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Re: NetBSD in SIMH vax with 512 MB RAM



Den 2023-03-23 kl. 18:14, skrev Mouse:

Another way would be to limit the physical memory to 256M and add
support to not map all of physical memory for large-memory machines
as a compile-time option.
I'd say the rightest thing to do is compute - either mechanically or by
hand - what amount of physical memory would put SLR as close as
possible to 200000 without going over, then cap physical memory size at
that value (preferably with a message).
Yep, but that is not possible, since ~everything is possible to change dynamically and we cannot expand the SPT on-demand since it is located in physical memory. Having a SPT that can map all of S0 virtual memory would take 8MB of physical memory, which were too much of the available memory back when I wrote that code.  Maybe it isn't today when things are mostly run in simh and a different strategy should be used?

-- R


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