Subject: Re: Experimental zero-copy for TCP and UDP transmit-side
To: Tomas Svensson <>
From: Sean Davis <>
List: current-users
Date: 05/10/2002 06:01:49
Weird, because things have been faster lately with lukemftpd. I wonder what
caused the speedup, or maybe windows is just being odd :)

On Fri, May 10, 2002 at 12:00:28PM +0200, Tomas Svensson wrote:
> Friday, May 10, 2002, 10:23:29 AM, you wrote:
> SD> Very nice!
> SD> I enabled it on my main NetBSD/i386 server, which has a thunderlan 10/100
> SD> adapter, and performance with FTP increased greatly. I typically saw 30-50mbit/s
> SD> when transferring large files from it via FTP, but since adding SOSEND_LOAN,
> SD> I've seen 90mbit/s more than once. I like it! :)
> SD> [note: using lukemftpd on the netbsd side, ws_ftp on the windows side. don't
> SD> know how accurate ws_ftp's transfer speed calculation is, but the improvement
> SD> has been signifigant.]
> lukemftpd can't utilize zero-copy by default? It's not using mmap()
> and it's overwriting it's buffer immediately after write() returns.
> I started to change ftpd into using mmap() but it made the kernel crash
> (only if I used SOSEND_LOAN).
> -Tomas

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