From owner-freebsd-questions  Tue Oct  7 07:54:11 1997
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To: "Evan Champion" <evanc@synapse.net>
cc: freebsd-questions@FreeBSD.ORG
Subject: Re: Version with good mmap()? 
In-reply-to: Your message of "Tue, 07 Oct 1997 08:45:09 EDT."
             <01bcd31e$d89a4600$513654c7@cello.synapse.net> 
From: David Greenman <dg@root.com>
Reply-To: dg@root.com
Date: Tue, 07 Oct 1997 07:56:00 -0700
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>Does 2.2.1 or 2.2.5-BETA have a good mmap() (ie: fully functional, good
>performance) or if not does 3.0-current?

   The version in 2.2.x and 3.x should be fully functional - I don't know of
any problems with it.

>I seem to recall reading at some point that the mmap() in earlier releases
>wasn't quite up to scratch, but I can't remember which version was
>recommended.  I'm moving a server to FreeBSD which has a very heavy
>dependence on very large size/quantity mmap()'s.

   The only problem had to do with syncing modified information back to the
file, but I haven't heard of any problems with this in a long time.

>Also, does FreeBSD's mmap() require swap to back up the maps?

   For mapped files, no. The data is backed by the file.

-DG

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