We introduced the following commit to detect deadlocks caused by wait_for_completion() in flush_{workqueue, work}() and other locks. But now LOCKDEP_COMPLETIONS is introduced, such works are automatically done by LOCKDEP_COMPLETIONS.
commit 4e6045f134784f4b158b3c0f7a282b04bd816887 workqueue: debug flushing deadlocks with lockdep However, LOCKDEP_COMPLETIONS has limitation that it cannot report deadlocks at the real time. So we have to leave some annotations for now, but some redundant acquisitions can be removed. And we need to make workqueue code co-work with LOCKDEP_COMPLETIONS. Byungchul Park (3): lockdep: Use enum type on hlock->read instead of magic number lockdep: Introduce lock_acquire_might() lockdep: Remove unnecessary acquisitions wrt workqueue flush include/linux/lockdep.h | 2 ++ kernel/locking/lockdep.c | 56 ++++++++++++++++++++++++++++++++++-------------- kernel/workqueue.c | 18 +++++++--------- 3 files changed, 50 insertions(+), 26 deletions(-) -- 1.9.1