Updated preempt-kernel patches

[Robert Love]

Updated preempt-kernel patches for 2.4.10, 2.4.12, 2.4.13-pre1, and
(phew!) 2.4.12-ac1 are available at:

http://tech9.net/rml/linux

Note the patches for 2.4.10 are updated over previously releases.

These patches allow create a preemptible kernel -- increasing system
response time.  Everyone is encouraged to give it a whirl and report
back.

Major changes include code to prevent CPU changes on preempt (should
prevent a class of race conditions), an SMP compile fix, and various
cleanups.

Full change log:

20011011
- remove pgalloc.h preemption disable statements -- not
  needed with the new CPU switch prevention
- fix compile on SMP in some configurations (ac tree only)

20011005
- rearrange sched.c so we can patch cleanly against rtsched
  (or vice versa)

20011004
- prevent the case of preemption causing a CPU switch
  by locking tasks to the current CPU in preempt_schedule
- revert to _raw_spin_xxx from _spin_xxx since PPC uses
  that convention.

20011003
- push pcmcia-cs tools fix into their next release

20011001
- fix spin_lock_prefetch optimization causing (harmless)
  compile warnings

	Robert Love