14.2.10.1.3 Read Memory Barriers

A read barrier is a data dependency barrier plus a guarantee that all the LOAD operations specified before the barrier will appear to happen before all the LOAD operations specified after the barrier with respect to the other components of the system.

A read barrier is a partial ordering on loads only; it is not required to have any effect on stores.

Read memory barriers imply data dependency barriers, and so can substitute for them.

$\dagger$ Note that read barriers should normally be paired with write barriers; see the "SMP barrier pairing" subsection.



Paul E. McKenney 2011-12-16