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

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

[M. Koehrer]

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

[Jan Kiszka]

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M. Koehrer wrote:
> Hi Jan,
> 
> I tried disabling SMP - but no success...

Means the problem persists under UP?

> 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?

nmi_watchdog=1, a kernel parameter. You should also find Linux related
messages regard the NMI watchdog in your log.

> 
> 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.

Well, I can understand stand you are looking for a stable version now.
But please also understand that we are highly interested in nailing down
this potential bug, specifically as Xenomai 2.3 with .19 support is
waiting at the door.

Jan


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

[Gilles Chanteperdrix]

M. Koehrer wrote:
> 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.

In order to get the NMI watchdog, you have to enable it on kernel
command line, passing nmi_watchdog=2 or nmi_watchdog=1. Read linux
Documentation/nmi_watchdog.txt for more details.

-- 
                                                 Gilles Chanteperdrix

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

[M. Koehrer]

O.k,

I tried once more with the  NMI watchdog stuff.
However, it looks as if I do not understand the NMI watchdog correctly...
I passed nmi_watchdog=1 as kernel parameter.
Now, the NMI watchdog seems to be o.k.
I have set the kernel parameter "NMI watchdog latency threshold (us)" to 1000000 (1 second).
Now I do a modprobe xeno_nucleus.
This is o.k.
Then I do a modprobe xeno_native.
This leads to a watchdog NMI on the console after 1s.
"NMI watchdog detected timer latency above 100000us"
CPU 1
EIP is at mwait_idle 0x23/0x37

When I compile the Xenomai functionality directly into the kernel (no modules), I never reach
the login prompt at my PC as the NMI watchdog from above came first...

Well, somehow the NMI stuff seems to work. However, I am not able to start my application
as my systems gets the NMI before I have the chance to start the application...
What is wrong here? I think, I miss one piece in the puzzle...

Thanks for any support on that strange behaviour.

Regards

Mathias



----- Original Nachricht ----
Von:     Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
An:      "M. Koehrer" <mathias_koehrer@domain.hid>
Datum:   18.12.2006 15:29
Betreff: Re: Aw: Re: [RTnet-users] [Xenomai-help] rtnet / Xenomai: Kernel
 2.6.19.1

> M. Koehrer wrote:
> > 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.
> 
> In order to get the NMI watchdog, you have to enable it on kernel
> command line, passing nmi_watchdog=2 or nmi_watchdog=1. Read linux
> Documentation/nmi_watchdog.txt for more details.
> 
> -- 
>                                                  Gilles Chanteperdrix
> 

-- 
Mathias Koehrer
mathias_koehrer@domain.hid


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ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT JETZT bei Arcor: günstig
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Re: Aw: Re: Aw: Re: [RTnet-users] [Xenomai-help] rtnet / Xenomai: Kernel

[Gilles Chanteperdrix]

M. Koehrer wrote:
> O.k,
> 
> I tried once more with the  NMI watchdog stuff.
> However, it looks as if I do not understand the NMI watchdog correctly...
> I passed nmi_watchdog=1 as kernel parameter.
> Now, the NMI watchdog seems to be o.k.
> I have set the kernel parameter "NMI watchdog latency threshold (us)" to 1000000 (1 second).
> Now I do a modprobe xeno_nucleus.
> This is o.k.
> Then I do a modprobe xeno_native.
> This leads to a watchdog NMI on the console after 1s.
> "NMI watchdog detected timer latency above 100000us"
> CPU 1
> EIP is at mwait_idle 0x23/0x37
> 
> When I compile the Xenomai functionality directly into the kernel (no modules), I never reach
> the login prompt at my PC as the NMI watchdog from above came first...
> 
> Well, somehow the NMI stuff seems to work. However, I am not able to start my application
> as my systems gets the NMI before I have the chance to start the application...
> What is wrong here? I think, I miss one piece in the puzzle...
> 
> Thanks for any support on that strange behaviour.

1 second is probably way to much and overflow a 32 bits value when
converted to a processor ticks count. The defaults of 100 us is more
reasonable.

-- 
                                                 Gilles Chanteperdrix