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* [PATCH] sched: skip autogroup when looking for all rt sched groups
@ 2011-06-22  5:22 Yong Zhang
  2011-06-23 11:21 ` Cheng Xu
  0 siblings, 1 reply; 6+ messages in thread
From: Yong Zhang @ 2011-06-22  5:22 UTC (permalink / raw)
  To: linux-kernel; +Cc: Peter Zijlstra, Ingo Molnar, Mike Galbraith, Cheng Xu

[-- Attachment #1: Type: text/plain, Size: 2632 bytes --]

From: Yong Zhang <yong.zhang0@gmail.com>
Subject: [PATCH] sched: skip autogroup when looking for all rt sched groups

Since [commit ec514c48: sched: Fix rt_rq runtime leakage bug],
'cat /proc/sched_debug' will print data of root_task_group.rt_rq
multi times, this is due to autogroup has no its own rt group,
instead rt group of autogroup is linked to root_task_group.

So skip it when we are looking for all rt sched groups, and it
will also save some noop operation against root_task_group when
__disable_runtime()/__enable_runtime().

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
---

Since webmail may mangle the patch, attach it too.

 kernel/sched_autogroup.h |    1 +
 kernel/sched_rt.c        |   29 ++++++++++++++++++++++++-----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
index 0557705..c2f0e72 100644
--- a/kernel/sched_autogroup.h
+++ b/kernel/sched_autogroup.h
@@ -13,6 +13,7 @@ struct autogroup {
 	int			nice;
 };

+static inline bool task_group_is_autogroup(struct task_group *tg);
 static inline struct task_group *
 autogroup_task_group(struct task_struct *p, struct task_group *tg);

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 10d0182..8edf487 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -185,11 +185,30 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)

 typedef struct task_group *rt_rq_iter_t;

-#define for_each_rt_rq(rt_rq, iter, rq) \
-	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
-	     (&iter->list != &task_groups) && \
-	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
-	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
+/* autogroup is not related to rt group, skip it */
+#define find_first_valid_task_group(iter)				\
+	({								\
+		list_for_each_entry_rcu(iter, &task_groups, list)	\
+			if (!task_group_is_autogroup(iter))		\
+				break;					\
+		iter;							\
+	})
+
+#define find_next_valid_task_group(iter)				\
+	({								\
+		do {							\
+			iter = list_entry_rcu(iter->list.next,		\
+					typeof(*iter),	list);		\
+		} while (&iter->list != &task_groups &&			\
+			task_group_is_autogroup(iter));			\
+		iter;							\
+	})
+
+#define for_each_rt_rq(rt_rq, iter, rq)					\
+	for (find_first_valid_task_group(iter);				\
+	     (&iter->list != &task_groups) &&				\
+	     (rt_rq = iter->rt_rq[cpu_of(rq)]);				\
+	     find_next_valid_task_group(iter))

 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {
-- 
1.7.4.1

[-- Attachment #2: 0001-sched-skip-autogroup-when-looking-for-all-rt-sched-g.patch --]
[-- Type: text/x-patch, Size: 2747 bytes --]

From 40117635a8f22a05a4eed98c40fcaf67ad90f738 Mon Sep 17 00:00:00 2001
From: Yong Zhang <yong.zhang0@gmail.com>
Date: Wed, 22 Jun 2011 12:52:40 +0800
Subject: [PATCH] sched: skip autogroup when looking for all rt sched groups

Since [commit ec514c48: sched: Fix rt_rq runtime leakage bug],
'cat /proc/sched_debug' will print data of root_task_group.rt_rq
multi times, this is due to autogroup has no its own rt group,
instead rt group of autogroup is linked to root_task_group.

So skip it when we are looking for all rt sched groups, and it
will also save some noop operation against root_task_group when
__disable_runtime()/__enable_runtime().

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
---

Since webmail may mangle the patch, attach it too.

 kernel/sched_autogroup.h |    1 +
 kernel/sched_rt.c        |   29 ++++++++++++++++++++++++-----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
index 0557705..c2f0e72 100644
--- a/kernel/sched_autogroup.h
+++ b/kernel/sched_autogroup.h
@@ -13,6 +13,7 @@ struct autogroup {
 	int			nice;
 };
 
+static inline bool task_group_is_autogroup(struct task_group *tg);
 static inline struct task_group *
 autogroup_task_group(struct task_struct *p, struct task_group *tg);
 
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 10d0182..8edf487 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -185,11 +185,30 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 
 typedef struct task_group *rt_rq_iter_t;
 
-#define for_each_rt_rq(rt_rq, iter, rq) \
-	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
-	     (&iter->list != &task_groups) && \
-	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
-	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
+/* autogroup is not related to rt group, skip it */
+#define find_first_valid_task_group(iter)				\
+	({								\
+		list_for_each_entry_rcu(iter, &task_groups, list)	\
+			if (!task_group_is_autogroup(iter))		\
+				break;					\
+		iter;							\
+	})
+
+#define find_next_valid_task_group(iter)				\
+	({								\
+		do {							\
+			iter = list_entry_rcu(iter->list.next,		\
+					typeof(*iter),	list);		\
+		} while (&iter->list != &task_groups &&			\
+			task_group_is_autogroup(iter));			\
+		iter;							\
+	})
+
+#define for_each_rt_rq(rt_rq, iter, rq)					\
+	for (find_first_valid_task_group(iter);				\
+	     (&iter->list != &task_groups) &&				\
+	     (rt_rq = iter->rt_rq[cpu_of(rq)]);				\
+	     find_next_valid_task_group(iter))
 
 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {
-- 
1.7.4.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH] sched: skip autogroup when looking for all rt sched groups
  2011-06-22  5:22 [PATCH] sched: skip autogroup when looking for all rt sched groups Yong Zhang
@ 2011-06-23 11:21 ` Cheng Xu
  2011-06-28  2:40   ` Yong Zhang
  0 siblings, 1 reply; 6+ messages in thread
From: Cheng Xu @ 2011-06-23 11:21 UTC (permalink / raw)
  To: Yong Zhang; +Cc: linux-kernel, Peter Zijlstra, Ingo Molnar, Mike Galbraith

On 06/22/2011 01:22 PM, Yong Zhang wrote:
> From: Yong Zhang <yong.zhang0@gmail.com>
> Subject: [PATCH] sched: skip autogroup when looking for all rt sched groups
> 
> Since [commit ec514c48: sched: Fix rt_rq runtime leakage bug],
> 'cat /proc/sched_debug' will print data of root_task_group.rt_rq
> multi times, this is due to autogroup has no its own rt group,
> instead rt group of autogroup is linked to root_task_group.
> 
> So skip it when we are looking for all rt sched groups, and it
> will also save some noop operation against root_task_group when
> __disable_runtime()/__enable_runtime().
> 
> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Mike Galbraith <efault@gmx.de>
> ---
> 
> Since webmail may mangle the patch, attach it too.
> 
>  kernel/sched_autogroup.h |    1 +
>  kernel/sched_rt.c        |   29 ++++++++++++++++++++++++-----
>  2 files changed, 25 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
> index 0557705..c2f0e72 100644
> --- a/kernel/sched_autogroup.h
> +++ b/kernel/sched_autogroup.h
> @@ -13,6 +13,7 @@ struct autogroup {
>  	int			nice;
>  };
> 
> +static inline bool task_group_is_autogroup(struct task_group *tg);
>  static inline struct task_group *
>  autogroup_task_group(struct task_struct *p, struct task_group *tg);
> 
> diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
> index 10d0182..8edf487 100644
> --- a/kernel/sched_rt.c
> +++ b/kernel/sched_rt.c
> @@ -185,11 +185,30 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
> 
>  typedef struct task_group *rt_rq_iter_t;
> 
> -#define for_each_rt_rq(rt_rq, iter, rq) \
> -	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
> -	     (&iter->list != &task_groups) && \
> -	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
> -	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
> +/* autogroup is not related to rt group, skip it */
> +#define find_first_valid_task_group(iter)				\
> +	({								\
> +		list_for_each_entry_rcu(iter, &task_groups, list)	\
> +			if (!task_group_is_autogroup(iter))		\
> +				break;					\
> +		iter;							\
> +	})
> +
> +#define find_next_valid_task_group(iter)				\
> +	({								\
> +		do {							\
> +			iter = list_entry_rcu(iter->list.next,		\
> +					typeof(*iter),	list);		\
> +		} while (&iter->list != &task_groups &&			\
> +			task_group_is_autogroup(iter));			\
> +		iter;							\
> +	})
> +
> +#define for_each_rt_rq(rt_rq, iter, rq)					\
> +	for (find_first_valid_task_group(iter);				\
> +	     (&iter->list != &task_groups) &&				\
> +	     (rt_rq = iter->rt_rq[cpu_of(rq)]);				\
> +	     find_next_valid_task_group(iter))
> 
>  static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
>  {

This looks like it works, but seems we might be able to do that with less code... 

static inline struct task_group *next_task_group(struct task_group *tg)
{
	do {
		tg = list_entry_rcu(tg->list.next,
		                    typeof(struct task_group), list);
	} while ((&tg->list != &task_groups) && (task_group_is_autogroup(tg)));
	if (&tg->list == &task_groups)
		tg = NULL;
	return tg;
}

#define for_each_rt_rq(rt_rq, iter, rq) \
	for (iter = container_of(&task_groups, typeof(*iter), list); \
	     (iter = next_task_group(iter)) && \
	     (rt_rq = iter->rt_rq[cpu_of(rq)]);)


Thanks,
Cheng

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH] sched: skip autogroup when looking for all rt sched groups
  2011-06-23 11:21 ` Cheng Xu
@ 2011-06-28  2:40   ` Yong Zhang
  2011-06-28  2:51     ` [PATCH V2] " Yong Zhang
  0 siblings, 1 reply; 6+ messages in thread
From: Yong Zhang @ 2011-06-28  2:40 UTC (permalink / raw)
  To: Cheng Xu; +Cc: linux-kernel, Peter Zijlstra, Ingo Molnar, Mike Galbraith

Sorry for my late response and comments below.

On Thu, Jun 23, 2011 at 7:21 PM, Cheng Xu <chengxu@linux.vnet.ibm.com> wrote:
>
> This looks like it works, but seems we might be able to do that with less code...
>
> static inline struct task_group *next_task_group(struct task_group *tg)
> {
>        do {
>                tg = list_entry_rcu(tg->list.next,
>                                    typeof(struct task_group), list);
>        } while ((&tg->list != &task_groups) && (task_group_is_autogroup(tg)));
>        if (&tg->list == &task_groups)
>                tg = NULL;
>        return tg;
> }
>
> #define for_each_rt_rq(rt_rq, iter, rq) \
>        for (iter = container_of(&task_groups, typeof(*iter), list); \
>             (iter = next_task_group(iter)) && \
>             (rt_rq = iter->rt_rq[cpu_of(rq)]);)

Yeah, this works too, and it save some code.

Will update the patch based on it.

Thanks,
Yong



-- 
Only stand for myself

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH V2] sched: skip autogroup when looking for all rt sched groups
  2011-06-28  2:40   ` Yong Zhang
@ 2011-06-28  2:51     ` Yong Zhang
  2011-06-30  3:33       ` Cheng Xu
  2011-07-01 15:17       ` [tip:sched/core] sched: Skip " tip-bot for Yong Zhang
  0 siblings, 2 replies; 6+ messages in thread
From: Yong Zhang @ 2011-06-28  2:51 UTC (permalink / raw)
  To: Cheng Xu; +Cc: linux-kernel, Peter Zijlstra, Ingo Molnar, Mike Galbraith

[-- Attachment #1: Type: text/plain, Size: 2467 bytes --]

From: Yong Zhang <yong.zhang0@gmail.com>
Subject: [PATCH V2] sched: skip autogroup when looking for all rt sched groups

Since [commit ec514c48: sched: Fix rt_rq runtime leakage bug],
'cat /proc/sched_debug' will print data of root_task_group.rt_rq
multi times, this is due to autogroup has no its own rt group,
instead rt group of autogroup is linked to root_task_group.

So skip it when we are looking for all rt sched groups, and it
will also save some noop operation against root_task_group when
__disable_runtime()/__enable_runtime().

V2: Based on Cheng Xu's idea which uses less code.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Cheng Xu <chengxu@linux.vnet.ibm.com>
---

Attach it too in case webmail will mangle the patch.

 kernel/sched_autogroup.h |    1 +
 kernel/sched_rt.c        |   22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
index 0557705..c2f0e72 100644
--- a/kernel/sched_autogroup.h
+++ b/kernel/sched_autogroup.h
@@ -13,6 +13,7 @@ struct autogroup {
 	int			nice;
 };

+static inline bool task_group_is_autogroup(struct task_group *tg);
 static inline struct task_group *
 autogroup_task_group(struct task_struct *p, struct task_group *tg);

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 10d0182..8c04cb2 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -185,11 +185,23 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)

 typedef struct task_group *rt_rq_iter_t;

-#define for_each_rt_rq(rt_rq, iter, rq) \
-	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
-	     (&iter->list != &task_groups) && \
-	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
-	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
+static inline struct task_group *next_task_group(struct task_group *tg)
+{
+	do {
+		tg = list_entry_rcu(tg->list.next,
+			typeof(struct task_group), list);
+	} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
+
+	if (&tg->list == &task_groups)
+		tg = NULL;
+
+	return tg;
+}
+
+#define for_each_rt_rq(rt_rq, iter, rq)					\
+	for (iter = container_of(&task_groups, typeof(*iter), list);	\
+		(iter = next_task_group(iter)) &&			\
+		(rt_rq = iter->rt_rq[cpu_of(rq)]);)

 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {
-- 
1.7.4.1

[-- Attachment #2: 0001-sched-skip-autogroup-when-looking-for-all-rt-sched-g.patch --]
[-- Type: text/x-patch, Size: 2582 bytes --]

From e8ffcca971815ba50d6a83e0acd692aee874e106 Mon Sep 17 00:00:00 2001
From: Yong Zhang <yong.zhang0@gmail.com>
Date: Wed, 22 Jun 2011 12:52:40 +0800
Subject: [PATCH V2] sched: skip autogroup when looking for all rt sched groups

Since [commit ec514c48: sched: Fix rt_rq runtime leakage bug],
'cat /proc/sched_debug' will print data of root_task_group.rt_rq
multi times, this is due to autogroup has no its own rt group,
instead rt group of autogroup is linked to root_task_group.

So skip it when we are looking for all rt sched groups, and it
will also save some noop operation against root_task_group when
__disable_runtime()/__enable_runtime().

V2: Based on Cheng Xu's idea which uses less code.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Cheng Xu <chengxu@linux.vnet.ibm.com>
---

Attach it too in case webmail will mangle the patch.

 kernel/sched_autogroup.h |    1 +
 kernel/sched_rt.c        |   22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
index 0557705..c2f0e72 100644
--- a/kernel/sched_autogroup.h
+++ b/kernel/sched_autogroup.h
@@ -13,6 +13,7 @@ struct autogroup {
 	int			nice;
 };
 
+static inline bool task_group_is_autogroup(struct task_group *tg);
 static inline struct task_group *
 autogroup_task_group(struct task_struct *p, struct task_group *tg);
 
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 10d0182..8c04cb2 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -185,11 +185,23 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 
 typedef struct task_group *rt_rq_iter_t;
 
-#define for_each_rt_rq(rt_rq, iter, rq) \
-	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
-	     (&iter->list != &task_groups) && \
-	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
-	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
+static inline struct task_group *next_task_group(struct task_group *tg)
+{
+	do {
+		tg = list_entry_rcu(tg->list.next,
+			typeof(struct task_group), list);
+	} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
+
+	if (&tg->list == &task_groups)
+		tg = NULL;
+
+	return tg;
+}
+
+#define for_each_rt_rq(rt_rq, iter, rq)					\
+	for (iter = container_of(&task_groups, typeof(*iter), list);	\
+		(iter = next_task_group(iter)) &&			\
+		(rt_rq = iter->rt_rq[cpu_of(rq)]);)
 
 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {
-- 
1.7.4.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH V2] sched: skip autogroup when looking for all rt sched groups
  2011-06-28  2:51     ` [PATCH V2] " Yong Zhang
@ 2011-06-30  3:33       ` Cheng Xu
  2011-07-01 15:17       ` [tip:sched/core] sched: Skip " tip-bot for Yong Zhang
  1 sibling, 0 replies; 6+ messages in thread
From: Cheng Xu @ 2011-06-30  3:33 UTC (permalink / raw)
  To: Yong Zhang; +Cc: linux-kernel, Peter Zijlstra, Ingo Molnar, Mike Galbraith

On 06/28/2011 10:51 AM, Yong Zhang wrote:
> From: Yong Zhang <yong.zhang0@gmail.com>
> Subject: [PATCH V2] sched: skip autogroup when looking for all rt sched groups
> 
> Since [commit ec514c48: sched: Fix rt_rq runtime leakage bug],
> 'cat /proc/sched_debug' will print data of root_task_group.rt_rq
> multi times, this is due to autogroup has no its own rt group,
> instead rt group of autogroup is linked to root_task_group.
> 
> So skip it when we are looking for all rt sched groups, and it
> will also save some noop operation against root_task_group when
> __disable_runtime()/__enable_runtime().
> 
> V2: Based on Cheng Xu's idea which uses less code.
> 
> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Mike Galbraith <efault@gmx.de>
> Cc: Cheng Xu <chengxu@linux.vnet.ibm.com>

The code looks fine, and works for me. 

Reviewed-by: Cheng Xu <chengxu@linux.vnet.ibm.com>

> ---
> 
> Attach it too in case webmail will mangle the patch.
> 
>  kernel/sched_autogroup.h |    1 +
>  kernel/sched_rt.c        |   22 +++++++++++++++++-----
>  2 files changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
> index 0557705..c2f0e72 100644
> --- a/kernel/sched_autogroup.h
> +++ b/kernel/sched_autogroup.h
> @@ -13,6 +13,7 @@ struct autogroup {
>  	int			nice;
>  };
> 
> +static inline bool task_group_is_autogroup(struct task_group *tg);
>  static inline struct task_group *
>  autogroup_task_group(struct task_struct *p, struct task_group *tg);
> 
> diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
> index 10d0182..8c04cb2 100644
> --- a/kernel/sched_rt.c
> +++ b/kernel/sched_rt.c
> @@ -185,11 +185,23 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
> 
>  typedef struct task_group *rt_rq_iter_t;
> 
> -#define for_each_rt_rq(rt_rq, iter, rq) \
> -	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
> -	     (&iter->list != &task_groups) && \
> -	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
> -	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
> +static inline struct task_group *next_task_group(struct task_group *tg)
> +{
> +	do {
> +		tg = list_entry_rcu(tg->list.next,
> +			typeof(struct task_group), list);
> +	} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
> +
> +	if (&tg->list == &task_groups)
> +		tg = NULL;
> +
> +	return tg;
> +}
> +
> +#define for_each_rt_rq(rt_rq, iter, rq)					\
> +	for (iter = container_of(&task_groups, typeof(*iter), list);	\
> +		(iter = next_task_group(iter)) &&			\
> +		(rt_rq = iter->rt_rq[cpu_of(rq)]);)
> 
>  static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
>  {


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [tip:sched/core] sched: Skip autogroup when looking for all rt sched groups
  2011-06-28  2:51     ` [PATCH V2] " Yong Zhang
  2011-06-30  3:33       ` Cheng Xu
@ 2011-07-01 15:17       ` tip-bot for Yong Zhang
  1 sibling, 0 replies; 6+ messages in thread
From: tip-bot for Yong Zhang @ 2011-07-01 15:17 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: linux-kernel, hpa, mingo, a.p.zijlstra, efault, tglx,
	yong.zhang0, chengxu, mingo

Commit-ID:  1c09ab0d257317f97e8629a3d0c8713d6dd9de4c
Gitweb:     http://git.kernel.org/tip/1c09ab0d257317f97e8629a3d0c8713d6dd9de4c
Author:     Yong Zhang <yong.zhang0@gmail.com>
AuthorDate: Tue, 28 Jun 2011 10:51:31 +0800
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 1 Jul 2011 10:39:08 +0200

sched: Skip autogroup when looking for all rt sched groups

Since commit ec514c48 ("sched: Fix rt_rq runtime leakage bug")
'cat /proc/sched_debug' will print data of root_task_group.rt_rq
multiple times.

This is because autogroup does not have its own rt group, instead
rt group of autogroup is linked to root_task_group.

So skip it when we are looking for all rt sched groups, and it
will also save some noop operation against root_task_group when
__disable_runtime()/__enable_runtime().

-v2: Based on Cheng Xu's idea which uses less code.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Cheng Xu <chengxu@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/BANLkTi=87P3RoTF_UEtamNfc_XGxQXE__Q@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/sched_autogroup.h |    1 +
 kernel/sched_rt.c        |   22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/kernel/sched_autogroup.h b/kernel/sched_autogroup.h
index 0557705..c2f0e72 100644
--- a/kernel/sched_autogroup.h
+++ b/kernel/sched_autogroup.h
@@ -13,6 +13,7 @@ struct autogroup {
 	int			nice;
 };
 
+static inline bool task_group_is_autogroup(struct task_group *tg);
 static inline struct task_group *
 autogroup_task_group(struct task_struct *p, struct task_group *tg);
 
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index b03cd89..97540f0 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -185,11 +185,23 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 
 typedef struct task_group *rt_rq_iter_t;
 
-#define for_each_rt_rq(rt_rq, iter, rq) \
-	for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \
-	     (&iter->list != &task_groups) && \
-	     (rt_rq = iter->rt_rq[cpu_of(rq)]); \
-	     iter = list_entry_rcu(iter->list.next, typeof(*iter), list))
+static inline struct task_group *next_task_group(struct task_group *tg)
+{
+	do {
+		tg = list_entry_rcu(tg->list.next,
+			typeof(struct task_group), list);
+	} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
+
+	if (&tg->list == &task_groups)
+		tg = NULL;
+
+	return tg;
+}
+
+#define for_each_rt_rq(rt_rq, iter, rq)					\
+	for (iter = container_of(&task_groups, typeof(*iter), list);	\
+		(iter = next_task_group(iter)) &&			\
+		(rt_rq = iter->rt_rq[cpu_of(rq)]);)
 
 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {

^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-07-01 15:17 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-06-22  5:22 [PATCH] sched: skip autogroup when looking for all rt sched groups Yong Zhang
2011-06-23 11:21 ` Cheng Xu
2011-06-28  2:40   ` Yong Zhang
2011-06-28  2:51     ` [PATCH V2] " Yong Zhang
2011-06-30  3:33       ` Cheng Xu
2011-07-01 15:17       ` [tip:sched/core] sched: Skip " tip-bot for Yong Zhang

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