sparc64/94190: hw.physmem tunable does not work on sparc

[Kris Kennaway]

>Number:         94190
>Category:       sparc64
>Synopsis:       hw.physmem tunable does not work on sparc
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-sparc64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Mar 07 21:20:01 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Kris Kennaway
>Release:        FreeBSD 7.0-CURRENT sparc64
>Organization:
FreeBSD
>Environment:
FreeBSD/sparc64
>Description:

The hw.physmem tunable can no longer be used to limit the amount of
RAM used by FreeBSD (e.g. for the purposes of limiting dump size).
This was broken for a long time, but seemed to be fixed by r1.152 of
src/sys/sparc64/sparc64/pmap.c.  Now it doesn't work again (so either
it's broken again, or it never worked properly).

>How-To-Repeat:

On a system with e.g. 16GB of RAM, set hw.physmem="8g" in
/boot/loader.conf.

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: