cvs commit: src/sys/kern sched_ule.c

[Jeff Roberson]

jeff        2008-04-17 09:56:01 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             sched_ule.c 
  Log:
   - Add a metric to describe how busy a processor has been over the last
     two ticks by counting the number of switches and the load when
     sched_clock() is called.
   - If the busy metric exceeds a threshold allow the idle thread to spin
     waiting for new work for a brief period to avoid using IPIs.  This
     reduces the cost on the sender and receiver as well as reducing wakeup
     latency considerably when it works.
  
  Sponsored by:   Nokia
  
  Revision  Changes    Path
  1.243     +71 -7     src/sys/kern/sched_ule.c