===================
```
i=8;
./turbo_bench -t 30 -h $i -n $((2*i)) -j
```
This spawns 2*i total threads: of which i-CPU bound and i-jitter threads.
Signed-off-by: Parth Shah <parth@linux.ibm.com>
---
include/linux/sched.h | 6 ++++++
kernel/sched/core.c | 9 +++++++++
2 files changed, 15 insertions(+)
@@ -696,6 +696,12 @@ struct task_struct {
struct uclamp_se uclamp_req[UCLAMP_CNT];
/* Effective clamp values used for a scheduling entity */
struct uclamp_se uclamp[UCLAMP_CNT];
+ /*
+ * Tag the task as jitter.
+ * 0 = regular. Follows regular CFS policy for task placement.
+ * 1 = Jitter tasks. Should be packed to reduce active core count.
+ */
+ unsigned int is_jitter;
#endif
#ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -1189,6 +1189,15 @@ static void __setscheduler_uclamp(struct task_struct *p,
if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) {
uclamp_se_set(&p->uclamp_req[UCLAMP_MAX],
attr->sched_util_max, true);
+
+ /*
+ * Set task to jitter class if Max util is clamped to the least
+ * possible value
+ */
+ if (p->uclamp_req[UCLAMP_MAX].bucket_id == 0 && !p->is_jitter)
+ p->is_jitter = 1;
+ else if (p->is_jitter)
+ p->is_jitter = 0;
}
}