On Wed, Sep 16, 2015 at 12:49:18PM +0100, Boqun Feng wrote: > Hi Will, Hello, > On Tue, Sep 15, 2015 at 05:13:30PM +0100, Will Deacon wrote: > > +If necessary, ordering can be enforced by use of an > > +smp_mb__release_acquire() barrier: > > + > > + *A = a; > > + RELEASE M > > + smp_mb__release_acquire(); > > Should this barrier be placed after the ACQUIRE? Because we do actually > want(?) and allow RELEASE and ACQUIRE operations to reorder in this > case, like your following example, right? I think it's a lot simpler to keep it where it is, in all honesty. The relaxation for the RELEASE/ACQUIRE access ordering is mainly there to allow architectures building those operations out of explicit barriers to get away without a definition of smp_mb__release_acquire. Will -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
