cgroup: remove bogus comments
We never grab cgroup mutex in fork and exit paths no matter whether
notify_on_release is set or not.
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d739a73..4ddc755 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -967,14 +967,6 @@
* knows that the cgroup won't be removed, as cgroup_rmdir()
* needs that mutex.
*
- * The fork and exit callbacks cgroup_fork() and cgroup_exit(), don't
- * (usually) take cgroup_mutex. These are the two most performance
- * critical pieces of code here. The exception occurs on cgroup_exit(),
- * when a task in a notify_on_release cgroup exits. Then cgroup_mutex
- * is taken, and if the cgroup count is zero, a usermode call made
- * to the release agent with the name of the cgroup (path relative to
- * the root of cgroup file system) as the argument.
- *
* A cgroup can only be deleted if both its 'count' of using tasks
* is zero, and its list of 'children' cgroups is empty. Since all
* tasks in the system use _some_ cgroup, and since there is always at