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Date: Thu, 08 Nov 2007 23:02:53 -0800
From: Tim Kientzle <kientzle@freebsd.org>
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To: Dan Nelson <dnelson@allantgroup.com>
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Cc: freebsd-hackers@freebsd.org, Randall Hyde <randyhyde@earthlink.net>
Subject: Re: Some FreeBSD performance Issues
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Dan Nelson wrote:
> In the last episode (Nov 08), Randall Hyde said:
> 
>>It appears that character-at-a-time file I/O is *exceptionally* slow.
>>...  reasonable, though not stellar, performance under
>>Windows and Linux. However, with the port to FreeBSD I'm seeing a
>>three-orders-of-magnitude performance loss. ...
> 
> What timings does 
> "dd if=/usr/include/sys/socket.h of=/dev/null ibs=1 obs=64k" report? 
> It takes about .4 sec on my non-idle dual pIII-900 system.  Try
> truss'ing your program as it runs; maybe the program is doing some
> extra syscalls you aren't aware of?

You should also carefully do an strace or similar on
Windows and Linux as well.  You may find that you're
doing a system call per byte on FreeBSD but not on
those other systems.

Tim Kientzle