From mboxrd@z Thu Jan  1 00:00:00 1970
Message-Id: <200110051918.f95JICT87292@ducky.net>
To: 9fans@cse.psu.edu
From: Mike Haertel <mike@ducky.net>
Subject: [9fans] how to install Plan 9 on a multiprocessor
Date: Fri,  5 Oct 2001 12:18:12 -0700
Topicbox-Message-UUID: ff33cc1a-eac9-11e9-9e20-41e7f4b1d025

Some time ago, I tried installing Plan 9 on two different
multiprocessors, a dual P-III 1GHz, and a quad P-II 333 Mhz.  It
didn't work on either.  Ok, I thought: it's flaky and only works
on exactly the hardware owned by Bell Labs.

Well, I was wrong.

The real problem is that the kernel you get when you install the
last full distribution (3/27/2001) has an interrupt handling bug
that was fixed in in the April 25th update.

But this doesn't help much when you are doing a fresh install--even
when you also install the patch, it only contains source code.

So the magic incantation was: install the 3/27 distribution, then
install all subsequent updates, then--while still running off the
boot floppy--rebuild the kernel from source, and make sure the new
kernel is the one that's installed.

Now it works fine on the quad P-II.  Haven't had a chance to try it
on the dual P-III yet.

It would be nice if someone would roll a new plan9.9gz that contained
at least this fix and some of the others, like the new Nvidia
drivers.  In fact, on the quad P-II I had trouble with the interrupt
handling bug even when it was running with just one processor
enabled.  It is easy to imagine someone casually giving the system
a try, running into all of these subsequently fixed bugs, and giving
up right away because it is "obviously too flaky" to use.