sched: revert recent removal of set_curr_task()
Revert removal of set_curr_task.
Use put_prev_task/set_curr_task when changing groups/policies
Signed-off-by: Srivatsa Vaddagiri < vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
diff --git a/kernel/sched.c b/kernel/sched.c
index 72c936d..ee7ac71 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3916,7 +3916,7 @@
void rt_mutex_setprio(struct task_struct *p, int prio)
{
unsigned long flags;
- int oldprio, on_rq;
+ int oldprio, on_rq, running;
struct rq *rq;
BUG_ON(prio < 0 || prio > MAX_PRIO);
@@ -3926,8 +3926,12 @@
oldprio = p->prio;
on_rq = p->se.on_rq;
- if (on_rq)
+ running = task_running(rq, p);
+ if (on_rq) {
dequeue_task(rq, p, 0);
+ if (running)
+ p->sched_class->put_prev_task(rq, p);
+ }
if (rt_prio(prio))
p->sched_class = &rt_sched_class;
@@ -3937,13 +3941,15 @@
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);
} else {
@@ -4149,7 +4155,7 @@
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;
@@ -4231,20 +4237,26 @@
}
update_rq_clock(rq);
on_rq = p->se.on_rq;
- if (on_rq)
+ running = task_running(rq, p);
+ if (on_rq) {
deactivate_task(rq, p, 0);
+ 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);
} else {
@@ -6845,13 +6857,19 @@
running = task_running(rq, tsk);
on_rq = tsk->se.on_rq;
- if (on_rq)
+ if (on_rq) {
dequeue_task(rq, tsk, 0);
+ if (unlikely(running))
+ tsk->sched_class->put_prev_task(rq, tsk);
+ }
set_task_cfs_rq(tsk);
- if (on_rq)
+ if (on_rq) {
+ if (unlikely(running))
+ tsk->sched_class->set_curr_task(rq);
enqueue_task(rq, tsk, 0);
+ }
done:
task_rq_unlock(rq, &flags);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 9f93a5c..92563cd 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -472,20 +472,9 @@
}
static void
-enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
- int wakeup, int set_curr)
+enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
{
/*
- * In case of the 'current'.
- */
- if (unlikely(set_curr)) {
- update_stats_curr_start(cfs_rq, se);
- cfs_rq->curr = se;
- account_entity_enqueue(cfs_rq, se);
- return;
- }
-
- /*
* Update the fair clock.
*/
update_curr(cfs_rq);
@@ -496,7 +485,8 @@
}
update_stats_enqueue(cfs_rq, se);
- __enqueue_entity(cfs_rq, se);
+ if (se != cfs_rq->curr)
+ __enqueue_entity(cfs_rq, se);
account_entity_enqueue(cfs_rq, se);
}
@@ -516,12 +506,8 @@
}
}
#endif
- if (likely(se != cfs_rq->curr))
+ if (se != cfs_rq->curr)
__dequeue_entity(cfs_rq, se);
- else {
- update_stats_curr_end(cfs_rq, se);
- cfs_rq->curr = NULL;
- }
account_entity_dequeue(cfs_rq, se);
}
@@ -539,15 +525,20 @@
resched_task(rq_of(cfs_rq)->curr);
}
-static inline void
+static void
set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- /*
- * Any task has to be enqueued before it get to execute on
- * a CPU. So account for the time it spent waiting on the
- * runqueue.
- */
- update_stats_wait_end(cfs_rq, se);
+ /* 'current' is not kept within the tree. */
+ if (se->on_rq) {
+ /*
+ * Any task has to be enqueued before it get to execute on
+ * a CPU. So account for the time it spent waiting on the
+ * runqueue.
+ */
+ update_stats_wait_end(cfs_rq, se);
+ __dequeue_entity(cfs_rq, se);
+ }
+
update_stats_curr_start(cfs_rq, se);
cfs_rq->curr = se;
#ifdef CONFIG_SCHEDSTATS
@@ -568,10 +559,6 @@
{
struct sched_entity *se = __pick_next_entity(cfs_rq);
- /* 'current' is not kept within the tree. */
- if (se)
- __dequeue_entity(cfs_rq, se);
-
set_next_entity(cfs_rq, se);
return se;
@@ -703,17 +690,12 @@
{
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
- int set_curr = 0;
-
- /* Are we enqueuing the current task? */
- if (unlikely(task_running(rq, p)))
- set_curr = 1;
for_each_sched_entity(se) {
if (se->on_rq)
break;
cfs_rq = cfs_rq_of(se);
- enqueue_entity(cfs_rq, se, wakeup, set_curr);
+ enqueue_entity(cfs_rq, se, wakeup);
}
}
@@ -761,7 +743,7 @@
* position within the tree:
*/
dequeue_entity(cfs_rq, se, 0);
- enqueue_entity(cfs_rq, se, 0, 1);
+ enqueue_entity(cfs_rq, se, 0);
return;
}
@@ -1004,6 +986,19 @@
resched_task(rq->curr);
}
+/* Account for a task changing its policy or group.
+ *
+ * This routine is mostly called to set cfs_rq->curr field when a task
+ * migrates between groups/classes.
+ */
+static void set_curr_task_fair(struct rq *rq)
+{
+ struct sched_entity *se = &rq->curr->se;
+
+ for_each_sched_entity(se)
+ set_next_entity(cfs_rq_of(se), se);
+}
+
/*
* All the scheduling class methods:
*/
@@ -1019,6 +1014,7 @@
.load_balance = load_balance_fair,
+ .set_curr_task = set_curr_task_fair,
.task_tick = task_tick_fair,
.task_new = task_new_fair,
};
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 3503fb2..5ebf829 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -50,6 +50,10 @@
{
}
+static void set_curr_task_idle(struct rq *rq)
+{
+}
+
/*
* Simple, special scheduling class for the per-CPU idle tasks:
*/
@@ -66,6 +70,7 @@
.load_balance = load_balance_idle,
+ .set_curr_task = set_curr_task_idle,
.task_tick = task_tick_idle,
/* no .task_new for idle tasks */
};
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 3c77c03..e1d5f1c8 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -218,6 +218,13 @@
}
}
+static void set_curr_task_rt(struct rq *rq)
+{
+ struct task_struct *p = rq->curr;
+
+ p->se.exec_start = rq->clock;
+}
+
static struct sched_class rt_sched_class __read_mostly = {
.enqueue_task = enqueue_task_rt,
.dequeue_task = dequeue_task_rt,
@@ -230,5 +237,6 @@
.load_balance = load_balance_rt,
+ .set_curr_task = set_curr_task_rt,
.task_tick = task_tick_rt,
};