The problem is a socalled SMI (System Maintenance Interrupt) that causes the problem. A solution is to disable the SMI. From the instructions on linuxcnc wiki I prepared for making the module to fix the SMI. Then I found out that the required module rtai_smi.ko was compiled in the emc2 distribution. I just had to activate the module.

 

One single line should be added to the file /etc/emc2/rtapi.conf

 

#List of realtime kernel modules to be loaded

if [ "3" = "3" ] ; then \

MODULES="adeos rtai_hal rtai_ksched rtai_fifos rtai_shm rtai_sem rtai_math rtai_smi"

RTAI=3

MODPATH_adeos=

MODPATH_rtai_smi=/usr/realtime-$(uname -r)/modules/rtai_smi.ko

MODPATH_rtai_hal=/usr/realtime-$(uname -r)/modules/rtai_hal.ko

MODPATH_rtai_ksched=/usr/realtime-$(uname -r)/modules/rtai_ksched.ko

 

Added line is the line with rtai_smi !

 

 

latency-test shows good results after this modification and the error screens hasn't been seen since.

 

Laptop is an IBM T30 with 512MB ram and 10G disk. 
