Bug 29679

Summary:	FreeBSD and 4GB of ram not working
Product:	Base System	Reporter:	sagi <sagi>
Component:	i386	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	4.3-STABLE
Hardware:	Any
OS:	Any

Description sagi 2001-08-13 18:50:02 UTC

This problem has been tested on 2 machines:
1 is a DELL 6450 PowerEdge, with 4GB of memory (16 256mb dimms) 2 700 
Xeons processors.
a Intel board (SRKA4) with 4GB of memory (4 512mb dimms) and 4 700 Xeons 
processors.
I'm unable to get FreeBSD to work with 4GB of memory at all. 2GB works 
fine. When booting off a 4.3-release CD, after the kernel finishes loading 
and before  /stand/sysinstall starts i get:
swap_pager_swap == NULL and it crashes.
The intel machine is fully functional with the 2GB. When bringing it to 
4GB the error persists, right before it goes to mount the drives. I've 
attempted to remove the swap area from /etc/fstab and  not use swap at 
all. Please let me know if this issue has been resolved, and if so what is 
the work around.

When trying to install on 4.1.1 it traps immediatly (trap 12?).

Fix: 

I've heard it will work on 3.5. However I would like to use 4.x
How-To-Repeat: 	Attempt to use FreeBSD on a machine with 4GB of memory.

Comment 1 hiten pandya 2002-01-02 16:54:41 UTC

hi,

This issue has been discussed on the FreeBSD-Hackers mailing list, and
possible
fixes have been provided by various developers according to their
situations with
4GB of RAM.  The solution was discussed by Terry Lambert on the -hackers
list.

The specific thread to search for would be: 4G phisical memory kernel
trap

The reason is due to the limitations imposed in
src/sys/i386/i386/machdep.c, which
can be changed.  I am giving a short guideline on how to acomplish this:

1) Try changing the KVA space in the src/sys/i386/i386/machdep.c, and
recompile the
kernel.

2) If that doesn't work, it could be that you are running out of page
table pages
(originially pointed out by Tim Wiess <twiess@ahaza.com>).  The issue
can be
resolved by changing the NKPT #define in src/sys/i386/include/pmap.h to
64 and
the KVA_PAGES #define to a multiple of 4 (default value is 256).

This should resolve the issue.  If there are no further more problems,
then this
PR can be gracefully closed.

regards,

 - Hiten
 - <hiten@uk.FreeBSD.org>
-- 
1024 45:a5:9c:f2:fb:07:da:70:18:02:0b:f3:63:f1:7a:a6 hitenp@hpdi.ath.cx

Comment 2 ashp freebsd_committer

2002-01-18 03:00:34 UTC

State Changed
From-To: open->closed

Workarounds were listed in the PR, and are available in mailing list 
archives for those interested.