From: Johannes Berg <johannes@sipsolutions.net>
Date: Thu, 24 Apr 2008 11:21:52 +0200

Hmm. Why is that whole cpu_clock stuff in place anyway? powerpc has
perfectly synchronised time across processors with dirt cheap access to
it as well, so why build all this code that only messes it up on top of
it?

Same on sparc64.  These changes add more bugs than they fix.