Messages in this thread |  | | Date | Fri, 13 Apr 2018 11:46:15 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/7] sched/core: uclamp: add CPU clamp groups accounting |
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On Mon, Apr 09, 2018 at 05:56:09PM +0100, Patrick Bellasi wrote: > +static inline void uclamp_cpu_get(struct task_struct *p, int cpu, int clamp_id) > +{ > + struct uclamp_cpu *uc_cpu = &cpu_rq(cpu)->uclamp[clamp_id]; > + int clamp_value; > + int group_id; > + > + /* Get task's specific clamp value */ > + clamp_value = p->uclamp[clamp_id].value; > + group_id = p->uclamp[clamp_id].group_id; > + > + /* No task specific clamp values: nothing to do */ > + if (group_id == UCLAMP_NONE) > + return; > + > + /* Increment the current group_id */
That I think qualifies being called a bad comment.
> + uc_cpu->group[group_id].tasks += 1; > + > + /* Mark task as enqueued for this clamp index */ > + p->uclamp_group_id[clamp_id] = group_id;
Why exactly do we need this? we got group_id from @p in the first place.
I suspect this is because when we update p->uclamp[], we don't update this active value (when needed), is that worth it?
> + /* > + * If this is the new max utilization clamp value, then we can update > + * straight away the CPU clamp value. Otherwise, the current CPU clamp > + * value is still valid and we are done. > + */ > + if (uc_cpu->value < clamp_value) > + uc_cpu->value = clamp_value; > +}
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