On Thu, 2014-04-17 at 16:00 +0200, Peter Zijlstra wrote: > So the non-relaxed ops already imply the expensive I/O barrier (mmiowb?) > and therefore, PPC can drop it from spin_unlock()? We play a trick. We set a per-cpu flag in writeX and test it in unlock before doing the barrier. Still better than having the barrier in every MMIO at this stage for us. Whether we want to change that with then new scheme ... we'll see. > Also, I read mmiowb() as MMIO-write-barrier(), what do we have to > order/contain mmio-reads? > > I have _0_ experience with MMIO, so I've no idea if ordering/containing > reads is silly or not. I will review the rest when I'm back from vacation (or maybe this week-end). Thanks Will for picking that up, it's long overdue :) Cheers, Ben. -- 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
