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-rw-r--r--include/linux/sched.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5485f411e8e1..1113dd4706ae 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -587,6 +587,7 @@ struct sched_dl_entity {
* @value: clamp value "assigned" to a se
* @bucket_id: bucket index corresponding to the "assigned" value
* @active: the se is currently refcounted in a rq's bucket
+ * @user_defined: the requested clamp value comes from user-space
*
* The bucket_id is the index of the clamp bucket matching the clamp value
* which is pre-computed and stored to avoid expensive integer divisions from
@@ -596,11 +597,19 @@ struct sched_dl_entity {
* which can be different from the clamp value "requested" from user-space.
* This allows to know a task is refcounted in the rq's bucket corresponding
* to the "effective" bucket_id.
+ *
+ * The user_defined bit is set whenever a task has got a task-specific clamp
+ * value requested from userspace, i.e. the system defaults apply to this task
+ * just as a restriction. This allows to relax default clamps when a less
+ * restrictive task-specific value has been requested, thus allowing to
+ * implement a "nice" semantic. For example, a task running with a 20%
+ * default boost can still drop its own boosting to 0%.
*/
struct uclamp_se {
unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
unsigned int active : 1;
+ unsigned int user_defined : 1;
};
#endif /* CONFIG_UCLAMP_TASK */