Add an interface for a user-defined workqueue lockdep map, which is helpful when multiple workqueues are created for the same purpose. This also helps avoid leaking lockdep maps on each workqueue creation. v2: - Add alloc_workqueue_lockdep_map (Tejun) v3: - Drop __WQ_USER_OWNED_LOCKDEP (Tejun) - static inline alloc_ordered_workqueue_lockdep_map (Tejun) Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Matthew Brost <matthew.brost@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>