Re: [Xenomai-help] Running xeno-test

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Martin Shepherd wrote:
> On Sun, 12 Apr 2009, Gilles Chanteperdrix wrote:
>> Martin Shepherd wrote:
>>> On Sun, 12 Apr 2009, Gilles Chanteperdrix wrote:
>>>> ...
>>>> Could you tell us the versions of Linux and Xenomai you are using and
>>>> post your .config ?
>>> I am using Xenomai 2.4.7, with Linux kernel 2.6.28.7, under Ubuntu 8.10.
>>>
>>> The following are the contents of the linux-2.6.28.7/.config file:
>> Ok. You seem to have avoided the usual pitfalls, however you really have
>> a lot of options enabled.
> 
> Yes, I started from the config that came with Ubuntu, which has lots
> of things turned on. However most of them are modules for drivers that
> will never be loaded.

No, there are also options which I would not recommend to turn on, such
as syscall auditing and the like.

> 
>> The symptoms of your problem really look like
>> a bug which I had and turned out to be a NO_HZ problem. So, maybe you
>> could try and disable CONFIG_NO_HZ ? You can also try to enable
>> Xenomai's NMI watchdog, which will fire if a timer overrun occur.
> 
> Correct me if I am wrong, but turning on the NMI watchdog appears to
> be contingent on having local APIC, which the processor that I am
> using (an ancient AMD Athlon), doesn't seem to have.

Last time I used an Athlon, it had a local APIC and IO-APIC. Only, the
Linux kernel disables them by default, so, you have to pass a special
option for them to be enabled (see TROUBLESHOOTING). The IO-APIC is
buggy and caused hard lockups, but the local APIC seemed to run fine.

> 
> I have tried disabling CONFIG_NO_HZ (by disabling Tickless System in
> "make menuconfig"), but this didn't change the symptoms.
> 
> It turns out that just running "dd if=/dev/zero of=/dev/null" on its
> own, without running xeno-test, hangs the computer after a random
> interval of a few seconds to a minute or so. At that point, the only
> thing that wakes it up for a few more seconds, is to hit a key on the
> keyboard of the computer, or move the mouse, and after a few times of
> doing this, the computer locks up hard and has to be rebooted. I have
> verified that this doesn't happen if I boot into Ubuntu with the
> 2.6.27-11 kernel that came with it.

Ok. Could you try a kernel without Xenomai but only with the Adeos
Interrupt pipeline enabled ?

-- 
					    Gilles.