On Sunday, August 10, 2003, at 02:37  PM, Stephan Uphoff wrote:

> cpu_switch() running on CPU B tries to acquire the scheduler lock while
> blocking all interrupts.

sched_lock must be acquired while at splsched().  So, if you're not 
blocking all interrupts here, you must go to splsched() somehow.


>
> 	Stephan
>
>
> Index: locore.S
> ===================================================================
> RCS file: /cvsroot/src/sys/arch/i386/i386/locore.S,v
> retrieving revision 1.13
> diff -u -r1.13 locore.S
> --- locore.S    2003/08/08 20:14:06     1.13
> +++ locore.S    2003/08/10 21:20:40
> @@ -1794,7 +1794,8 @@
>         cli
>         cmpl    $0,_C_LABEL(sched_whichqs)
>         jz      idle_loop
> -idle_exit:
> +idle_exit:
> +       sti
>         movl    $IPL_HIGH,CPUVAR(ILEVEL)                # splhigh
>  #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
>         call    _C_LABEL(sched_lock_idle)
>
>
>
         -- Jason R. Thorpe <thorpej@wasabisystems.com>