jake a9f4853a90 Implement preemptive scheduling of hardware interrupt threads.
- If possible, context switch to the thread directly in sched_ithd(),
  rather than triggering a delayed ast reschedule.

- Disable interrupts while restoring fpu state in the trap handler,
  in order to ensure that we are not preempted in the middle, which
  could cause migration to another cpu.

Reviewed by:	peter
Tested by:	peter (alpha)
2001-02-01 03:34:20 +00:00
..
2001-01-24 10:27:11 +00:00
2000-11-30 18:52:32 +00:00