5 files changed, 66 insertions, 34 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 8b718b59b09f..78fa75394011 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2057,14 +2057,14 @@ inline int task_curr(const struct task_struct *p)
 
 static inline void check_class_changed(struct rq *rq, struct task_struct *p,
                                        const struct sched_class *prev_class,
-                                       int oldprio, int running)
+                                       int oldprio)
 {
         if (prev_class != p->sched_class) {
                 if (prev_class->switched_from)
-                        prev_class->switched_from(rq, p, running);
-                p->sched_class->switched_to(rq, p, running);
-        } else
-                p->sched_class->prio_changed(rq, p, oldprio, running);
+                        prev_class->switched_from(rq, p);
+                p->sched_class->switched_to(rq, p);
+        } else if (oldprio != p->prio)
+                p->sched_class->prio_changed(rq, p, oldprio);
 }
 
 static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
@@ -2598,6 +2598,7 @@ static void __sched_fork(struct task_struct *p)
         p->se.sum_exec_runtime          = 0;
         p->se.prev_sum_exec_runtime     = 0;
         p->se.nr_migrations             = 0;
+        p->se.vruntime                  = 0;
 
 #ifdef CONFIG_SCHEDSTATS
         memset(&p->se.statistics, 0, sizeof(p->se.statistics));
@@ -4696,11 +4697,10 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
 
         if (running)
                 p->sched_class->set_curr_task(rq);
-        if (on_rq) {
+        if (on_rq)
                 enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
 
-                check_class_changed(rq, p, prev_class, oldprio, running);
-        }
+        check_class_changed(rq, p, prev_class, oldprio);
         task_rq_unlock(rq, &flags);
 }
 
@@ -5028,11 +5028,10 @@ recheck:
 
         if (running)
                 p->sched_class->set_curr_task(rq);
-        if (on_rq) {
+        if (on_rq)
                 activate_task(rq, p, 0);
 
-                check_class_changed(rq, p, prev_class, oldprio, running);
-        }
+        check_class_changed(rq, p, prev_class, oldprio);
         __task_rq_unlock(rq);
         raw_spin_unlock_irqrestore(&p->pi_lock, flags);
 
@@ -8237,6 +8236,8 @@ EXPORT_SYMBOL(__might_sleep);
 #ifdef CONFIG_MAGIC_SYSRQ
 static void normalize_task(struct rq *rq, struct task_struct *p)
 {
+        const struct sched_class *prev_class = p->sched_class;
+        int old_prio = p->prio;
         int on_rq;
 
         on_rq = p->se.on_rq;
@@ -8247,6 +8248,8 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
                 activate_task(rq, p, 0);
                 resched_task(rq->curr);
         }
+
+        check_class_changed(rq, p, prev_class, old_prio);
 }
 
 void normalize_rt_tasks(void)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 4cbc9121094c..55040f3938d8 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -4078,33 +4078,62 @@ static void task_fork_fair(struct task_struct *p)
  * Priority of the task has changed. Check to see if we preempt
  * the current task.
  */
-static void prio_changed_fair(struct rq *rq, struct task_struct *p,
-                              int oldprio, int running)
+static void
+prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
 {
+        if (!p->se.on_rq)
+                return;
+
         /*
          * 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 (running) {
+        if (rq->curr == p) {
                 if (p->prio > oldprio)
                         resched_task(rq->curr);
         } else
                 check_preempt_curr(rq, p, 0);
 }
 
+static void switched_from_fair(struct rq *rq, struct task_struct *p)
+{
+        struct sched_entity *se = &p->se;
+        struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+        /*
+         * Ensure the task's vruntime is normalized, so that when its
+         * switched back to the fair class the enqueue_entity(.flags=0) will
+         * do the right thing.
+         *
+         * If it was on_rq, then the dequeue_entity(.flags=0) will already
+         * have normalized the vruntime, if it was !on_rq, then only when
+         * the task is sleeping will it still have non-normalized vruntime.
+         */
+        if (!se->on_rq && p->state != TASK_RUNNING) {
+                /*
+                 * Fix up our vruntime so that the current sleep doesn't
+                 * cause 'unlimited' sleep bonus.
+                 */
+                place_entity(cfs_rq, se, 0);
+                se->vruntime -= cfs_rq->min_vruntime;
+        }
+}
+
 /*
  * We switched to the sched_fair class.
  */
-static void switched_to_fair(struct rq *rq, struct task_struct *p,
-                             int running)
+static void switched_to_fair(struct rq *rq, struct task_struct *p)
 {
+        if (!p->se.on_rq)
+                return;
+
         /*
          * We were most likely switched from sched_rt, so
          * kick off the schedule if running, otherwise just see
          * if we can still preempt the current task.
          */
-        if (running)
+        if (rq->curr == p)
                 resched_task(rq->curr);
         else
                 check_preempt_curr(rq, p, 0);
@@ -4190,6 +4219,7 @@ static const struct sched_class fair_sched_class = {
         .task_fork              = task_fork_fair,
 
         .prio_changed           = prio_changed_fair,
+        .switched_from          = switched_from_fair,
         .switched_to            = switched_to_fair,
 
         .get_rr_interval        = get_rr_interval_fair,
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 41eb62a0808b..c82f26c1b7c3 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -52,14 +52,13 @@ static void set_curr_task_idle(struct rq *rq)
 {
 }
 
-static void
-switched_to_idle(struct rq *rq, struct task_struct *p, int running)
+static void switched_to_idle(struct rq *rq, struct task_struct *p)
 {
         BUG();
 }
 
-static void prio_changed_idle(struct rq *rq, struct task_struct *p,
-                              int oldprio, int running)
+static void
+prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio)
 {
         BUG();
 }
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index c914ec747ca6..c381fdc18c64 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1595,8 +1595,7 @@ static void rq_offline_rt(struct rq *rq)
  * When switch from the rt queue, we bring ourselves to a position
  * that we might want to pull RT tasks from other runqueues.
  */
-static void switched_from_rt(struct rq *rq, struct task_struct *p,
-                           int running)
+static void switched_from_rt(struct rq *rq, struct task_struct *p)
 {
         /*
          * If there are other RT tasks then we will reschedule
@@ -1605,7 +1604,7 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p,
          * we may need to handle the pulling of RT tasks
          * now.
          */
-        if (!rq->rt.rt_nr_running)
+        if (p->se.on_rq && !rq->rt.rt_nr_running)
                 pull_rt_task(rq);
 }
 
@@ -1624,8 +1623,7 @@ static inline void init_sched_rt_class(void)
  * with RT tasks. In this case we try to push them off to
  * other runqueues.
  */
-static void switched_to_rt(struct rq *rq, struct task_struct *p,
-                           int running)
+static void switched_to_rt(struct rq *rq, struct task_struct *p)
 {
         int check_resched = 1;
 
@@ -1636,7 +1634,7 @@ 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 (!running) {
+        if (p->se.on_rq && rq->curr != p) {
 #ifdef CONFIG_SMP
                 if (rq->rt.overloaded && push_rt_task(rq) &&
                     /* Don't resched if we changed runqueues */
@@ -1652,10 +1650,13 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p,
  * Priority of the task has changed. This may cause
  * us to initiate a push or pull.
  */
-static void prio_changed_rt(struct rq *rq, struct task_struct *p,
-                            int oldprio, int running)
+static void
+prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
 {
-        if (running) {
+        if (!p->se.on_rq)
+                return;
+
+        if (rq->curr == p) {
 #ifdef CONFIG_SMP
                 /*
                  * If our priority decreases while running, we
diff --git a/kernel/sched_stoptask.c b/kernel/sched_stoptask.c
index 2bf6b47058c1..84ec9bcf82d9 100644
--- a/kernel/sched_stoptask.c
+++ b/kernel/sched_stoptask.c
@@ -59,14 +59,13 @@ static void set_curr_task_stop(struct rq *rq)
 {
 }
 
-static void switched_to_stop(struct rq *rq, struct task_struct *p,
-                             int running)
+static void switched_to_stop(struct rq *rq, struct task_struct *p)
 {
         BUG(); /* its impossible to change to this class */
 }
 
-static void prio_changed_stop(struct rq *rq, struct task_struct *p,
-                              int oldprio, int running)
+static void
+prio_changed_stop(struct rq *rq, struct task_struct *p, int oldprio)
 {
         BUG(); /* how!?, what priority? */
 }