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Date: Thu, 23 Jun 2005 01:57:20 +0200
From: Andrea Arcangeli <andrea@suse.de>
To: Karim Yaghmour <karim@opersys.com>
Cc: Ingo Molnar <mingo@elte.hu>, Bill Huey <bhuey@lnxw.com>,
       Kristian Benoit <kbenoit@opersys.com>, linux-kernel@vger.kernel.org,
       paulmck@us.ibm.com, tglx@linutronix.de, pmarques@grupopie.com,
       bruce@andrew.cmu.edu, nickpiggin@yahoo.com.au, ak@muc.de,
       sdietrich@mvista.com, dwalker@mvista.com, hch@infradead.org,
       akpm@osdl.org, rpm@xenomai.org
Subject: Re: PREEMPT_RT vs I-PIPE: the numbers, part 2
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On Wed, Jun 22, 2005 at 07:38:27PM -0400, Karim Yaghmour wrote:
> Bare in mind here that what we're trying to find out with such
> tests is what is the bare minimum cost of the proposed rt
> enhancements to Linux, and how well do these perform in their
> rt duties, the most basic of which being interrupt latency.

Agreed. I think it makes more sense to keep comparing it against the UP
kernel with preempt disabled, since most embedded devices aren't smp.

> To be honest, however, I have a very hard time, as a user, to
> convince myself that I should enable preempt_rt under any but
> the most dire situations given the results I now have in front

Same here.