2.6.2 unexpected realtime error

I just did a fresh install from the live cd, just to launch lcnc , I picked a stepper config and got "unexpected realtime delay".
I ran dmesg and got this

[ 67.587984] In recent history there were
[ 67.587985] 2006052, 2007277, 2004913, 2012838, and 2005714
[ 67.587987] elapsed clocks between calls to the motion controller.
[ 67.587992] This time, there were 2608713 which is so anomalously
[ 67.587999] large that it probably signifies a problem with your
[ 67.588000] realtime configuration. For the rest of this run of
[ 67.588001] EMC, this message will be suppressed.
[ 67.588002]
[ 80.096901] RTAI[math]: unloaded.
[ 80.099564] SCHED releases registered named ALIEN PEDV$D
[ 80.115222] RTAI[malloc]: unloaded.
[ 80.212055] RTAI[sched]: unloaded (forced hard/soft/hard transitions: traps 0, syscalls 0).
[ 80.222464] I-pipe: head domain RTAI unregistered.
[ 80.222480] RTAI[hal]: unmounted.


I run servo's and mesa gear. What does this mean? max jitter on the servo thread is 9938 and on the base thread 11251. The computer is a amd 2g dual core asus m2n68 mb, and has run lcnc fine with previous versions. Thanks.

My system does that too.
Once in a while there is a small spike in the latency that is not large enough to affect LinuxCNC operation but it triggers the 'unexpected realtime delay' error. Like you, I am unable to catch that spike with the latency test, but I am able to catch it from within LinuxCNC.

See my topic here: www.linuxcnc.org/index.php/english/forum...-while-running#47049

You should investigate this though, and not just ignore it.

.........I picked a stepper config and got "unexpected realtime delay"

Are we talking a sim config?

They don't have a base thread and really don't prove anything.

As DaBit says there are very often one-off latency hits, usually when first loading Axis, possibly a combination of openGL rendering, plus disk access at the same time.

Do you get any warnings when running your machine config? That is all that matters.

regards

The stepper config is for an inch sherline, I picked it because it does to require any special hardware to load. I also picked the gmoccapy sim. When either of them load up , I get the error and sometimes an error about task one. I can clear them, but from time to time they pop back up. The same errors pop up on both of the hard drives , so I don't think it is a loading problem. I've run every version of EMC on this computer since 2.4 and it been problem free . Could this be a conflict with the Nivida video driver?

Hi

The same errors pop up on both of the hard drives , so I don't think it is a loading problem.

I wasn't suggesting it was due to disk access per se, just that it is a factor in latency spikes just as Axis loads.
In the same way you can see a spike when starting Firefox, but if you close it and re-open, there is no spike because it is cached in memory so no disk access and less system
strain all round

Could this be a conflict with the Nivida video driver?

It certainly could. The nvidia-glx driver notoriously does not play nicely with openGL.

I have a nvidia GT650 with 2GB GPU on this machine and I used to run this partition with the proprietary driver installed.
It would give a realtime warning every time I ran a sim.
It did not matter, because it is not connected to anything and I only run sims on it.

When I re-installed on this partition to purge some library version problems I was having, I stayed with the nouveau driver.
Even though I am running a rt-prempt kernel, which is much higher latency than rtai, I don't get the warnings any more.

I would not consider using a proprietary driver on a workshop machine, there is no need for it, the open source one can handle anything required of it in those circumstances.

Only if doing heavy CAD work, would I advocate using the increased acceleration and rendering power it brings.
(or gaming, which may be more important )

regards

Arceye,

Thanks for the insight. I'll load a real config on it and put it in a machine and see what happens. On another thread, I was battling getting a surfboard design program running, I loaded the java runtime environment and it works. Again thank you for your help on both issues.