Messages in this thread | | | Date | Tue, 22 Jan 2019 12:13:22 +0000 | From | Quentin Perret <> | Subject | Re: [PATCH v6 11/16] sched/fair: Add uclamp support to energy_compute() |
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On Tuesday 15 Jan 2019 at 10:15:08 (+0000), Patrick Bellasi wrote: > The Energy Aware Scheduler (AES) estimates the energy impact of waking
s/AES/EAS :-)
[...] > + for_each_cpu_and(cpu, pd_mask, cpu_online_mask) { > + cfs_util = cpu_util_next(cpu, p, dst_cpu); > + > + /* > + * Busy time computation: utilization clamping is not > + * required since the ratio (sum_util / cpu_capacity) > + * is already enough to scale the EM reported power > + * consumption at the (eventually clamped) cpu_capacity. > + */
Right.
> + sum_util += schedutil_cpu_util(cpu, cfs_util, cpu_cap, > + ENERGY_UTIL, NULL); > + > + /* > + * Performance domain frequency: utilization clamping > + * must be considered since it affects the selection > + * of the performance domain frequency. > + */
So that actually affects the way we deal with RT I think. I assume the idea is to say if you don't want to reflect the RT-go-to-max-freq thing in EAS (which is what we do now) you should set the min cap for RT to 0. Is that correct ?
I'm fine with this conceptually but maybe the specific case of RT should be mentioned somewhere in the commit message or so ? I think it's important to say that clearly since this patch changes the default behaviour.
> + cpu_util = schedutil_cpu_util(cpu, cfs_util, cpu_cap, > + FREQUENCY_UTIL, > + cpu == dst_cpu ? p : NULL); > + max_util = max(max_util, cpu_util); > } > > energy += em_pd_energy(pd->em_pd, max_util, sum_util);
Thanks, Quentin
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