| commit | d87838321124061f6c935069d97f37010fa417e6 | |
| author | Tejun Heo <tj@kernel.org> | |
| Fri, 19 Oct 2012 00:40:30 +0000 (18 17:40 -0700) | ||
| committer | Tejun Heo <tj@kernel.org> | |
| Fri, 19 Oct 2012 21:09:35 +0000 (19 14:09 -0700) | ||
| tree | 825e291d0ad7bdc7e7eb68e4bb829121de2586bc | treesnapshot (tar.gz zip) |
| parent | 9bb71308b8133d643648776243e4d5599b1c193d | commitdiff |
Revert "cgroup: Remove task_lock() from cgroup_post_fork()"
This reverts commit 7e3aa30ac8c904a706518b725c451bb486daaae9.
The commit incorrectly assumed that fork path always performed
threadgroup_change_begin/end() and depended on that for
synchronization against task exit and cgroup migration paths instead
of explicitly grabbing task_lock().
threadgroup_change is not locked when forking a new process (as
opposed to a new thread in the same process) and even if it were it
wouldn't be effective as different processes use different threadgroup
locks.
Revert the incorrect optimization.
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <20121008020000.GB2575@localhost>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
This reverts commit 7e3aa30ac8c904a706518b725c451bb486daaae9.
The commit incorrectly assumed that fork path always performed
threadgroup_change_begin/end() and depended on that for
synchronization against task exit and cgroup migration paths instead
of explicitly grabbing task_lock().
threadgroup_change is not locked when forking a new process (as
opposed to a new thread in the same process) and even if it were it
wouldn't be effective as different processes use different threadgroup
locks.
Revert the incorrect optimization.
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <20121008020000.GB2575@localhost>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
| kernel/cgroup.c | diffblobblamehistory |