Thanks for you tips. I am using a minimal Ubuntu system without a full desktop that is based on http://www.armhf.com/index.php/boards/beaglebone-black/#precise. I used apt-get to update the system. The integrated eMMC and HDMI are deactivated.
To create a network stress I used Ubuntu's iperf in server mode from another ssh shell while running stress and cyclictest at the same time. The transfer rate to another Ubuntu box reached 94.7 MBit/s and > 100MB were copied. The latency numbers did not change. Am Mittwoch, 26. Februar 2014 16:58:31 UTC+1 schrieb Charles Steinkuehler: > > Xenomai includes a "dohell" script that can generate disk and network > load. You can always just "dd" to a file for a while. > > If you're running a Debian/Ubuntu based system, I've found that running > "aptitude upgrade" if you have a few dated packages can be a major > stress to the system. That gets you both network and disk load, and not > so long ago had a decent chance of wedging the eMMC kernel driver (even > without the Xenomai patches that 'tickled' the eMMC driver bug and made > it more likely to happen). > > Opening GUI programs and moving windows around is another good stress. > > On 2/26/2014 9:48 AM, quik...@gmail.com <javascript:> wrote: > > The stress tool generates cpu load only. But it is a good idea to > consider > > other load scenarios, too. The current test was done using ssh so there > was > > at least some network activity. Do you know of a good test tool which > > allows to generate disk and network load? > > > > > > Am Mittwoch, 26. Februar 2014 15:58:55 UTC+1 schrieb Charles > Steinkuehler: > >> > >> Those are pretty good numbers. Did you have heavy network and disk > >> (uSD/eMMC) load going as well? IIRC, the uSD/eMMC driver was > >> responsible for the worst of the latency spikes I saw, but that's been > >> some time ago and based on the OMAP kernel list traffic, it appears > >> there have been lots of improvements to that code. > >> > >> On 2/26/2014 7:53 AM, quik...@gmail.com <javascript:> wrote: > >>> > >>> > >>> 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? > >>>> > >>>> > >>>> > >>> > >> > >> > >> -- > >> Charles Steinkuehler > >> cha...@steinkuehler.net <javascript:> > >> > > > > > -- > Charles Steinkuehler > cha...@steinkuehler.net <javascript:> > -- 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.
