On Fri, Aug 29, 2008 at 08:42:01AM +1000, Benjamin Herrenschmidt wrote:

For the non-SMP case, I think it should be possible to optimize it. The
only thing that can happen at interrupt time is hashing of kernel or
vmalloc/ioremap pages, which shouldn't compete with set_pte on those
pages, so there would be no access races there, but I may be missing
something as it's the morning and I about just woke up :-)

Is that still true with preemptible kernels?

-Scott