, i.e. at least 1 ms. And if the CPUs are stable enough (i.e.
> no interruptions to the running task), we wouldn't reevaluate before the next
> tick.

There are still the attach/detach callers to cfs_rq_util_change() that
kick in for fork/exit and migration.

But yes, barring those we shouldn't end up calling it at silly rates.