sched: RT-balance, replace hooks with pre/post schedule and wakeup methods
To make the main sched.c code more agnostic to the schedule classes.
Instead of having specific hooks in the schedule code for the RT class
balancing. They are replaced with a pre_schedule, post_schedule
and task_wake_up methods. These methods may be used by any of the classes
but currently, only the sched_rt class implements them.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2e69f19..c67d2c2 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -843,6 +843,9 @@
int (*move_one_task) (struct rq *this_rq, int this_cpu,
struct rq *busiest, struct sched_domain *sd,
enum cpu_idle_type idle);
+ void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
+ void (*post_schedule) (struct rq *this_rq);
+ void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
#endif
void (*set_curr_task) (struct rq *rq);
diff --git a/kernel/sched.c b/kernel/sched.c
index 9d6fb73..2368a0d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1625,7 +1625,10 @@
out_running:
p->state = TASK_RUNNING;
- wakeup_balance_rt(rq, p);
+#ifdef CONFIG_SMP
+ if (p->sched_class->task_wake_up)
+ p->sched_class->task_wake_up(rq, p);
+#endif
out:
task_rq_unlock(rq, &flags);
@@ -1748,7 +1751,10 @@
inc_nr_running(p, rq);
}
check_preempt_curr(rq, p);
- wakeup_balance_rt(rq, p);
+#ifdef CONFIG_SMP
+ if (p->sched_class->task_wake_up)
+ p->sched_class->task_wake_up(rq, p);
+#endif
task_rq_unlock(rq, &flags);
}
@@ -1869,7 +1875,10 @@
prev_state = prev->state;
finish_arch_switch(prev);
finish_lock_switch(rq, prev);
- schedule_tail_balance_rt(rq);
+#ifdef CONFIG_SMP
+ if (current->sched_class->post_schedule)
+ current->sched_class->post_schedule(rq);
+#endif
fire_sched_in_preempt_notifiers(current);
if (mm)
@@ -3638,7 +3647,10 @@
switch_count = &prev->nvcsw;
}
- schedule_balance_rt(rq, prev);
+#ifdef CONFIG_SMP
+ if (prev->sched_class->pre_schedule)
+ prev->sched_class->pre_schedule(rq, prev);
+#endif
if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 3ea0cae..a5a4510 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -689,14 +689,14 @@
return ret;
}
-static void schedule_balance_rt(struct rq *rq, struct task_struct *prev)
+static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
{
/* Try to pull RT tasks here if we lower this rq's prio */
if (unlikely(rt_task(prev)) && rq->rt.highest_prio > prev->prio)
pull_rt_task(rq);
}
-static void schedule_tail_balance_rt(struct rq *rq)
+static void post_schedule_rt(struct rq *rq)
{
/*
* If we have more than one rt_task queued, then
@@ -713,10 +713,9 @@
}
-static void wakeup_balance_rt(struct rq *rq, struct task_struct *p)
+static void task_wake_up_rt(struct rq *rq, struct task_struct *p)
{
- if (unlikely(rt_task(p)) &&
- !task_running(rq, p) &&
+ if (!task_running(rq, p) &&
(p->prio >= rq->rt.highest_prio) &&
rq->rt.overloaded)
push_rt_tasks(rq);
@@ -780,11 +779,6 @@
if (rq->rt.overloaded)
rt_clear_overload(rq);
}
-
-#else /* CONFIG_SMP */
-# define schedule_tail_balance_rt(rq) do { } while (0)
-# define schedule_balance_rt(rq, prev) do { } while (0)
-# define wakeup_balance_rt(rq, p) do { } while (0)
#endif /* CONFIG_SMP */
static void task_tick_rt(struct rq *rq, struct task_struct *p)
@@ -840,6 +834,9 @@
.set_cpus_allowed = set_cpus_allowed_rt,
.join_domain = join_domain_rt,
.leave_domain = leave_domain_rt,
+ .pre_schedule = pre_schedule_rt,
+ .post_schedule = post_schedule_rt,
+ .task_wake_up = task_wake_up_rt,
#endif
.set_curr_task = set_curr_task_rt,
