IsolCpusMask Parameter

I downloaded and compiled the linuxcnc with newest rtai 4.0-test2. There is written they aim at better cpu isolation which seems a good idea. I have 2 core processor and isolcpus=1 parameter at boot improved the jitter a lot. There is also written to use IsolCpusMask for rtai_hal.ko module to achieve a better isolation. Linuxcnc rtapi uses the latest core in row as default. When I put IsolCpusMask=0x2 got the biggest jitter I've ever seen and then kernel fault. I don't know how exactly the mask should work or look like. I tried a few different masks with the same result. I don't know whether linuxcnc's rtapi can use this feature. Have someone tried to use the mask?

I have never tried using it, but have read some stuff about problems with it.

There was a patch which needed editing to suit architecture, but it is unclear if this became part of the RTAI sources

mail.rtai.org/pipermail/rtai/2013-October/025996.html

regards

I removed from rtapi.conf rtai_hal module then loaded it manually with IsolCpusMask=0x2 afterwards run latency test and got the same latency as without the parameter. Latency didn't change that much when you moved mouse or window it was more stable but higher from the beginning. cat /sys/modules/rtai_hal/parameters/IsolCpusMask gave 2 so the parameter passed. I expected more or doing something wrong. I haven't test it further. I should know much more about rtapi itselt.