16M on 4.1bsd

[chris%umcp-cs%udel-relay at sri-unix.UUCP]

From:  Chris Torek <chris%umcp-cs at udel-relay>

(This may be of general interest...  I thought I probably should copy
 it to the Unix-Wizards list.)

 Date:     13 Sep 83 18:49:37 EDT  (Tue)
 From:     Chris Torek <chris at umcp-cs>
 Subject:  16M on 4.1bsd
 To:       negaard at aerospace

A quickie answer off the top of my head:  try increasing the space
reserved for the system page table map (called, I think, "Sysmap").
I just looked at machdep.c and locore.s -- the size is determined
by the #define'd constant SYSPTSIZE in ../h/vmparam.h (note the
comment about "this should be computed at boot time"!).  To map 16M
you need, I think, twice as many pt entries as they allocated.
(How about that, I was right, it's "Sysmap" and "Sysbase".)

The black book (or is it the red book?  Well, one of either the
Architecture Manual or the Hardware Handbook) has more info on
VM and pte allocation, if you need it.

Chris