Johnny Billquist <bqt@Update.UU.SE> writes:

> And speaking of Unix. I suddenly can't remember for sure, but I think that
> the networking stuff runs in supervisor mode.

That's what 2.11BSD does, yes.

> One might ask why the supervisor mode even exist. The only point
> really is that this allows you a fast way to change your mappings,
> since you don't need to reload the MMU registers, and each mode has
> it's own stack pointer.

...and I've always assumed that this is the reason.

-tih
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