cvs commit: src/sys/alpha/alpha interrupt.c

[John Baldwin]

jhb         2004/03/23 14:28:16 PST

  FreeBSD src repository

  Modified files:
    sys/alpha/alpha      interrupt.c 
  Log:
  Enable interrupt preemption on Alpha.  Previously, flipping this switch on
  caused hangs on SMP systems under load.  My theory was that an interrupted
  thread was migrating and returning to PAL on a different CPU and that that
  caused the hangs.  To prevent this, I used the recently added sched_pin()
  API to pin the interrupted thread to the CPU that received the interrupt
  across ithread_schedule() to prevent migration.  This seems to have fixed
  the hangs based on tests by several folks on the alpha@ list.
  
  Tested by:      wilko, tisco, several others on alpha@
  
  Revision  Changes    Path
  1.77      +10 -1     src/sys/alpha/alpha/interrupt.c