On 10/12/2005 02:51 PM Heikki Lindholm wrote:
> Wolfgang Grandegger kirjoitti:
>> On 10/11/2005 05:11 PM Fillod Stephane wrote:
>>>Heikki Lindholm wrote:
>>>>Probably, but there are less than awesome 4xx boards around and I'd
>>>>guess they might even be more likely targets than G4 based machines,
>>>>example. Some tuning might be needed.
>>>How many people are using Xenomai (or Fusion) on 4xx ?
>>>What are their typical sched latency ?
>> Attached is the result of some latency measurements on the Ocotea eval
>> board. The AMCC 440 GX is already a fast 4xx processor. Unfortunately,
>> the linuxppc-2.6.10rc3 does not run on our Ebony board. Nevertheless,
>> it's difficult to provide a resonable default value. Why not simply
>> using 0 and it's then up to the user to provide an appropriate value
>> at configuration time?
> 0? No machine is that fast. For the 32-bit ppc it might be harder to
> provide a reasonable default, because of the broader scale of hardware,
> but I'd guess that < 100MHz targets prefer to use a dedicated RTOS
> instead of Xenomai. For the 64-bit targets, I didn't find slower than
There are a lot of 32 bit CPUs < 100 MHz running Linux and sometimes
they even need a realtime extension.
> 400 MHz machines and they were iSeries, which, I suppose, also aren't
> prime target for Xenomai. Regardless of what default value is used,
> there could be some examples provided by the config help to direct user
> to the right direction.
I fully agree.
> What's the problem with Ebonys? I remember running at least 2.6.9 on
> Ebonys (440GP) and Walnuts (405).
We have linux-2.4.14-rc3 running on all AMCC eval boards (see
http://www.denx.de). But the kernel supported by RTAI/Fusion,
linuxppc-2.6.10rc3, does not boot on Ebony. The main problem is the
missing support for U-Boot but there might be others. And it's simply
not worth the effort to port it, I think.