On Thu, 2012-05-17 at 07:10 +1000, Benjamin Herrenschmidt wrote: > I have a long experience with dealing with ordering issues on large SMP > systems and believe me, anything "fine grained" is really really hard to > generally get right, and the resulting bugs are really nasty to track > down and even identify. So I have a strong bias toward the big hammer > approach that is guaranteed to avoid the problem for anything using the > right DMA accessors.
BTW, this is going to also hurt SMP ARMs ... ARM is getting increasingly out of order as well. Cheers, Ben.