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Re: rtVAX300 .. adding an CPU Type..
> [...] can at most handle (currently) processes of size 1GB.
> 1GB of user virtual memory takes 8MB kernel virtual memory which in
> turn takes 64K physical memory. If the indirection is missing then
> the page tables would take 8MB physical memory instead, or less, if
> the usrpt is shrunk in size.
For the KA620, then, you might want to either drastically reduce that
1GB or use some other technique, because 8M is half of a KA620's max
memory load. (Well, except for Qbus memory, which is less than
terribly useful both because it's comparatively slow and because it
uses up relatively scarce Qbus space - Q22 has only 4M of space, after
all. I suppose the kernel could bankswitch Qbus RAM, given RAM
hardware that supports that; it'd be faster than paging, but way slower
than the main 16M.)
Of course, that's assuming KA620 support is felt worth doing at all.
I'm not convinced it is worth doing.
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