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| author | Tejun Heo <tj@kernel.org> | 2012-10-18 17:40:30 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-28 10:14:14 -0700 |
| commit | 5993bba302a1a6df9c73690a08346411ff7cd56e (patch) | |
| tree | d10d70343dd1df236e6d16d75de9c107c86f82d1 /kernel/params.c | |
| parent | 9a55fef20afb3d7362b0c9d19ba1e78dfe482d3d (diff) | |
| download | lwn-5993bba302a1a6df9c73690a08346411ff7cd56e.tar.gz lwn-5993bba302a1a6df9c73690a08346411ff7cd56e.zip | |
Revert "cgroup: Remove task_lock() from cgroup_post_fork()"
commit d87838321124061f6c935069d97f37010fa417e6 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/params.c')
0 files changed, 0 insertions, 0 deletions