diff options
| author | Tejun Heo <tj@kernel.org> | 2012-10-18 17:52:07 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-28 10:14:14 -0700 |
| commit | 727fa37e405a71dc1c7208ea7352be55e0310eca (patch) | |
| tree | 43de8999a864592379df86384426ad2ebf1038fa /kernel/kexec.c | |
| parent | 5993bba302a1a6df9c73690a08346411ff7cd56e (diff) | |
Revert "cgroup: Drop task_lock(parent) on cgroup_fork()"
commit 9bb71308b8133d643648776243e4d5599b1c193d upstream.
This reverts commit 7e381b0eb1e1a9805c37335562e8dc02e7d7848c.
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>
Bitterly-Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/kexec.c')
0 files changed, 0 insertions, 0 deletions