From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@coraid.com>
Date: Fri, 10 Jul 2009 09:54:40 -0400
To: 9fans@9fans.net
Message-ID: <233fc0081d92808d03186c4093fadfb6@coraid.com>
In-Reply-To: <8d11fee952ab7fc2b57d410bd848c1d3@quanstro.net>
References: <8d11fee952ab7fc2b57d410bd848c1d3@quanstro.net>
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Subject: Re: [9fans] Keyboard and Mouse
Topicbox-Message-UUID: 1a297122-ead5-11e9-9d60-3106f5b1d025

> > This problem is well known, and seems to be
> > caused by HyperThreading on some CPU.
> >
> > Try to add the following line to "plan9.ini":
> > *nomp=1
> >
> > It will solve this problem.
>
> hyperthreading?  that doesn't sound right.
>
> do you mean a bad mp interrupt table?

you can avoid ht by setting *ncpu=1 in your
plan9.ini without disabling mp interrupts.
so it should be easy to say definitivly which
one causes the problem.

as a further explainer, 8259 interrupts can't
work in an mp environment.  you need to
use either mp interrupts or msi interrupts.
since plan 9 doesn't implement msi, *nomp=1
implies that only one cpu may be activated.
so a uniprocessor may still use mp interrupts.

- erik