Re: [PATCH v4 08/16] sched/core: uclamp: propagate parent clamps

Patrick Bellasi
2018-09-12T12:51:42Z

On 08-Sep 20:02, Suren Baghdasaryan wrote:
> On Tue, Aug 28, 2018 at 6:53 AM, Patrick Bellasi
> <patrick.bellasi@arm.com> wrote:

[...]

> > + cpu.util.min.effective
> > + A read-only single value file which exists on non-root cgroups and
> > + reports minimum utilization clamp value currently enforced on a task
> > + group.
> > +
> > + The actual minimum utilization in the range [0, 1023].
> > +
> > + This value can be lower then cpu.util.min in case a parent cgroup
> > + is enforcing a more restrictive clamping on minimum utilization.
>
> IMHO if cpu.util.min=0 means "no restrictions" on UCLAMP_MIN then
> calling parent's lower cpu.util.min value "more restrictive clamping"
> is confusing. I would suggest to rephrase this to smth like "...in
> case a parent cgroup requires lower cpu.util.min clamping."

Right, it's slightly confusing... still I would like to call out that
a parent group can enforce something on its children. What about:

"... a parent cgroup allows only smaller minimum utilization values."

Is that less confusing ?

Otherwise I think your proposal could work too.

[...]

> > #ifdef CONFIG_UCLAMP_TASK_GROUP
> > +/**
> > + * cpu_util_update_hier: propagete effective clamp down the hierarchy
>
> typo: propagate

+1

[...]

> > + * Skip the whole subtrees if the current effective clamp is
> > + * alredy matching the TG's clamp value.
>
> typo: already

+1

Cheers,
Patrick

--
#include <best/regards.h>

Patrick Bellasi