From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <13426df10805271502s7e78ba0dw826dd2f6d982304c@mail.gmail.com>
Date: Tue, 27 May 2008 15:02:15 -0700
From: "ron minnich" <rminnich@gmail.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Subject: [9fans] A shot in the dark
Topicbox-Message-UUID: ad83b72c-ead3-11e9-9d60-3106f5b1d025

OK, this is a long shot, but i'm running out of ideas.

Long, long ago, at a Usenix, I saw a talk by some adventurous
australians (are there any other kind?). It was concerning some neat
hardware designed for kernel monitoring.

They had done a very neat hack. Basically, they modified the C
compiler so that, on function entry and exit, the code would emit a
16-bit quantity to the parallel port. They had some simple hardware to
grab the data.

WIth this, they were able to get some nice kernel performance numbers,
all for the (low at the time) cost of an outw to the parallel port.

OK, I have done some searching and can't find this. IIRC it was
pre-website usenix. I am going to UCB this week and may have time to
hunt it down in the paper archives, but ... just wondering ... anyone
else remember this?

thanks

ron