From owner-freebsd-net  Wed Nov 29 22:17: 4 2000
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Date: Wed, 29 Nov 2000 23:16:53 -0700
From: "Kenneth D. Merry" <ken@kdm.org>
To: arch@FreeBSD.org
Cc: gallatin@FreeBSD.org
Subject: zero copy code review
Message-ID: <20001129231653.A1503@panzer.kdm.org>
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[ -net and -current BCCed for wider coverage, this is probably best
handled on -arch ]

I would like to request reviews of the zero copy sockets and NFS code I've
been posting about for months:

http://people.FreeBSD.org/~ken/zero_copy

There are diffs posted above against -current as of early November 28th,
along with a FAQ, and change log.

These diffs include changes in:

 - the socket code
 - NFS code
 - VM code
 - ti(4) driver
 - sendfile code

Much of the code was written by Drew Gallatin <gallatin@FreeBSD.org>, but I
wrote a lot of the ti(4) driver mods and cleaned things up a fair bit.

The code is stable, and I don't know of any bugs at the moment.  I have run
with it enabled on one of my main development boxes for months without any
problems.

The way things are currently configured, it is not turned on by default.
You need two kernel options and a sysctl to turn it on.  The zero copy NFS
code can be turned on with gdb, although it might be better to make that
into a sysctl.  (I haven't played with the zero copy NFS code much, Drew
has done much more with that.)

How to turn the code on is covered in the web page, above.

Anyway, I'd like to commit this code sometime next week, if no one comes up
with any issues or problems.

Comments, bug reports, etc., are welcome.

Thanks!

Ken
-- 
Kenneth Merry
ken@kdm.org


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