From: Andi Kleen <redacted>
Date: Fri, 18 Aug 2006 11:29:14 +0200

So ideal would be something dynamic to turn on/off io placement, maybe based 
on node_distance() again, with the threshold tweakable per architecture?

We have this ugly 'hashdist' thing, let's remove the __initdata tag
on it, give it a useful name, and let architectures set it as
they deem appropriate.