Date: Tue, 29 Jul 2003 17:19:51 +0100
From: Jamie Lokier <jamie@shareable.org>
To: Helge Hafting <helgehaf@aitel.hist.no>
Cc: linux-kernel@vger.kernel.org
Subject: Re: The well-factored 386
Message-ID: <20030729161951.GA15889@mail.jlokier.co.uk>
References: <03072809023201.00228@linux24> <20030728093245.60e46186.davem@redhat.com> <20030728194127.GA10673@mail.jlokier.co.uk> <20030729111423.GA5320@hh.idb.hist.no>
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Helge Hafting wrote:
> > The one thing that made it on-topic for me was his quiet suggestion
> > that "forreal" mode interrupts are faster, and that it might, perhaps,
> > be possible to modify a Linux kernel to run in that mode - to take
> > advantage of the faster interrupts.
> 
> That would have to be a kernel for very special use.  The "forreal"
> mode has protection turned off.  As far as I know, that
> means any user process can take over the cpu as if
> it was running in kernel mode.

There are quite a few embedded systems where that is ok, especially if
performance is improved.

Also, I am not sure whether paging still works in "forreal" mode.  If
it does, kernel memory could still be protected.  Not well enough for
security, but enough to protect against programming errors.

-- Jamie
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