Re: ARM Linux Suitability for Real-time Application

[Andrew Lewis]

Russell King wrote:
> 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.

Thanks for the suggestions.  The FIQ solutions sounds like the one to 
use.  I'll probably do a little testing sometime in the next few weeks 
to determine the maximum loading I can place on the processor when 
running some of the other peripherals simultaneously.  If I have time 
I'll test the -RT patches as well and post up some numbers for this 
processor.

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