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authorPeter Zijlstra <peterz@infradead.org>2015-06-11 14:46:43 +0200
committerBen Hutchings <ben@decadent.org.uk>2016-06-15 21:29:36 +0100
commit20b8c4901d51a70bbc7d553ebea61473beecd26c (patch)
tree8416ab4092ba6458c3b1df71ee0d93fdd7a29e20
parent7890f43f6310e44ffaced396dd352551ab1ee195 (diff)
sched, dl: Convert switched_{from, to}_dl() / prio_changed_dl() to balance callbacks
commit 9916e214998a4a363b152b637245e5c958067350 upstream. Remove the direct {push,pull} balancing operations from switched_{from,to}_dl() / prio_changed_dl() and use the balance callback queue. Again, err on the side of too many reschedules; since too few is a hard bug while too many is just annoying. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: ktkhai@parallels.com Cc: rostedt@goodmis.org Cc: juri.lelli@gmail.com Cc: pang.xunlei@linaro.org Cc: oleg@redhat.com Cc: wanpeng.li@linux.intel.com Cc: umgwanakikbuti@gmail.com Link: http://lkml.kernel.org/r/20150611124742.968262663@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [Conflicts: kernel/sched/deadline.c] Signed-off-by: Byungchul Park <byungchul.park@lge.com> [bwh: Backported to 3.16: - The check_resched / !CONFIG_SMP case in switched_to_dl() is different - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--kernel/sched/deadline.c36
1 files changed, 21 insertions, 15 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 12c892736976..ab8b917ce8f6 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -213,16 +213,23 @@ static inline bool need_pull_dl_task(struct rq *rq, struct task_struct *prev)
return dl_task(prev);
}
-static DEFINE_PER_CPU(struct callback_head, dl_balance_head);
+static DEFINE_PER_CPU(struct callback_head, dl_push_head);
+static DEFINE_PER_CPU(struct callback_head, dl_pull_head);
static void push_dl_tasks(struct rq *);
+static void pull_dl_task(struct rq *);
static inline void queue_push_tasks(struct rq *rq)
{
if (!has_pushable_dl_tasks(rq))
return;
- queue_balance_callback(rq, &per_cpu(dl_balance_head, rq->cpu), push_dl_tasks);
+ queue_balance_callback(rq, &per_cpu(dl_push_head, rq->cpu), push_dl_tasks);
+}
+
+static inline void queue_pull_task(struct rq *rq)
+{
+ queue_balance_callback(rq, &per_cpu(dl_pull_head, rq->cpu), pull_dl_task);
}
#else
@@ -259,6 +266,10 @@ static inline void pull_dl_task(struct rq *rq)
static inline void queue_push_tasks(struct rq *rq)
{
}
+
+static inline void queue_pull_task(struct rq *rq)
+{
+}
#endif /* CONFIG_SMP */
static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags);
@@ -956,8 +967,6 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
resched_task(rq->curr);
}
-static void pull_dl_task(struct rq *this_rq);
-
#endif /* CONFIG_SMP */
/*
@@ -1562,7 +1571,7 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p)
* from an overloaded cpu, if any.
*/
if (!rq->dl.dl_nr_running)
- pull_dl_task(rq);
+ queue_pull_task(rq);
#endif
}
@@ -1572,8 +1581,6 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p)
*/
static void switched_to_dl(struct rq *rq, struct task_struct *p)
{
- int check_resched = 1;
-
/*
* If p is throttled, don't consider the possibility
* of preempting rq->curr, the check will be done right
@@ -1584,12 +1591,12 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
if (p->on_rq && rq->curr != p) {
#ifdef CONFIG_SMP
- if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p))
- /* Only reschedule if pushing failed */
- check_resched = 0;
-#endif /* CONFIG_SMP */
- if (check_resched && task_has_dl_policy(rq->curr))
+ if (rq->dl.overloaded)
+ queue_push_tasks(rq);
+#else
+ if (task_has_dl_policy(rq->curr))
check_preempt_curr_dl(rq, p, 0);
+#endif /* CONFIG_SMP */
}
}
@@ -1609,15 +1616,14 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p,
* or lowering its prio, so...
*/
if (!rq->dl.overloaded)
- pull_dl_task(rq);
+ queue_pull_task(rq);
/*
* If we now have a earlier deadline task than p,
* then reschedule, provided p is still on this
* runqueue.
*/
- if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline) &&
- rq->curr == p)
+ if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline))
resched_task(p);
#else
/*