On Friday 02 June 2017 19:59:52 Bertho Stultiens wrote: > On 06/03/2017 01:08 AM, Gene Heskett wrote: > >>> 5mv? 4 amp box, haven't had a problem. > >> > >> And you do not see any red led on the pi blink then? > >> If yes, then you man need to add decoupling. > > > > Solid as a rock. > > That should be fine then. > > > Something different: > I see that the hm2_rpspi module is added to the servo-thread. I am > wondering if the control-loop will be more stable if one of the ARM > cores is isolated and assigned specifically to the servo-thread. > > I do not know the rtapi internals too well, so I'm wondering if CPU > affinity has been implemented in the code. For the Pi, it would > probably be a real-time advantage to have the servo-thread isolated on > one core and have the core for itself the whole time. > > Has anybody done an implementation of affinity in linuxcnc already? If > yes, how is it setup?
On the x86 stuff, in years past, we used "isolcpus"=3 (or whatever was the last core) as a kernel argument at kernel load time. On x86 stuff the cpu you have isolated is found and used automatically, however the use cannot be detected by the various cpu monitoring utilities such as htop. I had originally set that up to reserve core 3, on the 4 core pi, and on core 3 of the athlons I don't know who corrected me, but it was said that was no longer a useful item, so I took it back out of /boot/cmdline.txt and out of some of the x86 machines too, but I see its still in as an =1 on the two atom boards out in the shop. The one I removed it from hasn't indicated any unhappiness with that turn of events. Perhaps Sebastian or someone more familiar with it can shine a light on us here? As in has it been deprecated on all arches. I still have 2 D525MW's with it in effect. And htop cannot see any usage of cpu-1 on either of those 2 boxes. Cheers Bertho, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
