Hallo,

I have been testing quite a bit with large-memory systems here
(NetBSD/macppc), these turned out to be th facts:

a) The memory space addressable by NetBSD (RAM + VM) seems to be
   31 bit (or 32 bit signed, at your wish), that means that if
   you tough the magic limit of 2GB (total) you end up with the
   kernel thinking it has 0 bytes.

b) I have not seen yet a NetBSD/macpps system working with 1.5 GB
   of address space (however you compose it, with RAM and/or swap)
   and it just does not work.

c) You can have a machine run with 1GB but the number of problems
   (it boots on one machine, same disk ported to another G4 model
   with the same RAM configuration will panic at boot) and random
   crashes, never had the time to investigate with these deeply.

As of now I don't run any machine with more than 768 MB of address
space.... not with NetBSD at least.

It is quite a sin, since nowadays having gigabytes of physical memory
is absolutely reasonable and the limit imposed by 32bit platforms
begin to be quite severe, to further lower them...

Maybe some serious check on the VM system has to take place ?
Happy to contribute if I can (in the minimum case with tests...
ask me to test anything on any Apple hardware and I can grab it).

Regards,

Andrea

At 9:50 -0600 11/4/2002, Aaron Mildenstein wrote:
>My workaround?  I just disabled swap in /etc/fstab and restarted the box.
>I still have over 400MB of free RAM when I run top, but I no longer have
>"fork: Cannot allocate memory" messages.  Hope that helps you out!

> > From: Aaron Mildenstein <buh@mildenstein.net>
> > I am running NetBSD 1.5.2 on a Beige PowerMac G3 (OF 2.0.4) 266MHz with
>> 512M of RAM.  I have never dipped below 390M of free memory, and yet in my
> > daily cronjob email I see "fork: Cannot allocate memory" messages at the
> > point where it would fork the /etc/security script, and other such.  I've
> > tried recompiling the kernel, and tweaking memory setting to eradicate
>> these messages, but to no avail.  Can anyone give me an answer as to why
>> this message crops up?  Is it a bug that's been fixed in recent -current
>> snapshots?  It this related to the NEWPMAP thread I've seen going around?
>> This is my first "at bat" with NetBSD.  I've been a FreeBSD user and
>> SysAdmin for a long time now.  I'd love to put this Mac to good use, but
> > can't until I can resolve this strange issue.


-- 
Andrea Cocito
Director of the Bioinformatics Research Unit
Department of Experimental Oncology
European Institute of Oncology
Via Ripamonti 435, Milano - Italy
Tel. +39-02-57489857
Fax. +39-02-57489851