Re: [9fans] Virtual memory & paging

["david presotto" <presotto@closedmind.org>]

Actually, I'ld be seriously worried about our ability to
add DLL support without major bugs.  It adds a lot
of complexity that spans the VM model, security,
and compilers.  A lot of Plan 9's speed and usefulness
arises from its simplicity and this would be a major step in
away from that, not that we haven't been whores 
before.

A major drawback right now is that, unless we change
our MMU handling in a drastic way,
we have to run the shared library at the same addresses
in all programs.   Might be a bit of a problem (unless we
go to 64 bit addressing).  The current MMU
model with its lazy evaluation and no need for a
intermachine shootdown is quite elegant and I'm not sanguine
to lose it just for DLL's.

As Geoff states, we don't seem to be losing out by not
having them, vis a vis memory size.  Some things would
be more efficiently done with a shared library, shared
databases for example.  I'm just not yet prepared to
pay the price in increased complexity.  Others may be.