From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Daniel Walker <dwalker@mvista.com>
Cc: "Eugeny S. Mints" <emints@ru.mvista.com>,
Andrew Lewis <andrew-lewis@netspace.net.au>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>
Subject: Re: ARM Linux Suitability for Real-time Application
Date: Wed, 22 Jun 2005 18:22:50 +0100 [thread overview]
Message-ID: <20050622182250.A13976@flint.arm.linux.org.uk> (raw)
In-Reply-To: <Pine.LNX.4.10.10506220951190.455-100000@godzilla.mvista.com>; from dwalker@mvista.com on Wed, Jun 22, 2005 at 09:52:40AM -0700
On Wed, Jun 22, 2005 at 09:52:40AM -0700, Daniel Walker wrote:
> On Wed, 22 Jun 2005, Russell King wrote:
> > If you're just after some background process to run off interrupts with
> > minimal interrupt latency, the good news is that you don't have to modify
> > the kernel on ARM, and you certainly don't need any RT patches.
> >
> > If you use the FIQ, then your FIQ latency will be the time it takes the
> > CPU to enter your FIQ function. Since the kernel _never_ disables FIQs
> > in any way, FIQs have ultimate priority over everything else in the
> > system.
> >
>
> Aren't FIQ's only on some ARM's ?
Yes, but please read the original mail. I think you'll find my reply
is completely relevant to the question being posed, which was based
upon the AT91RM9200 SoC.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
next prev parent reply other threads:[~2005-06-22 17:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <42B8F6FB.2090203@netspace.net.au>
2005-06-22 8:55 ` ARM Linux Suitability for Real-time Application Eugeny S. Mints
2005-06-22 9:02 ` Russell King
2005-06-22 16:52 ` Daniel Walker
2005-06-22 17:22 ` Russell King [this message]
2005-06-23 3:44 ` Andrew Lewis
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