New 2.5.14 Hotplug CPU Work

Hi all,

After some delay, a new scratch implementation of hotplug CPU
for x86 is available:

www.[country].kernel.org/pub/linux/kernel/people/rusty

1) Cleans up the init thread creation code so it's workable after boot.
2) Removes the number/logical mapping of CPUs, and smp_num_cpus().
3) Changes the boot sequence so it all happens on UP, then the other CPUs are "plugged in".

I'm pretty happy with the simpler boot code, but there are several problems with this version:

1) It needs synchronize_kernel to be 100% correct, which was broken by preempt.
2) It sometimes crashes on x86, because I don't think I untwisted the boot process correctly.
3) It only supports x86.

Comments welcome!
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.