Increase kernel VA from 256Mb to 512Mb by shifting the segment used

for user copyinout down to 12, and keeping segments 13/14 for
kernel VA.

It would be nice to have more available, but segments lower than
this are reserved for either memory or 1:1 mapped device i/o,
and seg 15 is OpenFirmware ROM. Also, the effort to keep OpenFirmware
available for callbacks limits the use of VA-mapped segments.
Fortunately UMA_MD_SMALL_ALLOC takes away a lot of VM pressure.

Obtained from:  NetBSD

0 files changed, 0 insertions, 0 deletions