debug cgroup: remove unneeded cgroup_lock

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 <[email protected]>

---
 kernel/cgroup_debug.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

kernel/cgroup_debug.c +0 -3

index daca620..0c92d79 100644
@@ -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

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 <[email protected]>

---
 kernel/cgroup_debug.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

kernel/cgroup_debug.c +0 -3

index daca620..0c92d79 100644
@@ -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

Quoted 4 lines · Li Zefan

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().

Quoted 1 line

Signed-off-by Li Zefan <[email protected]>

Acked-by Paul Menage <[email protected]>

(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.)

Quoted 4 lines · Li Zefan

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().

Quoted 1 line

Signed-off-by Li Zefan <[email protected]>

Acked-by Paul Menage <[email protected]>

(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.)