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sched: Make initial SCHED_RR timeslace RR_TIMESLICE

PATCH New Hiroshi Shimamoto 1 participant 1 message Feb 22, 2012 Scheduler

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Hiroshi Shimamoto

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PATCH v3 1/1 sched: Make initial SCHED_RR timeslace RR_TIMESLICE

From: Hiroshi Shimamoto <[email protected]>

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 the initial timeslice to the RR_TIMESLICE, which is renamed from DEF_TIMESLICE to clarify it's for SCHED_RR.

Signed-off-by Hiroshi Shimamoto <[email protected]>
CC Peter Zijlstra <[email protected]>
---
 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(-)
include/linux/init_task.h +1 -1
index 9c66b1a..f994d51 100644
@@ -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),			\
include/linux/sched.h +6 -0
index 2df7646..ee882cb 100644
@@ -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 {
kernel/sched/rt.c +2 -2
index f42ae7f..f70206c 100644
@@ -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;
 }
kernel/sched/sched.h +0 -4
index 8a2c768..c0660a1 100644
@@ -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.
Signature · 1 line
1.7.7.6