K 10
svn:author
V 5
luoqi
K 8
svn:date
V 27
1999-04-28T01:04:33.000000Z
K 7
svn:log
V 712
Enable vmspace sharing on SMP. Major changes are,
- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
  is added to point to per-cpu pages, per-cpu global variables are now
  accessed through this new selector (%fs). The selectors in gdt table are
  rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		John Dyson	<dyson@iquest.net>
		Julian Elischer	<julian@whistel.com>
		Bruce Evans	<bde@zeta.org.au>
		David Greenman	<dg@root.com>

END