| Date | Tue, 7 Aug 2018 14:54:04 +0100 | From | Quentin Perret <> | Subject | Re: [PATCH v3 06/14] sched/cpufreq: uclamp: add utilization clamping for RT tasks |
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Hi Patrick,
On Monday 06 Aug 2018 at 17:39:38 (+0100), Patrick Bellasi wrote: > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c > index a7affc729c25..bb25ef66c2d3 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -200,6 +200,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, > static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) > { > struct rq *rq = cpu_rq(sg_cpu->cpu); > + unsigned long util_cfs, util_rt; > unsigned long util, irq, max; > > sg_cpu->max = max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
IIUC, not far below this you should still have something like:
if (rt_rq_is_runnable(&rq->rt)) return max;
So you won't reach the actual clamping code at the end of the function when a RT task is runnable no?
Also, I always had the feeling that the default for RT should be util_min == 1024, and then users could decide to lower the bar if they want to. For the specific case of RT, that feels more natural than applying a max util clamp IMO. What do you think ?
Thanks, Quentin
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