I have recently tested kernel 3.8.13-rt9 ( https://github.com/beagleboard/kernel/tree/3.8-rt) using git://git.kernel.org/pub/scm/linux/kernel/git/clrkwllms/rt-tests.git. I am using Ubuntu 12.04.4. The load was created using stress –cpu 1 which generates a cpu load of about 100%. I then used cyclictest:
root@ubuntu-armhf:/home/ubuntu/rt-tests# ./cyclictest -l1000000 -m -n -t1 -p99 -i400 -q # /dev/cpu_dma_latency set to 0us T: 0 ( 770) P:99 I:400 C:1000000 Min: 14 Act: 19 Avg: 18 Max: 132 uname -a reports: root@ubuntu-armhf:/home/ubuntu/rt-tests# uname -a Linux ubuntu-armhf 3.8.13-rt9-00899-g160e771 #1 SMP PREEMPT Wed Jun 19 10:49:36 CEST 2013 armv7l armv7l armv7l GNU/Linux I am absolutely surprised that the result is looking that good. Am Freitag, 21. Februar 2014 09:20:39 UTC+1 schrieb quik...@gmail.com: > > I am trying to figure out how to create a kernel for the BBB that supports > PREEMPT_RT. It's kind of strange that the BBB's default kernel does not > even have PREEMPT activated. Such a board doesn't fit to many embedded > applications where we need at least some kind of determinism. It is even > worse, that nobody seems to care about this problem. Contrary to that, the > Raspberry PI's standard kernel has PREEMPT activacted from the very > beginning. > > I have tested Robert Nelsons kernel 3.8.13-r9 ( > https://github.com/beagleboard/kernel/tree/3.8-rt). It does not have > PREEMPT_RT activated by default. When doing so, it does not boot. But > activating PREEMPT does work. However, development of this branch has > stopped several months ago. The official source for RT Linux (3.8.13) has > evolved since then. Meanwhile there's an rt17 patch set ( > https://www.kernel.org/pub/linux/kernel/projects/rt/3.8/). Did anybody > give this a try? Does it work with the BBB? > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
