Re: Text widget dying

On Thu, 04 May 2000 19:54:09 MDT, Shippy! <>  said:
> Ok, I've tried it on yet another machine and
> I'm having the same problems. So now I have
> two machines each where it does and does
> not work. The only thing I can see that the
> non-working machines have in common is that
> they have SMP kernels. Is there anything special
> you have to do for SMP kernels?

Quite often, an SMP system reveals thread race conditions that
were never exposed on a single-cpu box.  The canonical example
is that on a 1-CPU box you may never notice that you forgot to
put a mutex around a routine that walks across a linked list, 
because you always do the walk in one timeslice, which gave
you a fake mutex.  On the SMP box, the OTHER cpu can be
walking the same list at the same time.  Whoops.

No, I haven't looked at the actual code, I've just spent 20 years
getting bit every so often by this class of bug. ;)

				Valdis Kletnieks
				Operating Systems Analyst
				Virginia Tech

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