cvs commit: src/sys/kern kern_switch.c sched_4bsd.c

[Stephan Uphoff]

On Thu, 2005-06-09 at 21:44, Nate Lawson wrote:
> Stephan Uphoff wrote:
> > On Thu, 2005-06-09 at 19:25, John Baldwin wrote:
> >>On Jun 9, 2005, at 12:43 PM, Stephan Uphoff wrote:
> >>>ups         2005-06-09 19:43:08 UTC
> >>>
> >>>  FreeBSD src repository
> >>>
> >>>  Modified files:
> >>>    sys/kern             kern_switch.c sched_4bsd.c
> >>>  Log:
> >>>  Lots of whitespace cleanup.
> >>>  Fix for broken if condition.
> >>>
> >>>  Submitted by:   nate@
> >>
> >>What was broken about the if test?  The intention was that when 
> >>FULL_PREEMPTION was off, we only preempt if the destination thread is 
> >>an ithread or if the current thread is an idle priority thread. 
> > 
> > I was under the impression that we never preempt the idle thread but did
> > not investigate closer.
> > 
> > Is it save to preempt the idle thread on x86 when it does its ACPI
> > C-state magic?
> 
> I agree that the idle thread should be pre-empted before the Cx sleep.

Sorry - for the confusion. Interrupts are disabled before calling
acpi_cpu_idle so this should not be a problem.
I will restore the original test.

Thanks
Stephan