Re: [PATCH v4 03/16] sched/core: uclamp: add CPU's clamp groups accounting
From: Peter Zijlstra <peterz@infradead.org>
Date: 2018-09-13 19:12:31
Also in:
lkml
On Tue, Aug 28, 2018 at 02:53:11PM +0100, Patrick Bellasi wrote:
+static inline void uclamp_cpu_get_id(struct task_struct *p,
+ struct rq *rq, int clamp_id)
+{
+ struct uclamp_group *uc_grp;
+ struct uclamp_cpu *uc_cpu;
+ int clamp_value;
+ int group_id;
+
+ /* Every task must reference a clamp group */
+ group_id = p->uclamp[clamp_id].group_id;+}
+
+static inline void uclamp_cpu_put_id(struct task_struct *p,
+ struct rq *rq, int clamp_id)
+{
+ struct uclamp_group *uc_grp;
+ struct uclamp_cpu *uc_cpu;
+ unsigned int clamp_value;
+ int group_id;
+
+ /* New tasks don't have a previous clamp group */
+ group_id = p->uclamp[clamp_id].group_id;
+ if (group_id == UCLAMP_NOT_VALID)
+ return;*confused*, so on enqueue they must have a group_id, but then on dequeue they might no longer have?
+}
quoted hunk ↗ jump to hunk
@@ -1110,6 +1313,7 @@ static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) if (!(flags & ENQUEUE_RESTORE)) sched_info_queued(rq, p); + uclamp_cpu_get(rq, p); p->sched_class->enqueue_task(rq, p, flags); }@@ -1121,6 +1325,7 @@ static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags) if (!(flags & DEQUEUE_SAVE)) sched_info_dequeued(rq, p); + uclamp_cpu_put(rq, p); p->sched_class->dequeue_task(rq, p, flags); }
The ordering, is that right? We get while the task isn't enqueued yet, which would suggest we put when the task is dequeued.