On 06/23/2014 01:09 PM, Gene Heskett wrote: > On Monday 23 June 2014 13:49:51 Bari did opine > And Gene did reply: > > >From the resident old fart :) > >> Just posting this info since this gets asked about often in IRC >> >> For RTAI to work with more recent kernels than 3.4 with Linuxcnc: >> >> 1) fix the scheduler in RTAI > > URL for that patch?
There is no patch yet. It has to get fixed with a patch. > >> 2) math support in kernel kconfig has changed and no options seem to >> work with Linuxcnc > Are you saying that forcing the math to be done by LCNC by leaving out any > fast math in the kernel is the only way that works? Or that nothing newer > than 3.4 works? Sorry to clarify: the Kconfig for RTAI (not the kernel) in regards to math support is broken, no option seems to work with Linuxcnc. Ever since newlib and glibc math options were added to Kconfig it stopped working with Linuxcnc. >> 3) Linuxcnc needs to fix /proc in order for any 3.10 or newer RTAI >> kernels to work > URL for that patch? Needs to be written. >> One workaround for the broken scheduler is with isocpu= you need to >> leave the last cpu core out of the list. For example isolcpus=1,2,3 for >> a 4 core and it should work or a single core cpu should work fine. >> > This seems backwards from what I've been told ever since the isolcpus > thing became available. Its my understanding that if I have isolcpus=1 in > the kernel command line of the grub file on my 2 core atom boards, with > hyperthreading turned off as its a huge time killer, then LCNC sees it and > runs the base_thread stuff on cpu1, and the rest of it on cpu0. And > everything else I run (firefox, konversation, gedit etc) can only see > cpu0. And the system runs well even when there is network traffic. > > Yes, it's backwards. That is the problem with RTAI. A comit was pushed to the RTAI tree a few months ago that broke the way isolcpus works. This is yet to be fixed. ------------------------------------------------------------------------------ HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions Find What Matters Most in Your Big Data with HPCC Systems Open Source. Fast. Scalable. Simple. Ideal for Dirty Data. Leverages Graph Analysis for Fast Processing & Easy Data Exploration http://p.sf.net/sfu/hpccsystems _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
