> On Monday 01 December 2008 18:57:50 Chris Radek wrote: >> On Mon, Dec 01, 2008 at 05:46:48PM +0000, Leslie Newell wrote: >> > Is it possible to use EMC with multi-core processors? I see that by >> > default the kernel is compiled to only support one processor but what >> > would happen if SMP support was compiled in? Would RTAI choke? >> > >> > As multi-core processors become more prevalent, would it be practical >> > to >> > dedicate one core to the realtime stuff and let the other(s) do the >> > rest? It seems wasteful but I would have thought it would give very low >> > latency. >> >> I did this a while back on a dual P3 system. It gave excellent >> latency. Like you say, you can isolate a CPU so nothing but realtime >> tasks run on it. No special support is needed in EMC2; it is just a >> kernel and RTAI configuration issue. >> >> It was quite a job to get everything compiled right. I hope it's >> easier now but I wouldn't bet on it. > > Nice. What are the basic config settings you have to do? > How to bind rtai to a CPU? > when booting the linux kernel you use isolcpus (http://www.linuxtopia.org/online_books/linux_kernel/kernel_configuration/re46.html) Note: isolcpus is supposed to get deprecated in favour of another mechanism.
Once you've isolated linux from one core, you can run rtai specifying that core at startup (something like: "insmod rtai_hal.ko IsolCpusMask=2") Regards, Alex ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
