Re: [PATCH v6 10/16] sched/core: Add uclamp_util_with()

Peter Zijlstra
2019-01-23T13:33:24Z

On Tue, Jan 15, 2019 at 10:15:07AM +0000, Patrick Bellasi wrote:
> +static __always_inline
> +unsigned int uclamp_util_with(struct rq *rq, unsigned int util,
> + struct task_struct *p)
> {
> unsigned int min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value);
> unsigned int max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
>
> + if (p) {
> + min_util = max(min_util, uclamp_effective_value(p, UCLAMP_MIN));
> + max_util = max(max_util, uclamp_effective_value(p, UCLAMP_MAX));
> + }
> +

Like I think you mentioned earlier; this doesn't look right at all.

Should that not be something like:

lo = READ_ONCE(rq->uclamp[UCLAMP_MIN].value);
hi = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);

min_util = clamp(uclamp_effective(p, UCLAMP_MIN), lo, hi);
max_util = clamp(uclamp_effective(p, UCLAMP_MAX), lo, hi);