sched: add set_curr_task() calls

p->sched_class->set_curr_task() has to be called before
activate_task()/enqueue_task() in rt_mutex_setprio(),
sched_setschedule() and sched_move_task() in order to set up
'cfs_rq->curr'. The logic of enqueueing depends on whether a task to be
inserted is 'current' or not.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/sched.c b/kernel/sched.c
index b2688ce..6d18921 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3915,8 +3915,8 @@ EXPORT_SYMBOL(sleep_on_timeout);
  */
 void rt_mutex_setprio(struct task_struct *p, int prio)
 {
+       int oldprio, on_rq, running;
        unsigned long flags;
-       int oldprio, on_rq;
        struct rq *rq;
 
        BUG_ON(prio < 0 || prio > MAX_PRIO);
@@ -3926,9 +3926,10 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
 
        oldprio = p->prio;
        on_rq = p->se.on_rq;
+       running = task_running(rq, p);
        if (on_rq) {
                dequeue_task(rq, p, 0);
-               if (task_running(rq, p))
+               if (running)
                        p->sched_class->put_prev_task(rq, p);
        }
 
@@ -3940,16 +3941,17 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
        p->prio = prio;
 
        if (on_rq) {
+               if (running)
+                       p->sched_class->set_curr_task(rq);
                enqueue_task(rq, p, 0);
                /*
                 * Reschedule if we are currently running on this runqueue and
                 * our priority decreased, or if we are not currently running on
                 * this runqueue and our priority is higher than the current's
                 */
-               if (task_running(rq, p)) {
+               if (running) {
                        if (p->prio > oldprio)
                                resched_task(rq->curr);
-                       p->sched_class->set_curr_task(rq);
                } else {
                        check_preempt_curr(rq, p);
                }
@@ -4153,7 +4155,7 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
 int sched_setscheduler(struct task_struct *p, int policy,
                       struct sched_param *param)
 {
-       int retval, oldprio, oldpolicy = -1, on_rq;
+       int retval, oldprio, oldpolicy = -1, on_rq, running;
        unsigned long flags;
        struct rq *rq;
 
@@ -4235,24 +4237,26 @@ recheck:
        }
        update_rq_clock(rq);
        on_rq = p->se.on_rq;
+       running = task_running(rq, p);
        if (on_rq) {
                deactivate_task(rq, p, 0);
-               if (task_running(rq, p))
+               if (running)
                        p->sched_class->put_prev_task(rq, p);
        }
        oldprio = p->prio;
        __setscheduler(rq, p, policy, param->sched_priority);
        if (on_rq) {
+               if (running)
+                       p->sched_class->set_curr_task(rq);
                activate_task(rq, p, 0);
                /*
                 * Reschedule if we are currently running on this runqueue and
                 * our priority decreased, or if we are not currently running on
                 * this runqueue and our priority is higher than the current's
                 */
-               if (task_running(rq, p)) {
+               if (running) {
                        if (p->prio > oldprio)
                                resched_task(rq->curr);
-                       p->sched_class->set_curr_task(rq);
                } else {
                        check_preempt_curr(rq, p);
                }
@@ -6861,9 +6865,9 @@ static void sched_move_task(struct container_subsys *ss, struct container *cont,
        set_task_cfs_rq(tsk);
 
        if (on_rq) {
-               enqueue_task(rq, tsk, 0);
                if (unlikely(running))
                        tsk->sched_class->set_curr_task(rq);
+               enqueue_task(rq, tsk, 0);
        }
 
 done: