On Wed, 19 Oct 2022, Paul E. McKenney wrote: > It is not obvious to the casual user why it is absolutely necessary to > acquire a reference to a SLAB_DESTROY_BY_RCU structure before acquiring > a lock in that structure. Therefore, add a comment explaining this point. Sorry but this is not correct and difficult to comprehend. 1. You do not need a reference to a slab object after it was allocated. Objects must be properly protected by rcu_locks. 2. Locks are initialized once on slab allocation via a constructor (*not* on object allocation via kmem_cache_alloc) 3. Modifying locks at allocation/free is not possible since references to these objects may still persist after free and before alloc. 4. The old term SLAB_DESTROY_BY_RCU is used here.
