From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juri Lelli Subject: Re: [PATCH RFC 4/8] sched/cpufreq_schedutil: split utilization signals Date: Wed, 24 May 2017 10:01:02 +0100 Message-ID: <20170524090102.wjljvyxw5acbdwfd@e106622-lin> References: <20170523085351.18586-1-juri.lelli@arm.com> <20170523085351.18586-5-juri.lelli@arm.com> <20170523192927.ri2n72hrobghlros@hirez.programming.kicks-ass.net> <1941953.5pVr1esCdP@aspire.rjw.lan> <20170524070107.xq7tmjxqg6afsrss@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170524070107.xq7tmjxqg6afsrss@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra Cc: "Rafael J. Wysocki" , mingo@redhat.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, tglx@linutronix.de, vincent.guittot@linaro.org, rostedt@goodmis.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, tkjos@android.com, joelaf@google.com, andresoportus@google.com, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, patrick.bellasi@arm.com, Ingo Molnar List-Id: linux-pm@vger.kernel.org Hi, On 24/05/17 09:01, Peter Zijlstra wrote: > 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.. Sure, I can add that in next version. Thanks, - Juri