Re: [lttng-dev] [PATCH v2 05/12] urcu/uatomic: Add CMM memory model
Olivier Dion via lttng-dev <[email protected]>
| Newsgroups | org.lttng.lists.lttng-dev |
|---|---|
| Organization | EfficiOS |
| Message-ID | <87bkgyjjsz.fsf@laura> |
On Wed, 21 Jun 2023, "Paul E. McKenney" <[email protected]> wrote: > On Wed, Jun 07, 2023 at 02:53:52PM -0400, Olivier Dion wrote: >> -#ifdef __URCU_DEREFERENCE_USE_ATOMIC_CONSUME >> -# define _rcu_dereference(p) __extension__ ({ \ >> - __typeof__(__extension__ ({ \ >> - __typeof__(p) __attribute__((unused)) _________p0 = { 0 }; \ >> - _________p0; \ >> - })) _________p1; \ >> - __atomic_load(&(p), &_________p1, __ATOMIC_CONSUME); \ > > There is talk of getting rid of memory_order_consume. But for the moment, > it is what there is. Another alternative is to use a volatile load, > similar to old-style CMM_LOAD_SHARED() or in-kernel READ_ONCE(). I think we can stick to __ATOMIC_CONSUME for now. Hopefully getting rid of it means it will be an alias for __ATOMIC_ACQUIRE for ever. -- Olivier Dion EfficiOS Inc. https://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev