On Thu, Jul 12, 2018 at 10:28:38AM -0700, Paul E. McKenney wrote: > Look for the uses of raw_spin_lock_irq_rcu_node() and friends in > kernel/rcu and include/linux/*rcu*, along with the explanation in > Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html > > I must confess that I am not following exactly what Peter is calling > out as the failure. My best guess is that he is leading up to his > call for RCsc locks, but I might have missed a turn.
Yes, it is part of my call for RCsc locks. The locking pattern is fairly simple and shows where RCpc comes apart from expectation real nice. Yes I helped clean up the barrier usage, but as always it'd be even cleaner if we could just do away with the special barrier entirely.
