On Tue, Jun 16, 2020 at 08:35:58PM -0700, Andres Freund wrote: > On June 16, 2020 8:24:29 PM PDT, Noah Misch <n...@leadboat.com> wrote: > >Suppose the initializing process does: > > > > pg_atomic_init_u64(&somestruct->atomic, 123); > > somestruct->atomic_ready = true; > > > >In released versions, any process observing atomic_ready==true will > >observe > >the results of the pg_atomic_init_u64(). After the commit from this > >thread, > >that's no longer assured. > > Why did that hold true before? There wasn't a barrier in platforms already > (wherever we know what 64 bit reads/writes have single copy atomicity).
You are right. It didn't hold before.