On Mon, Oct 29, 2018 at 06:33:02PM +0000, Patrick Bellasi wrote: > The number of clamp groups configured at compile time defines the range > of utilization clamp values tracked by each CPU clamp group. > For example, with the default configuration: > CONFIG_UCLAMP_GROUPS_COUNT 5 > we will have 5 clamp groups tracking 20% utilization each. In this case, > a task with util_min=25% will have group_id=1.
OK I suppose; but should we not do a wholesale s/group/bucket/ at this point? We should probably raise the minimum number of buckets from 1 though :-) > +/* > + * uclamp_group_value: get the "group value" for a given "clamp value" > + * @value: the utiliation "clamp value" to translate > + * > + * The number of clamp group, which is defined at compile time, allows to > + * track a finite number of different clamp values. Thus clamp values are > + * grouped into bins each one representing a different "group value". > + * This method returns the "group value" corresponding to the specified > + * "clamp value". > + */ > +static inline unsigned int uclamp_group_value(unsigned int clamp_value) > +{ > +#define UCLAMP_GROUP_DELTA (SCHED_CAPACITY_SCALE / > CONFIG_UCLAMP_GROUPS_COUNT) > +#define UCLAMP_GROUP_UPPER (UCLAMP_GROUP_DELTA * CONFIG_UCLAMP_GROUPS_COUNT) > + > + if (clamp_value >= UCLAMP_GROUP_UPPER) > + return SCHED_CAPACITY_SCALE; > + > + return UCLAMP_GROUP_DELTA * (clamp_value / UCLAMP_GROUP_DELTA); > +} Can't we further simplify; I mean, at this point all we really need to know is the rq's highest group_id that is in use. We don't need to actually track the value anymore.