Paul Mackerras wrote:
<snip>

> 
> There is a race on PPC with your patch, but I can fix that by removing
> the init_idle() call from smp_callin() in arch/ppc/kernel/smp.c.
> At a quick glance it looks like alpha and sparc (sun4m) may have the
> same problem since they also call init_idle before waiting for
> smp_commence() (or smp_threads_ready != 0).


Okay, I'm attaching a patch to fix the issue on Alpha.  I've tested it 
on both a Wildfire and a Tincup (Rawhide); without the patch both hang 
due to the above race, while with it both boot just fine.  Linus, Alan - 
please apply, unless Jay or Richard come screaming with their hair on 
fire. ;)

  - Pete