On Tue, May 12, 2015 at 10:45:29AM +0200, Peter Zijlstra wrote: > On Mon, May 11, 2015 at 10:50:42AM -0700, Linus Torvalds wrote: > > On Mon, May 11, 2015 at 7:54 AM, Peter Zijlstra <[email protected]> > > wrote: > > > > > > Hmm, so I looked at the set_mb() definitions and I figure we want to do > > > something like the below, right? > > > > I don't think you need to do this for the non-smp cases. > > Well, its the store tearing thing again, we use WRITE_ONCE() in > smp_store_release() for the same reason. We want it to be a single > store. > > > The whole > > thing is about smp memory ordering, so on UP you don't even need the > > WRITE_ONCE(), much less a barrier.
Ah, you meant the memory barrier; indeed, a compiler barrier is sufficient. I got somewhat confused between Waiman's email and barrier and barrier() (again!). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
