On Wed, 12 Jun 2024 20:38:02 -0700 Paul E. McKenney wrote: > o Make rcu_barrier() wait for kfree_rcu() objects. (This is > surprisingly complex and will wait unnecessarily in some cases. > However, it does preserve current code.) Not sure how much mental capacity for API variations we expect from people using caches, but I feel like this would score the highest on Rusty's API scale. I'd even venture an opinion that it's less confusing to require cache users to have their own (trivial) callbacks than add API variants we can't error check even at runtime...