sched: Push put_prev_task() into pick_next_task()
In order to avoid having to do put/set on a whole cgroup hierarchy
when we context switch, push the put into pick_next_task() so that
both operations are in the same function. Further changes then allow
us to possibly optimize away redundant work.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index fdb6bb0..a4147c9 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -23,16 +23,20 @@
/* we're never preempted */
}
-static struct task_struct *pick_next_task_stop(struct rq *rq)
+static struct task_struct *
+pick_next_task_stop(struct rq *rq, struct task_struct *prev)
{
struct task_struct *stop = rq->stop;
- if (stop && stop->on_rq) {
- stop->se.exec_start = rq_clock_task(rq);
- return stop;
- }
+ if (!stop || !stop->on_rq)
+ return NULL;
- return NULL;
+ if (prev)
+ prev->sched_class->put_prev_task(rq, prev);
+
+ stop->se.exec_start = rq_clock_task(rq);
+
+ return stop;
}
static void
