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

From: Patrick Bellasi
Date: Wed Mar 13 2019 - 12:16:54 EST


On 13-Mar 15:12, Peter Zijlstra wrote:
> On Fri, Feb 08, 2019 at 10:05:41AM +0000, Patrick Bellasi wrote:
> > +static inline void uclamp_idle_reset(struct rq *rq, unsigned int clamp_id,
> > + unsigned int clamp_value)
> > +{
> > + /* Reset max-clamp retention only on idle exit */
> > + if (!(rq->uclamp_flags & UCLAMP_FLAG_IDLE))
> > + return;
> > +
> > + WRITE_ONCE(rq->uclamp[clamp_id].value, clamp_value);
> > +
> > + /*
> > + * This function is called for both UCLAMP_MIN (before) and UCLAMP_MAX
> > + * (after). The idle flag is reset only the second time, when we know
> > + * that UCLAMP_MIN has been already updated.
>
> Why do we care? That is, what is this comment trying to tell us.

Right, the code is clear enough, I'll remove this comment.

>
> > + */
> > + if (clamp_id == UCLAMP_MAX)
> > + rq->uclamp_flags &= ~UCLAMP_FLAG_IDLE;
> > +}

--
#include <best/regards.h>

Patrick Bellasi