Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Fri, 17 Dec 2021 16:56:33 +0100 | Subject | Re: [PATCH 2/2] sched/uclamp: Fix iowait boost escaping uclamp restriction |
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On Thu, Dec 16, 2021 at 11:53 PM Qais Yousef <qais.yousef@arm.com> wrote: > > iowait_boost signal is applied independently of util and doesn't take > into account uclamp settings of the rq. An io heavy task that is capped > by uclamp_max could still request higher frequency because > sugov_iowait_apply() doesn't clamp the boost via uclamp_rq_util_with() > like effective_cpu_util() does. > > Make sure that iowait_boost honours uclamp requests by calling > uclamp_rq_util_with() when applying the boost. > > Fixes: 982d9cdc22c9 ("sched/cpufreq, sched/uclamp: Add clamps for FAIR and RT tasks") > Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> --- > kernel/sched/cpufreq_schedutil.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c > index 48327970552a..93dcea233c65 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -289,6 +289,7 @@ static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time) > * into the same scale so we can compare. > */ > boost = (sg_cpu->iowait_boost * sg_cpu->max) >> SCHED_CAPACITY_SHIFT; > + boost = uclamp_rq_util_with(cpu_rq(sg_cpu->cpu), boost, NULL); > if (sg_cpu->util < boost) > sg_cpu->util = boost; > } > -- > 2.25.1 >
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