Thread (3 messages) flat view 3 messages, 3 authors, 2018-11-07

Re: [PATCH v5 01/15] sched/core: uclamp: extend sched_setattr to support utilization clamping

From: Randy Dunlap <rdunlap@infradead.org>
Date: 2018-10-29 19:33:46
Also in: linux-pm, lkml

On 10/29/18 11:32 AM, Patrick Bellasi wrote:
quoted hunk ↗ jump to hunk
diff --git a/include/uapi/linux/sched/types.h b/include/uapi/linux/sched/types.h
index 10fbb8031930..fde7301ed28c 100644
--- a/include/uapi/linux/sched/types.h
+++ b/include/uapi/linux/sched/types.h
quoted hunk ↗ jump to hunk
@@ -53,6 +73,30 @@ struct sched_param {
  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
  * only user of this new interface. More information about the algorithm
  * available in the scheduling class file or in Documentation/.
+ *
+ * Task Utilization Attributes
+ * ===========================
+ *
+ * A subset of sched_attr attributes allows to specify the utilization which
+ * should be expected by a task. These attributes allow to inform the
+ * scheduler about the utilization boundaries within which it is expected to
+ * schedule the task. These boundaries are valuable hints 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
                                                 than
+ * scheduled on a CPU which has a capacity big enough to fit the specified
+ * minimum utilization value.
+ * A task with a max utilization value smaller then 1024 is more likely to be
+ * scheduled on a CPU which do not necessarily have more capacity then the
                               does                                  than
+ * specified max utilization value.
  */
 struct sched_attr {
 	__u32 size;

cheers.
-- 
~Randy
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