[RFC v4 3/8] sched/core: Update turbo_sched count only when required

[Parth Shah]

Use the get/put methods to add/remove the use of TurboSched support, such
that the feature is turned on only if there is atleast one jitter task.

Signed-off-by: Parth Shah <pa...@linux.ibm.com>
---
 kernel/sched/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ee5980b4e150..60340fa18abb 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3141,6 +3141,9 @@ static struct rq *finish_task_switch(struct task_struct 
*prev)
                mmdrop(mm);
        }
        if (unlikely(prev_state == TASK_DEAD)) {
+               if (unlikely(prev->flags & PF_CAN_BE_PACKED))
+                       turbo_sched_put();
+
                if (prev->sched_class->task_dead)
                        prev->sched_class->task_dead(prev);
 
@@ -4793,6 +4796,10 @@ static int __sched_setscheduler(struct task_struct *p,
 
        prev_class = p->sched_class;
 
+       /* Refcount tasks classified as jitter task */
+       if (task_packing_flag != (p->flags & PF_CAN_BE_PACKED))
+               (task_packing_flag) ? turbo_sched_get() : turbo_sched_put();
+
        __setscheduler(rq, p, attr, pi);
        __setscheduler_uclamp(p, attr);
 
-- 
2.17.1