Re: rtVAX300 .. adding an CPU Type..

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

> [...] 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.

/~\ The ASCII                             Mouse
\ / Ribbon Campaign
 X  Against HTML                mouse%rodents-montreal.org@localhost
/ \ Email!           7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B