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sched: Provide p->on_rq

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Provide a generic p->on_rq because the p->se.on_rq semantics are
unfavourable for lockless wakeups but needed for sched_fair.

In particular, p->on_rq is only cleared when we actually dequeue the
task in schedule() and not on any random dequeue as done by things
like __migrate_task() and __sched_setscheduler().

This also allows us to remove p->se usage from !sched_fair code.

Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
This commit is contained in:
Peter Zijlstra
2011-04-05 17:23:44 +02:00
committed by Ingo Molnar
parent d7c01d27ab
commit fd2f4419b4
5 changed files with 31 additions and 28 deletions
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16
kernel/sched_rt.c
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@ -1136,7 +1136,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
* The previous task needs to be made eligible for pushing
* if it is still active
*/
if (p->se.on_rq && p->rt.nr_cpus_allowed > 1)
if (on_rt_rq(&p->rt) && p->rt.nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
}
@ -1287,7 +1287,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
!cpumask_test_cpu(lowest_rq->cpu,
&task->cpus_allowed) ||
task_running(rq, task) ||
!task->se.on_rq)) {
!task->on_rq)) {
raw_spin_unlock(&lowest_rq->lock);
lowest_rq = NULL;
@ -1321,7 +1321,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq)
BUG_ON(task_current(rq, p));
BUG_ON(p->rt.nr_cpus_allowed <= 1);
BUG_ON(!p->se.on_rq);
BUG_ON(!p->on_rq);
BUG_ON(!rt_task(p));
return p;
@ -1467,7 +1467,7 @@ static int pull_rt_task(struct rq *this_rq)
*/
if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
WARN_ON(p == src_rq->curr);
WARN_ON(!p->se.on_rq);
WARN_ON(!p->on_rq);
/*
* There's a chance that p is higher in priority
@ -1538,7 +1538,7 @@ static void set_cpus_allowed_rt(struct task_struct *p,
* Update the migration status of the RQ if we have an RT task
* which is running AND changing its weight value.
*/
if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) {
if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) {
struct rq *rq = task_rq(p);
if (!task_current(rq, p)) {
@ -1608,7 +1608,7 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
* we may need to handle the pulling of RT tasks
* now.
*/
if (p->se.on_rq && !rq->rt.rt_nr_running)
if (p->on_rq && !rq->rt.rt_nr_running)
pull_rt_task(rq);
}
@ -1638,7 +1638,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
* If that current running task is also an RT task
* then see if we can move to another run queue.
*/
if (p->se.on_rq && rq->curr != p) {
if (p->on_rq && rq->curr != p) {
#ifdef CONFIG_SMP
if (rq->rt.overloaded && push_rt_task(rq) &&
/* Don't resched if we changed runqueues */
@ -1657,7 +1657,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
static void
prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
{
if (!p->se.on_rq)
if (!p->on_rq)
return;
if (rq->curr == p) {