lkml.org 
[lkml]   [2021]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 2/2] sched/uclamp: Fix iowait boost escaping uclamp restriction
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
>

\
 
 \ /
  Last update: 2021-12-17 16:57    [W:0.150 / U:3.308 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site