2.7.5 becomes unresponsive

Hi
I upgraded to 2.7.5 from 2.7.4 a few days ago and now have a issue that when I pause the process or stop mid process, Axis be comes unresponsive. In other words I am not able to toggle the machine power nor does the emergency stop button operate. The only option is to kill the process and restart the application. No other changes or updates in Linux since the upgrade. Any thoughts or suggestions?

Linux
3.4-9-rtai-686-pae
#1 SMP PREEMPT Debian 3.4.55-4linuxcnc

Architecture: i686
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 2
On-line CPU(s) list: 0,1
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 23
Stepping: 10
CPU MHz: 3324.906
BogoMIPS: 6649.81
Virtualization: VT-x
L1d cache: 32K
L1i cache: 32K
L2 cache: 6144K

I am unable to reproduce this problem.

I installed LinuxCNC using our Wheezy install iso, upgraded everything (so I got LinuxCNC 2.7.5), and rebooted. I ran LinuxCNC and chose the sim/axis/axis config, F1 to come out of E-stop, F2 to turn the machine on, Home All, then clicked the Run button. The program started and once it was moving I pushed the Pause button. The machine paused as expected. Clicking Pause again re-started it from where it had stopped, as expected. I also tried the Pause/Resume keyboard shortcuts and that all worked.

Can you try the sim/axis/axis config and see if that one works for you? If that one works right, it might be some interaction between the LinuxCNC 2.7.4 -> 2.7.5 upgrade and your particular configuration, or your G-code program, so please post those.

Hi,
The sim you suggested worked fine which caused me to dig a little deeper. It looks like I may have had a task running in the background that caused a real time jitter issue. I've retried with all non linux cnc tasks closed and 2.7.5 appears to be ok. I'll monitor the situation and repost if the problem reoccurs.
Thank you for your help.
Mike

Background tasks shouldn't be able to cause hangs or crashes. I'm still worried about this issue. Let me know how things go!

So here was the situation when 2.7.5 became unresponsive today. I was v carving when the material started to move so I pressed F2 to stop and then raised the z axis to realign the material. While raising the z axis I hit the limit switch and of course got the appropriate message and axis shut off. After releasing the z axis my manually (mechanically) bringing it off the switch,and LinuxCNC is still off, I could not restart, reload or even exit 2.7.5. I had to force kill all apps in linux in order to restart 2.7.5. I've had this situation with exceeding a limit switch in 2.7.4 and am usually able to use the override limits option to bring the axis back into play and continue on with the cut.
Thoughts?

I've seen this bug to.

Thanks for the bug reports, I appreciate the feedback.

I believe this bug has been fixed in the 2.7 branch as of v2.7.5-31-g1407654, to be released as 2.7.6 soon.

In the meanwhile it's available from the buildbot here: buildbot.linuxcnc.org/

Next time that happens, disconnect the paraport ( if using one ). If Linuxcnc works after disconnect ( most probably wont be usable, but it should at least be responsive), you have a grounding problem or bad interference between the machine and computer, mostly caused by bad power supplies.
Also start a terminal and type "sudo top", look for what is using high amounts of processor time.
If other software hangs at random, check the bios for "DMA enable" it should be on, if you're getting that only with Lcnc, don't bother with it.
Regards,
Tom

tommylight wrote: Next time that happens, disconnect the paraport ( if using one ). If Linuxcnc works after disconnect ( most probably wont be usable, but it should at least be responsive), you have a grounding problem or bad interference between the machine and computer, mostly caused by bad power supplies.
Also start a terminal and type "sudo top", look for what is using high amounts of processor time.
If other software hangs at random, check the bios for "DMA enable" it should be on, if you're getting that only with Lcnc, don't bother with it.
Regards,
Tom

Tom,
This is/was a bug when you hit the limit switch.

JT

Ooops, sorry for that, i had a similar problem, in one of the machines i was servicing, it would become unusable slow when a limit switch was triggered, but as soon as i removed the paraport connector, it would continue running normally, but i had to restart Linuxcnc. Turned out the cheap BOB was causing that when used with a cheap power supply, so i powered it from the usb port and it did not have that problem ever again, for nearly 3 years and running.
Regards,
Tom