2012-02-16 05:54:09

by Hiroshi Shimamoto

Subject: [PATCH] sched: Make initial SCHED_RR timeslace DEF_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 that initial timeslice to the DEF_TIMESLICE.

Signed-off-by: Hiroshi Shimamoto <[email protected]>
---
include/linux/init_task.h | 2 +-
include/linux/sched.h | 6 ++++++
kernel/sched/sched.h | 4 ----
3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 9c66b1a..d04d67d 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 = DEF_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 3dbc6b5..e84315a 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 DEF_TIMESLICE (100 * HZ / 1000)
+
struct rcu_node;

enum perf_event_task_context {
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.
--
1.7.7.6

2012-02-20 13:31:04

by Peter Zijlstra

Subject: Re: [PATCH] sched: Make initial SCHED_RR timeslace DEF_TIMESLICE

On Thu, 2012-02-16 at 14:52 +0900, Hiroshi Shimamoto wrote:
> 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 that initial timeslice to the DEF_TIMESLICE.
>
> Signed-off-by: Hiroshi Shimamoto <[email protected]>

No real objection, should we take the opportunity to rename to
RR_TIMESLICE or somesuch?

2012-02-21 07:30:51

by Hiroshi Shimamoto

Subject: [PATCH v2] sched: Make initial SCHED_RR timeslace RR_TIMESLICE

(2012/02/20 22:30), Peter Zijlstra wrote:
> On Thu, 2012-02-16 at 14:52 +0900, Hiroshi Shimamoto wrote:
>> 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 that initial timeslice to the DEF_TIMESLICE.
>>
>> Signed-off-by: Hiroshi Shimamoto <[email protected]>
>
> No real objection, should we take the opportunity to rename to
> RR_TIMESLICE or somesuch?
>

sounds reasonable.

===
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/sched.h | 4 ----
3 files changed, 7 insertions(+), 5 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 2df7646..ee882cb 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/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.
--
1.7.7.6

2012-02-21 10:21:20

by Peter Zijlstra

Subject: Re: [PATCH v2] sched: Make initial SCHED_RR timeslace RR_TIMESLICE

On Tue, 2012-02-21 at 16:29 +0900, Hiroshi Shimamoto wrote:
> sounds reasonable.

Thanks!

2012-02-21 11:26:03

by Hiroshi Shimamoto

Subject: Re: [PATCH v2] sched: Make initial SCHED_RR timeslace RR_TIMESLICE

2012/2/21 Hiroshi Shimamoto <[email protected]>:
> (2012/02/20 22:30), Peter Zijlstra wrote:
>> On Thu, 2012-02-16 at 14:52 +0900, Hiroshi Shimamoto wrote:
>>> 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 that initial timeslice to the DEF_TIMESLICE.
>>>
>>> Signed-off-by: Hiroshi Shimamoto <[email protected]>
>>
>> No real objection, should we take the opportunity to rename to
>> RR_TIMESLICE or somesuch?
>>
>
> sounds reasonable.

Oops, the below patch is wrong.
Definitely I missed something.

Will resend, sorry about that.

>
> ===
> 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/sched.h ? ? ?| ? ?4 ----
> ?3 files changed, 7 insertions(+), 5 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 2df7646..ee882cb 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/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.
> --
> 1.7.7.6
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at ?http://www.tux.org/lkml/

2012-02-21 11:27:35

by Peter Zijlstra

Subject: Re: [PATCH v2] sched: Make initial SCHED_RR timeslace RR_TIMESLICE

On Tue, 2012-02-21 at 20:25 +0900, Hiroshi Shimamoto wrote:
> Definitely I missed something.
>
> Will resend, sorry about that.

no worries, already fixed it up..

2012-02-22 16:13:25

by Hiroshi Shimamoto

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

Commit-ID: de5bdff7a72acc281219be2b8edeeca1fd81c542
Gitweb: http://git.kernel.org/tip/de5bdff7a72acc281219be2b8edeeca1fd81c542
Author: Hiroshi Shimamoto <[email protected]>
AuthorDate: Thu, 16 Feb 2012 14:52:21 +0900
Committer: Ingo Molnar <[email protected]>
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 <[email protected]>
[ s/DEF_TIMESLICE/RR_TIMESLICE/g ]
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[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(-)

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.