On Sat, 13 Jul 1996, Warner Losh wrote:

> : spl is probably fundamentally wrong for SMP.  I haven't thought much
> : about what to use instead.
> 
> The Solbourne people might disagree with you.  As might the VMS
> Digitial people.  Both groups used a scheme where you would raise the
> spl *AND* grab access locks to data structures (I think the latter was

It's the quick and dirty route to getting an SMP version out the door
under budgetary or market timing constraints. 

To do it right, sections of code have to be rewritten to make the code as
parallel as possible. 

Caching also works very differently with multiple CPU's.