[PATCH] sched: activate SCHED BATCH expired
To increase the strength of SCHED_BATCH as a scheduling hint we can
activate batch tasks on the expired array since by definition they are
latency insensitive tasks.
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c4fd3fc..78c40dd 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -484,6 +484,7 @@
#define MAX_PRIO (MAX_RT_PRIO + 40)
#define rt_task(p) (unlikely((p)->prio < MAX_RT_PRIO))
+#define batch_task(p) (unlikely((p)->policy == SCHED_BATCH))
/*
* Some day this will be a full-fledged user tracking system..
diff --git a/kernel/sched.c b/kernel/sched.c
index 73bb4d9..dd153d6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -667,9 +667,13 @@
/*
* __activate_task - move a task to the runqueue.
*/
-static inline void __activate_task(task_t *p, runqueue_t *rq)
+static void __activate_task(task_t *p, runqueue_t *rq)
{
- enqueue_task(p, rq->active);
+ prio_array_t *target = rq->active;
+
+ if (batch_task(p))
+ target = rq->expired;
+ enqueue_task(p, target);
rq->nr_running++;
}
@@ -688,7 +692,7 @@
unsigned long long __sleep_time = now - p->timestamp;
unsigned long sleep_time;
- if (unlikely(p->policy == SCHED_BATCH))
+ if (batch_task(p))
sleep_time = 0;
else {
if (__sleep_time > NS_MAX_SLEEP_AVG)