Aw: Re: [RTnet-users] [Xenomai-help] rtnet / Xenomai: Kernel 2.6.19.1

["M. Koehrer" <mathias_koehrer@domain.hid>]

Hi Jan,

I tried disabling SMP - but no success...
Unfortuantely, the SMI watchdog does not work on my machine.
After booting the PC, dmesg shows me the line
Xenomai: NMI watchdog not available.

Is the NMI watchdog support somehow configurable or is this a real hardware issue?

For patching the kernel, I used the adeos-ipipe-2.6.19-i386-1.6-02.patch which is
part of Xenomai.

As I do not see an easy way to get the 2.6.19.* running,  I think, I will switch back to 
the latest 2.6.17.* kernel (2.6.17.14) which works fine.

Regards

Mathias
> > I have an issue with the latest Xenomai (svn #1962) and rtnet (svn #1095)
> versions
> > using kernel 2.6.19.1. The very same application worked fine on 2.6.17.7
> (same Xenomai/rtnet).
> 
> /Might/ be an issue of the still fresh 2.6.19 patch. You are using
> latest ipipe 1.6-02? Any difference with an earlier version of the
> patch? Is the IRQ routing identical for both 2.6.19 and .17?
> 
> > My application does the following steps in user space:
> > 1) I open one UDP socket to an embedded device.
> > 2) The timeout of the socket is set to 5 seconds.
> > 3) I send out one UDP message A via rt_dev_send() to the device.
> > 4) Then I wait for the response for A in rt_dev_recv()
> > 5) Directly after the return of rt_dev_recv() I send  message B via
> rt_dev_send()
> > 6) Then I wait for the response for B in rt_dev_recv()
> > Here my PC freezes. I am no longer able to access it, I have to press the
> reset button on the PC.
> > 
> > I have connected the PC and the embedded device with a hub. This allows me
> to monitor the network
> > traffic using a second PC. Ethereal shows me, that message B is sent to
> the embedded device
> > and the response of B is sent back to the PC.
> > 
> > Whenever I place a printf() directly after the rt_dev_recv() statements to
> see what happens,
> > everything works fine and the PC no longer freezes.
> 
> printf causes a mode switch and certainly some delay that may let the
> system avoid the race situation above.
> 
> > 
> > As mentioned above, when I use the very same application with 2.6.17.7
> (same Xenomai, rtnet version)
> > everything is perfect!
> > I have a Pentium 4 Dual core, SMP enabled.
> > 
> > Any idea on this strange behaviour?
> 
> Not directly.
> 
> OK, this is what you could try: Switch on the Xenomai watchdogs (soft
> and NMI). Check if the NMI watchdog is working: boot log messages, maybe
> even a test triggering via small /proc/xenomai/nmi_maxlat (we had
> problems with it already on some other user's box, so some confirmation
> the NMI works is useful). Then see if you system can at least issue some
> oops on lock-up. Attach a serial console to grab it.
> 
> Beyond this test, could you also try with CONFIG_SMP switched off?
> 
> Jan
> 
> 
>

-- 
Mathias Koehrer
mathias_koehrer@domain.hid


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