[tip:sched/core] sched: Make initial SCHED_RR timeslace DEF_TIMESLICE

[tip-bot for Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>]

Commit-ID:  de5bdff7a72acc281219be2b8edeeca1fd81c542
Gitweb:     http://git.kernel.org/tip/de5bdff7a72acc281219be2b8edeeca1fd81c542
Author:     Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
AuthorDate: Thu, 16 Feb 2012 14:52:21 +0900
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 22 Feb 2012 12:28:29 +0100

sched: Make initial SCHED_RR timeslace DEF_TIMESLICE

Current the initial SCHED_RR timeslice of init_task is HZ, which means
1s, and is not same as the default SCHED_RR timeslice DEF_TIMESLICE.

Change that initial timeslice to the DEF_TIMESLICE.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
[ s/DEF_TIMESLICE/RR_TIMESLICE/g ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4F3C9995.3010800@ct.jp.nec.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 include/linux/init_task.h |    2 +-
 include/linux/sched.h     |    6 ++++++
 kernel/sched/rt.c         |    4 ++--
 kernel/sched/sched.h      |    4 ----
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 9c66b1a..f994d51 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -149,7 +149,7 @@ extern struct cred init_cred;
 	},								\
 	.rt		= {						\
 		.run_list	= LIST_HEAD_INIT(tsk.rt.run_list),	\
-		.time_slice	= HZ, 					\
+		.time_slice	= RR_TIMESLICE,				\
 		.nr_cpus_allowed = NR_CPUS,				\
 	},								\
 	.tasks		= LIST_HEAD_INIT(tsk.tasks),			\
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5dba2ad..eb5de46 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1234,6 +1234,12 @@ struct sched_rt_entity {
 #endif
 };
 
+/*
+ * default timeslice is 100 msecs (used only for SCHED_RR tasks).
+ * Timeslices get refilled after they expire.
+ */
+#define RR_TIMESLICE		(100 * HZ / 1000)
+
 struct rcu_node;
 
 enum perf_event_task_context {
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index f42ae7f..f70206c 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1972,7 +1972,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
 	if (--p->rt.time_slice)
 		return;
 
-	p->rt.time_slice = DEF_TIMESLICE;
+	p->rt.time_slice = RR_TIMESLICE;
 
 	/*
 	 * Requeue to the end of queue if we are not the only element
@@ -2000,7 +2000,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
 	 * Time slice is 0 for SCHED_FIFO tasks
 	 */
 	if (task->policy == SCHED_RR)
-		return DEF_TIMESLICE;
+		return RR_TIMESLICE;
 	else
 		return 0;
 }
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 8a2c768..c0660a1 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -36,11 +36,7 @@ extern __read_mostly int scheduler_running;
 
 /*
  * These are the 'tuning knobs' of the scheduler:
- *
- * default timeslice is 100 msecs (used only for SCHED_RR tasks).
- * Timeslices get refilled after they expire.
  */
-#define DEF_TIMESLICE		(100 * HZ / 1000)
 
 /*
  * single value that denotes runtime == period, ie unlimited time.