On Fri, Jan 31, 2020 at 05:30:46PM +0000, Lukasz Luba wrote: > > > > > |-----------------------------------------------|--------------- > > > | performance | SchedUtil | SchedUtil | performance > > > | governor | governor | governor | governor > > > | | w/o EAS | w/ EAS | > > > ----------------|---------------|---------------|---------------|--------------- > > > hackbench w/ PL | 12.7s | 11.7s | 12.0s | 13.0s - 12.2s > > > hackbench w/o PL| 9.2s | 8.1s | 8.2s | 9.2s - 8.4s > > > > Why does the performance different before and after this patch? > > Probably due to better locality and cache utilization. I can see that > there is ~700k context switches vs ~450k and ~160k migrations vs ~50k. > If you need to communicate two threads in different clusters, it will go > through CCI. Mhmm... I was not specific - I mean, "performance governor". All this you mentioned should not differ between performance governor before and after. However once you have 12.7, then 13.0 - 12.2. Unless multi-core scheduler affects it... but then these numbers here are not showing only this change, but also the SCHED_MC effect. In such case each of commits should be coming with their own numbers. > As mentioned in response to patch 1/3. The fist patch would create MC > domain, something different than Energy Model or EAS. The decisions in > the scheduler would be different. > > I can merge 1/3 and 3/3 if you like, though. I understand now that their independent. Still, they are part of one goal to tune the scheduler for Exynos platform. Splitting these looks too much, like enabling multiple drivers one after another. However if you provide numbers for each of cases (before patches, multi core scheduler, energy model with DTS), then I see benefit of splitting it. Each commit would have its own rationale. I am not sure if it is worth such investigation - that's just defconfig... distros might ignore it anyway. Best regards, Krzysztof
