Subject: Re: [RT] [RFC] simple SMI detector
From: Jon Masters <jonathan@jonmasters.org>
To: Theodore Tso <tytso@mit.edu>
Cc: Sven-Thorsten Dietrich <sdietrich@novell.com>,
       Thomas Gleixner <tglx@linutronix.de>, Lee Revell <rlrevell@joe-job.com>,
       linux-rt-users@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
       williams <williams@redhat.com>,
       "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
In-Reply-To: <20090125040246.GE9216@mit.edu>
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Date: Sun, 25 Jan 2009 16:41:20 -0500
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On Sat, 2009-01-24 at 23:02 -0500, Theodore Tso wrote:

> I'm not sure exactly how one would do this certification, but I agree
> that some kind of "real-time ready" logo/certification program would
> make a huge amount of sense, with some standardized metrics of maximum
> time spent in an SMI routine, and under what circumstances (in some
> cases it occurs every 30-60 minutes; on other cases, only when the CPU
> is about to melt itself into slag, or when there are ECC errors, etc.)
> There is a huge difference between a system which stops the OS on all
> CPU's dead in its tracks for milliseconds once every 45 minutes,
> versus one which only triggers an SMI in extreme situations when the
> hardware is about to destroy itself.

I actually already talked to a certain industry group about a different
program but will mention this idea also - some kind of industry notion
of "real time platform" probably wouldn't be a bad idea. I'm not sure
what the vendors would say/think, but it's probably worth having the
discussion anyway. I think we're all right now having to do a lot of
legwork in testing/certifying that systems have acceptable latencies.

Jon.


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