On 06/03/2017 03:36 AM, Gene Heskett wrote: >> 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.
Yes, isolcpus=X is the way to do that. However, doing so means that the kernel never schedules anything on the core automatically. You must set the thread/process affinity in the running code, using a syscall, to move a specific thread/process onto that isolated core. Otherwise, it will be idle all the time. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ 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
