From owner-freebsd-hackers  Wed Jan 14 21:09:25 1998
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To: Kachun Lee <kachun@pathlink.com>
cc: freebsd-hackers@FreeBSD.ORG
Subject: Re: 2.2-STABLE with 512M RAM 
In-reply-to: Your message of "Wed, 14 Jan 1998 13:19:42 PST."
             <3.0.1.32.19980114131942.00763f28@rr.pathlink.com> 
From: David Greenman <dg@root.com>
Reply-To: dg@root.com
Date: Wed, 14 Jan 1998 21:12:33 -0800
Sender: owner-freebsd-hackers@FreeBSD.ORG
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>I upgraded one of PPro FreeBSD 2.2-STABLE to 512M RAM. I recompile the
>kernel with MAXMEM=512*1024. The system came up and ran without problem.
>Also, 'top' showed all the memory was being used.
>
>I was going to apply the patch that Mr. Greenman posted about a year ago.
>The patch calls for increase some kernel parameters and require a 'make
>world'. I was wondering if that is still necessary. I prefer not to have to
>copy a separate source tree to do the 'make world'.
>
>If my memory serve me correctly, I remember that patch will make FreeBSD
>not BSDI compatible. Is this the only 'negative' about applying the patch?
>If I do not care about BSDI compatible, can I run the same kernel with our
>other non 512M systems?

   The answer to these last two questions is "yes".

   The patch is meant to increase the size of the kernel virtual address
space. This is necessary on "large" systems that have a large number of
processes and/or network connections (which consumes a large amount of
kernel virtual memory). If your system isn't "large" and just happens to
have a lot of physical memory, then you probably don't need to worry about
this.

-DG

David Greenman
Core-team/Principal Architect, The FreeBSD Project