Re: [PATCH v4 02/16] sched/core: uclamp: map TASK's clamp values into CPU's clamp groups

Patrick Bellasi
2018-09-14T08:47:13Z

On 13-Sep 21:20, Peter Zijlstra wrote:
> On Wed, Sep 12, 2018 at 06:42:09PM +0100, Patrick Bellasi wrote:
> > On 12-Sep 18:24, Peter Zijlstra wrote:
> > > On Tue, Aug 28, 2018 at 02:53:10PM +0100, Patrick Bellasi wrote:
>
> > > > {
> > > > + int group_id[UCLAMP_CNT] = { UCLAMP_NOT_VALID };
> > > > + int lower_bound, upper_bound;
> > > > + struct uclamp_se *uc_se;
> > > > + int result = 0;
> > >
> > > I think the thing would become much more readable if you set
> > > lower/upper_bound right here.
>
> > Actually it could also make sense to have them before the mutex ;)
>
> Indeed.
>
> + upper_bound = (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX)
> + ? attr->sched_util_max
> + : p->uclamp[UCLAMP_MAX].value;
> +
> + if (upper_bound == UCLAMP_NOT_VALID)
> + upper_bound = SCHED_CAPACITY_SCALE;
> + if (attr->sched_util_min > upper_bound) {
> + result = -EINVAL;
> + goto done;
> + }
> +
> + result = uclamp_group_find(UCLAMP_MIN, attr->sched_util_min);
> + if (result == -ENOSPC) {
> + pr_err(UCLAMP_ENOSPC_FMT, "MIN");
> + goto done;
> + }
> + group_id[UCLAMP_MIN] = result;
> + }
> + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) {
> + lower_bound = (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN)
> + ? attr->sched_util_min
> + : p->uclamp[UCLAMP_MIN].value;
> +
> + if (lower_bound == UCLAMP_NOT_VALID)
> + lower_bound = 0;
> + if (attr->sched_util_max < lower_bound ||
> + attr->sched_util_max > SCHED_CAPACITY_SCALE) {
> + result = -EINVAL;
> + goto done;
> + }
>
> That would end up soething like:
>
> unsigned int lower_bound = p->uclamp[UCLAMP_MIN].value;
> unsigned int upper_bound = p->uclamp[UCLAMP_MAX].value;
>
> if (sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN)
> lower_bound = attr->sched_util_min;
>
> if (sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX)
> upper_bound = attr->sched_util_max;
>
> if (lower_bound > upper_bound ||
> upper_bound > SCHED_CAPACITY_MAX)
> return -EINVAL;
>
> mutex_lock(...);

Yes... much cleaner, thanks.

--
#include <best/regards.h>

Patrick Bellasi