[movitz-devel] OS decisions

Frode V. Fjeld frodef at cs.uit.no
Mon Jun 15 10:01:30 UTC 2009


Brian Makin <merimus at gmail.com> writes:

> Process isolation isn't quite as important when you can't write into
> random memory locations so easily.  If you have one lisp process
> running and I have another... how can I do something bad to you?

It boils down to what is your design goals, doesn't it? Thinking
historically about this, I believe that memory protection (or even
multi-user systems in general) came about because machines were so
huge and costly that sharing them between people (and even
organizations) was inevitable. But this pattern is very nearly
inverted now, in that each person now has (exclusive) access to
several machines.

That's not to say that hw protection isn't nice to have (and for some
applications even necessary), but remember also that there tends to an
inherent cost in terms of performance, system/code/programming
complexity, and general barriers to information flow.

So perhaps it would be more beneficial to focus on removing the
communication barriers between machines than how to add barriers
inside them? (Not to imply that these are conflicting desing goals,
other than wrt. time and effort.)

-- 
Frode V. Fjeld





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