On Thu, Oct 03, 2024 at 09:30:53AM -0400, Mathieu Desnoyers wrote: [...] > > > + /* > > > + * Use RCU dereference without lockdep checks, because > > > + * lockdep is not aware of HP guarantees. > > > + */ > > > + addr2 = rcu_access_pointer(*addr_p); /* Load A */ > > > > Why rcu_access_pointer() instead of READ_ONCE()? Because you want to > > mark the head of address dependency? > > Yes, the intent here is to mark the address dependency and provide > a publication guarantee similar to RCU pairing rcu_assign_pointer > and rcu_dereference. Do you see any reason why READ_ONCE() would > suffice here ?
READ_ONCE() also provides address dependencies. See the "DEPENDENCY RELATIONS: data, addr, and ctrl" section in tools/memory-model/Documentation/explanantion.txt. Regards, Boqun > > Thanks, > > Mathieu >
