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Re: Reviving SA: what is up with preempt() generating BLOCKED upcalls?



On Sun, May 11, 2008 at 12:35:23AM -0700, Matt Thomas wrote:
> 
> On May 10, 2008, at 9:40 PM, Bill Stouder-Studenmund wrote:
> 
> >As part of reviving SA, I'm re-adding all of the kernel  
> >infrastructure we
> >ripped out.
> >
> >In doing this, I looked at re-adding the preempt(int more) code we  
> >had.
> >However, I have serious questions about it. Like why do it?

[snip]

> You went from LSONPROC to LSRUN and that's shouldn't cause an BLOCKED  
> upcall.
> I think a BLOCKED upcall should be sent iff the state changed to  
> LSSLEEP.
> I also think if a change to LSSTOP or LSSUSPENDED happens an upcall  
> should
> not be sent since an external party want the lwp/proc to stop  
> execution and
> switching to a new one to continue execution just seems wrong.

Ok. Sounds good. So I wasn't totally misunderstanding it. :-)

Take care,

Bill

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