Messages in this thread | | | Date | Wed, 24 May 2017 09:01:07 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH RFC 4/8] sched/cpufreq_schedutil: split utilization signals |
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On Wed, May 24, 2017 at 01:30:36AM +0200, Rafael J. Wysocki wrote: > On Tuesday, May 23, 2017 09:29:27 PM Peter Zijlstra wrote: > > On Tue, May 23, 2017 at 09:53:47AM +0100, Juri Lelli wrote: > > > To be able to treat utilization signals of different scheduling classes > > > in different ways (e.g., CFS signal might be stale while DEADLINE signal > > > is never stale by design) we need to split sugov_cpu::util signal in two: > > > util_cfs and util_dl. > > > > > > This patch does that by also changing sugov_get_util() parameter list. > > > After this change aggregation of the different signals has to be performed > > > by sugov_get_util() users (so that they can decide what to do with the > > > different signals). > > > > So what I don't see this patch doing; and I don't remember if cpufreq is > > ready for this at all, is set the util_dl as min/guaranteed freq and > > util_cfs+util_dl as requested freq. > > I'm totally unsure what you mean here.
I was thinking of the CPPC/HWP stuff, where you can set different frequencies with different levels of guarantees.
We'd want to set util_dl as the minimum (guaranteed) performance, and util_dl + util_cfs as the desired performance level.
> cpufreq doesn't have a "guaranteed frequency" concept of any sort right now.
I was afraid of that ;-) I think we want a comment in the code stating that this is the desired goal though. Then once cpufreq is ready to deal with it we can change it..
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