sched: Add enqueue/dequeue flags
In order to reduce the dependency on TASK_WAKING rework the enqueue
interface to support a proper flags field.
Replace the int wakeup, bool head arguments with an int flags argument
and create the following flags:
ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task,
ENQUEUE_WAKING - the enqueue has relative vruntime due to
having sched_class::task_waking() called,
ENQUEUE_HEAD - the waking task should be places on the head
of the priority queue (where appropriate).
For symmetry also convert sched_class::dequeue() to a flags scheme.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 14c8d2a..4a57e96d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1877,44 +1877,43 @@
*avg += diff >> 3;
}
-static void
-enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
+static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
update_rq_clock(rq);
sched_info_queued(p);
- p->sched_class->enqueue_task(rq, p, wakeup, head);
+ p->sched_class->enqueue_task(rq, p, flags);
p->se.on_rq = 1;
}
-static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
+static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
update_rq_clock(rq);
sched_info_dequeued(p);
- p->sched_class->dequeue_task(rq, p, sleep);
+ p->sched_class->dequeue_task(rq, p, flags);
p->se.on_rq = 0;
}
/*
* activate_task - move a task to the runqueue.
*/
-static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
+static void activate_task(struct rq *rq, struct task_struct *p, int flags)
{
if (task_contributes_to_load(p))
rq->nr_uninterruptible--;
- enqueue_task(rq, p, wakeup, false);
+ enqueue_task(rq, p, flags);
inc_nr_running(rq);
}
/*
* deactivate_task - remove a task from the runqueue.
*/
-static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
+static void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
{
if (task_contributes_to_load(p))
rq->nr_uninterruptible++;
- dequeue_task(rq, p, sleep);
+ dequeue_task(rq, p, flags);
dec_nr_running(rq);
}
@@ -2353,6 +2352,7 @@
{
int cpu, orig_cpu, this_cpu, success = 0;
unsigned long flags;
+ unsigned long en_flags = ENQUEUE_WAKEUP;
struct rq *rq;
this_cpu = get_cpu();
@@ -2386,8 +2386,10 @@
}
p->state = TASK_WAKING;
- if (p->sched_class->task_waking)
+ if (p->sched_class->task_waking) {
p->sched_class->task_waking(rq, p);
+ en_flags |= ENQUEUE_WAKING;
+ }
cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags);
if (cpu != orig_cpu)
@@ -2432,7 +2434,7 @@
schedstat_inc(p, se.statistics.nr_wakeups_local);
else
schedstat_inc(p, se.statistics.nr_wakeups_remote);
- activate_task(rq, p, 1);
+ activate_task(rq, p, en_flags);
success = 1;
out_running:
@@ -3623,7 +3625,7 @@
if (unlikely(signal_pending_state(prev->state, prev)))
prev->state = TASK_RUNNING;
else
- deactivate_task(rq, prev, 1);
+ deactivate_task(rq, prev, DEQUEUE_SLEEP);
switch_count = &prev->nvcsw;
}
@@ -4193,7 +4195,7 @@
if (running)
p->sched_class->set_curr_task(rq);
if (on_rq) {
- enqueue_task(rq, p, 0, oldprio < prio);
+ enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
check_class_changed(rq, p, prev_class, oldprio, running);
}
@@ -4236,7 +4238,7 @@
delta = p->prio - old_prio;
if (on_rq) {
- enqueue_task(rq, p, 0, false);
+ enqueue_task(rq, p, 0);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
@@ -8180,7 +8182,7 @@
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
if (on_rq)
- enqueue_task(rq, tsk, 0, false);
+ enqueue_task(rq, tsk, 0);
task_rq_unlock(rq, &flags);
}