tree 5e24dfb098b57da5c267bef55e6c946c0e320e45
parent ebf44d16ec4619c8a8daeacd987dd86d420ea2c3
author Tejun Heo <tj@kernel.org> 1363229259 -0700
committer Tejun Heo <tj@kernel.org> 1363229259 -0700

workqueue: better define locking rules around worker creation / destruction

When a manager creates or destroys workers, the operations are always
done with the manager_mutex held; however, initial worker creation or
worker destruction during pool release don't grab the mutex.  They are
still correct as initial worker creation doesn't require
synchronization and grabbing manager_arb provides enough exclusion for
pool release path.

Still, let's make everyone follow the same rules for consistency and
such that lockdep annotations can be added.

Update create_and_start_worker() and put_unbound_pool() to grab
manager_mutex around thread creation and destruction respectively and
add lockdep assertions to create_worker() and destroy_worker().

This patch doesn't introduce any visible behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>