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* [PATCH] debug cgroup: remove unneeded cgroup_lock
@ 2009-03-12  1:47 Li Zefan
  2009-03-12  2:43 ` Paul Menage
  0 siblings, 1 reply; 3+ messages in thread
From: Li Zefan @ 2009-03-12  1:47 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Paul Menage, LKML, Linux Containers

Since we are in cgroup write handler, so the cgrp is valid, so we
don't have to hold cgroup_mutex when calling cgroup_task_count().
One similar example is in cgroup_tasks_open().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/cgroup_debug.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c
index daca620..0c92d79 100644
--- a/kernel/cgroup_debug.c
+++ b/kernel/cgroup_debug.c
@@ -40,9 +40,7 @@ static u64 taskcount_read(struct cgroup *cont, struct cftype *cft)
 {
 	u64 count;
 
-	cgroup_lock();
 	count = cgroup_task_count(cont);
-	cgroup_unlock();
 	return count;
 }
 
-- 
1.5.4.rc3


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] debug cgroup: remove unneeded cgroup_lock
  2009-03-12  1:47 [PATCH] debug cgroup: remove unneeded cgroup_lock Li Zefan
@ 2009-03-12  2:43 ` Paul Menage
  2009-03-12  2:49   ` Li Zefan
  0 siblings, 1 reply; 3+ messages in thread
From: Paul Menage @ 2009-03-12  2:43 UTC (permalink / raw)
  To: Li Zefan; +Cc: Andrew Morton, LKML, Linux Containers

On Wed, Mar 11, 2009 at 6:47 PM, Li Zefan <lizf@cn.fujitsu.com> wrote:
> Since we are in cgroup write handler, so the cgrp is valid, so we
> don't have to hold cgroup_mutex when calling cgroup_task_count().
> One similar example is in cgroup_tasks_open().
>
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

Acked-by: Paul Menage <menage@google.com>

(Although this conflicts with a patch that I'm about to send out that
moves the code from cgroup_debug.c into cgroup.c to allow internal
details to be reported in the debug.* files.)

> ---
>  kernel/cgroup_debug.c |    2 --
>  1 files changed, 0 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c
> index daca620..0c92d79 100644
> --- a/kernel/cgroup_debug.c
> +++ b/kernel/cgroup_debug.c
> @@ -40,9 +40,7 @@ static u64 taskcount_read(struct cgroup *cont, struct cftype *cft)
>  {
>        u64 count;
>
> -       cgroup_lock();
>        count = cgroup_task_count(cont);
> -       cgroup_unlock();
>        return count;
>  }
>
> --
> 1.5.4.rc3
>
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] debug cgroup: remove unneeded cgroup_lock
  2009-03-12  2:43 ` Paul Menage
@ 2009-03-12  2:49   ` Li Zefan
  0 siblings, 0 replies; 3+ messages in thread
From: Li Zefan @ 2009-03-12  2:49 UTC (permalink / raw)
  To: Paul Menage; +Cc: Andrew Morton, LKML, Linux Containers

Paul Menage wrote:
> On Wed, Mar 11, 2009 at 6:47 PM, Li Zefan <lizf@cn.fujitsu.com> wrote:
>> Since we are in cgroup write handler, so the cgrp is valid, so we
>> don't have to hold cgroup_mutex when calling cgroup_task_count().
>> One similar example is in cgroup_tasks_open().
>>
>> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> 
> Acked-by: Paul Menage <menage@google.com>
> 
> (Although this conflicts with a patch that I'm about to send out that
> moves the code from cgroup_debug.c into cgroup.c to allow internal
> details to be reported in the debug.* files.)
> 

or let cgroup.c #include <cgroup_debug.c> ?


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2009-03-12  2:49 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2009-03-12  1:47 [PATCH] debug cgroup: remove unneeded cgroup_lock Li Zefan
2009-03-12  2:43 ` Paul Menage
2009-03-12  2:49   ` Li Zefan

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