Re: [PATCH v7 02/15] sched/core: uclamp: Enforce last task UCLAMP_MAX

Patrick Bellasi
2019-03-13T16:20:51Z

On 13-Mar 15:10, Peter Zijlstra wrote:
> On Fri, Feb 08, 2019 at 10:05:41AM +0000, Patrick Bellasi wrote:
> > +uclamp_idle_value(struct rq *rq, unsigned int clamp_id, unsigned int clamp_value)
> > +{
> > + /*
> > + * Avoid blocked utilization pushing up the frequency when we go
> > + * idle (which drops the max-clamp) by retaining the last known
> > + * max-clamp.
> > + */
> > + if (clamp_id == UCLAMP_MAX) {
> > + rq->uclamp_flags |= UCLAMP_FLAG_IDLE;
> > + return clamp_value;
> > + }
> > +
> > + return uclamp_none(UCLAMP_MIN);
>
> That's a very complicated way or writing: return 0, right?

In my mind it's just a simple way to hardcode values in just one place.

In the current implementation uclamp_none(UCLAMP_MIN) is 0 and the
compiler is not in trubles to inline a 0 there.

Is it really so disgusting ?

--
#include <best/regards.h>

Patrick Bellasi