From: Yong Zhang <[email protected]>
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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
---
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
On 06/22/2011 01:22 PM, Yong Zhang wrote:
> From: Yong Zhang <[email protected]>
> 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 <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Mike Galbraith <[email protected]>
> ---
>
> 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
Sorry for my late response and comments below.
On Thu, Jun 23, 2011 at 7:21 PM, Cheng Xu <[email protected]> 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
From: Yong Zhang <[email protected]>
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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Cheng Xu <[email protected]>
---
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
On 06/28/2011 10:51 AM, Yong Zhang wrote:
> From: Yong Zhang <[email protected]>
> 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 <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Mike Galbraith <[email protected]>
> Cc: Cheng Xu <[email protected]>
The code looks fine, and works for me.
Reviewed-by: Cheng Xu <[email protected]>
> ---
>
> 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)
> {