Re: [Userspace RCU] - rcu_dereference() memory ordering

2024-10-21 Thread Paul E. McKenney via lttng-dev
On Mon, Oct 21, 2024 at 03:53:04PM -0400, Olivier Dion wrote: > Hi Paul, > > In liburcu, `rcu_dereference()' is either implemented with volatile > access with `CMM_LOAD_SHARED()' followed by a memory barrier depends, or > a atomic load with CONSUME memory ordering (configurable by users on a > com

[lttng-dev] [Userspace RCU] - rcu_dereference() memory ordering

2024-10-21 Thread Olivier Dion via lttng-dev
Hi Paul, In liburcu, `rcu_dereference()' is either implemented with volatile access with `CMM_LOAD_SHARED()' followed by a memory barrier depends, or a atomic load with CONSUME memory ordering (configurable by users on a compilation unit basis). However, it is my understanding that the CONSUME me