On Sat, 7 Jan 2006, Nathan J. Williams wrote:
> In a hypothetical future where multiple CPUs may be in the kernel
> and/or in interrupt code, it's not; you then need to protect from
> the bottom half (interrupts) on your CPU, and from both halves on all
> other CPUs. The most conventional way to do this looks like:
>
> Top half:
> splfoo()
> simplelock();
> ...
> simpleunlock();
> splx();
>
> Bottom half:
> [already at splfoo]
> simplelock();
> ...
> simpleunlock();

I think I understand what the SPL levels do for UP systems now.
In the future, would we get rid of them completely, or continue having 
them in effect for UP systems, while MP operation with proper locking?


   - Hubert