scheduler (sched_4bsd) questions

[Julian Elischer]

Stephan Uphoff wrote:

>>Maybe something brutal like:
>>	if ((curthread->td_ksegrp == kg) &&
>>	   (td->td_priority > curthread->td_priority))
>>		curthread->td_flags |= TDF_NEEDRESCHED;
>>
>>in setrunqueue for
>>the else case of "if (kg->kg_avail_opennings > 0)"
>>would do the trick (without preemption) for the easy but probably more
>>common cases?
>>
>>Maybe I can find some time next week to think about a clean
>>fix. I find it always helpful having a small task in mind while reading
>>source code.
> 
> 
> I wrote a fix that should cover all cases.
> However I would like to test it a little bit before posting the patch.
> Is there any multi-threaded kernel torture program that you can
> recommend?


Peter Holm (CC'd) has a really cool set of torture tests.
he has also seen all sorts of failures others have not (yet) triggered. :-)

I'm 'busy" for the next couple of weeks so you may want to communicate directly 
with him and see if you and he together can figure out some of the things he's
been seeing :-)

his tests are at:
http://www.holm.cc/stress/src/stress.tgz

> 
> Thanks
> 
> 	Stephan
>