Messages in this thread | | | Subject | Re: [RFCv5 PATCH 40/46] sched/cpufreq_sched: compute freq_new based on capacity_orig_of() | From | Steve Muckle <> | Date | Tue, 13 Oct 2015 12:47:53 -0700 |
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On 08/17/2015 05:19 AM, Juri Lelli wrote: >> Nah, just maybe: (capacity << SCHED_CAPACITY_SHIFT) / capacity_orig_of() >> > such that you don't have to export that knowledge to this thing. >> > > Oh, right. I guess we can just go with something like: > > req_cap = get_cpu_usage(cpu) * capacity_margin / capacity_orig_of(cpu); > > on fair.c side and switch back to > > freq_new = capacity * policy->max >> SCHED_CAPACITY_SHIFT; > > on cpufreq_sched.c side. That saves us exporting capacity_orig_of().
Another good reason to make this change - I believe the current code will not support a cpufreq policy covering CPUs of different types (such as a b.L system in a single frequency domain).
The max requested capacity is calculated using the absolute/global capacity values requested from each CPU. A small CPU needing a higher OPP may get ignored because of a request from a big CPU for a lower OPP, because the big CPU @ lower OPP shows up as the max capacity request.
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