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Wysocki" , Ingo Molnar , Thomas Gleixner , Vincent Guittot , Morten Rasmussen , dietmar.eggemann@arm.com, patrick.bellasi@matbug.net, lenb@kernel.org, linux-kernel@vger.kernel.org, valentin.schneider@arm.com, ionela.voinescu@arm.com, qperret@google.com, viresh.kumar@linaro.org Subject: Re: [RFC] Documentation/scheduler/schedutil.txt Message-ID: <20201202165828.GC2414@hirez.programming.kicks-ass.net> References: <20201120075527.GB2414@hirez.programming.kicks-ass.net> <20201202141835.GY3306@suse.de> <20201202155452.GK3021@hirez.programming.kicks-ass.net> <20201202164531.GA3306@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201202164531.GA3306@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 02, 2020 at 04:45:31PM +0000, Mel Gorman wrote: > > > It's less obvious what the consequence is unless the reader manages to > > > tie the IO-wait comment in "Schedutil / DVFS" to this section. > > > > I'm not entirely sure I follow. The purpose of UTIL_EST is to avoid > > ramp-up issues and isn't related to IO-wait boosting. > > > > I mixed up the example. Historically io-wait boosting was one way of > avoiding DVFS ramp-up issues but now that I reread it, it's best to leave > it general like you already have in your current version. So IO-wait boosting is an interesting case; as it captures something not present in the rest of the model, namely interaction. There's also that series of patches that does the cpu/gpu interaction thing. It would be worth expanding on it, but I didn't have it in me to dig through the archives to get a coherent description of the current state of things. Something left todo later...