On Mon, 2011-05-16 at 11:01 -0500, Jon Elson wrote: > Kent A. Reed wrote: > > > > As for PREEMPT_RT, I have no idea whether it gives acceptable real-time > > performance, has an acceptable API, or is easy/hard to connect to EMC2 > > code. Perhaps some of the core developers can comment. > > > From reading the RTAI list, I think the answer is no. Prempt_RT is not > awful, but it seems to > give as much as 100 us jitter on machines that give 5 us jitter with > RTAI. This might barely be acceptable > on a servo machine, but would be a big problem on a system with software > step generation.
I think it depends on what preempt-rt kernel you are using and what other drivers you're running in the kernel. I once tried it and it ran at about 15-20 us jitter. So that's already usable for slow stepper systems. I don't know how recent rt development influenced this further. My last tests were 1.5 years ago. There were a lot of rt improvements in the meantime. -- Greetings Michael. ------------------------------------------------------------------------------ Achieve unprecedented app performance and reliability What every C/C++ and Fortran developer should know. Learn how Intel has extended the reach of its next-generation tools to help boost performance applications - inlcuding clusters. http://p.sf.net/sfu/intel-dev2devmay _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
