| Date | Tue, 22 Jan 2019 16:21:32 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v6 08/16] sched/cpufreq: uclamp: Add utilization clamping for FAIR tasks |
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On Tue, Jan 15, 2019 at 10:15:05AM +0000, Patrick Bellasi wrote: > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -218,8 +218,15 @@ unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs, > * CFS tasks and we use the same metric to track the effective > * utilization (PELT windows are synchronized) we can directly add them > * to obtain the CPU's actual utilization. > + * > + * CFS utilization can be boosted or capped, depending on utilization > + * clamp constraints requested by currently RUNNABLE tasks. > + * When there are no CFS RUNNABLE tasks, clamps are released and > + * frequency will be gracefully reduced with the utilization decay. > */ > - util = util_cfs; > + util = (type == ENERGY_UTIL) > + ? util_cfs > + : uclamp_util(rq, util_cfs);
That's pretty horrible; what's wrong with:
util = util_cfs; if (type == FREQUENCY_UTIL) util = uclamp_util(rq, util);
That should generate the same code, but is (IMO) far easier to read.
> util += cpu_util_rt(rq); > > dl_util = cpu_util_dl(rq);
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