On Thu, 2011-08-18 at 14:40 -0700, Andrew Morton wrote:

I think I'll apply it, as the call frequency is low (correct?) and the
problem will correct itself as other architectures implement their
atomic this_cpu_foo() operations. 

Which leads me to wonder, can anything but x86 implement that this_cpu_*
muck? I doubt any of the risk chips can actually do all this.
Maybe Itanic, but then that seems to be dying fast.