On Thu, Aug 24, 2017 at 03:11:53PM +0900, Byungchul Park wrote: > On Wed, Aug 23, 2017 at 07:47:14PM +0200, Peter Zijlstra wrote: > > Those are fine and are indeed the flush_work() vs work inversion. > > > > The two straight forward annotations are: > > > > flush_work(work) process_one_work(wq, work) > > A(work) A(work) > > R(work) work->func(work); > > R(work) > > > > Which catches: > > > > Task-1: work: > > > > mutex_lock(&A); mutex_lock(&A); > > flush_work(work); > > I'm not sure but, with LOCKDEP_COMPLETE enabled, this issue would > automatically be covered w/o additional A(work)/R(work). Right? > > A(work)/R(work) seem to be used for preventing wait_for_completion() > in flush_work() from waiting for the completion forever because of the > work using mutex_lock(&A). Am I understanding correctly? > > If yes, we can use just LOCKDEP_COMPLETE for that purpose.
I'm not familiar with workqueue but, the manual lockdep_map_acquire() in workqueue code seems to be introduced to do what LOCKDEP_COMPLETE does for wait_for_completion() and complete(). Wrong?
