sched: wakeup granularity increase
increase wakeup granularity - we were overscheduling a bit.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 45c7493..a60b1da 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -74,7 +74,7 @@
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*/
-const_debug unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
+const_debug unsigned int sysctl_sched_wakeup_granularity = 2000000UL;
unsigned int sysctl_sched_runtime_limit __read_mostly;
@@ -582,7 +582,7 @@
* Preempt the current task with a newly woken task if needed:
*/
static void
-__check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *curr)
+check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
unsigned long ideal_runtime, delta_exec;
@@ -646,8 +646,6 @@
static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
- struct sched_entity *next;
-
/*
* Dequeue and enqueue the task to update its
* position within the tree:
@@ -655,14 +653,8 @@
dequeue_entity(cfs_rq, curr, 0);
enqueue_entity(cfs_rq, curr, 0);
- /*
- * Reschedule if another task tops the current one.
- */
- next = __pick_next_entity(cfs_rq);
- if (next == curr)
- return;
-
- __check_preempt_curr_fair(cfs_rq, curr);
+ if (cfs_rq->nr_running > 1)
+ check_preempt_tick(cfs_rq, curr);
}
/**************************************************
@@ -852,7 +844,7 @@
/*
* Preempt the current task with a newly woken task if needed:
*/
-static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p)
+static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
{
struct task_struct *curr = rq->curr;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
@@ -863,9 +855,12 @@
resched_task(curr);
return;
}
+ if (is_same_group(curr, p)) {
+ s64 delta = curr->se.vruntime - p->se.vruntime;
- if (is_same_group(curr, p))
- __check_preempt_curr_fair(cfs_rq, &curr->se);
+ if (delta > (s64)sysctl_sched_wakeup_granularity)
+ resched_task(curr);
+ }
}
static struct task_struct *pick_next_task_fair(struct rq *rq)
@@ -1095,7 +1090,7 @@
.dequeue_task = dequeue_task_fair,
.yield_task = yield_task_fair,
- .check_preempt_curr = check_preempt_curr_fair,
+ .check_preempt_curr = check_preempt_wakeup,
.pick_next_task = pick_next_task_fair,
.put_prev_task = put_prev_task_fair,
