Re: [PATCH v3 01/14] sched/core: uclamp: extend sched_setattr to support utilization clamping

Hi,

Minor comments below.

On 06/08/18 17:39, Patrick Bellasi wrote:

[...]

+ *
+ * Task Utilization Attributes
+ * ===========================
+ *
+ * A subset of sched_attr attributes allows to specify the utilization which
+ * should be expected by a task. These attributes allows to inform the

                                                       ^
						     allow

+ * scheduler about the utilization boundaries within which is safe to schedule

Isn't all this more about providing hints than safety?

+ * the task. These utilization boundaries are valuable information to support
+ * scheduler decisions on both task placement and frequencies selection.
+ *
+ *  @sched_util_min	represents the minimum utilization
+ *  @sched_util_max	represents the maximum utilization
+ *
+ * Utilization is a value in the range [0..SCHED_CAPACITY_SCALE] which
+ * represents the percentage of CPU time used by a task when running at the
+ * maximum frequency on the highest capacity CPU of the system. Thus, for
+ * example, a 20% utilization task is a task running for 2ms every 10ms.
+ *
+ * A task with a min utilization value bigger then 0 is more likely to be
+ * scheduled on a CPU which can provide that bandwidth.
+ * A task with a max utilization value smaller then 1024 is more likely to be
+ * scheduled on a CPU which do not provide more then the required bandwidth.

Isn't s/bandwidth/capacity/ here, above, and in general where you use
the term "bandwidth" more appropriate? I wonder if overloading this term
(w.r.t. how is used with DEADLINE) might create confusion. In this case
we are not providing any sort of guarantees, it's a hint.

Best,

- Juri