From: Li Zefan Date: Wed, 17 Sep 2014 10:19:24 +0000 (+0800) Subject: cgroup: remove bogus comments X-Git-Tag: firefly_0821_release~176^2~3097^2~9 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0c8fc2c1210556434835adfb2274f41704853e8a;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Tejun Heo --- diff --git a/kernel/cgroup.c b/kernel/cgroup.c index d739a732edb9..4ddc75588983 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -967,14 +967,6 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task, * 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