Re: [PATCH 5/8] sched/cpufreq: pass sched class into cpufreq_update_util

[Peter Zijlstra]

On Wed, Mar 16, 2016 at 09:29:59AM +0100, Vincent Guittot wrote:
> I wonder if it's really worth passing per sched_class request to
> sched_util ? sched_util is about selecting a frequency based on the
> utilization of the CPU, it only needs a value that reflect the whole
> utilization. Can't we sum  (or whatever the formula we want to apply)
> utilizations before calling cpufreq_update_util

So I've thought the same; but I'm conflicted, its a shame to compute
anything if the call then doesn't do anything with it.

And keeping a structure of all the various numbers to pass in also has
cost of yet another cacheline to touch.