Hi Gilles, I understand. I have a beaglebone too and as soon as possible I will make some test on it.
Thank you for all help and attention, Bruno Em Terça-feira, 4 de Março de 2014 12:13, Gilles Chanteperdrix <[email protected]> escreveu: On 03/04/2014 04:47 AM, Bruno Tunes de Mello wrote: > Hi Gilles, > > You are right, in the first test, I executed both latency and xeno-test > commands. Sorry. > The others test I executed only latency command. > > I tried to enable the discard service on /etc/inetd.conf, I don't know if I > did it right, but in /etc/services file I found 'discard 9/tcp sink null' and > 'discard 9/udp sink null'. > Then I used the command you said: > xeno-test -l "dohell -s 192.168.0.5 -m /media/linaro/PENDRIVE -l /opt/ltp" -c > 0 -p 100 -g histo > > I tested a few times and the better result is: > http://pt-br.tinypic.com/r/206mmvn/8 > This result is not so good like that you showed. > > My doubt is if this result is satisfactory (the platform is ready for develop > applications) or do you think that I need to do some correction? 70us is a bit high, but on the other hand: - the mx6q is a quad-core, whereas the omap4 is a dual core, the latency increases with the number of cores; - the tests I make on omap4 do not use much of the processor peripherals, such as the graphic co-processor, so, if you use the graphic co-processor, you may observe an increase in latencies as well. Finally, whether this is satisfactory depends on your application. The only way to improve latency is to enable the I-pipe tracer, and try and understand where the maximum latency come from, but this is time consuming. Also, some settings are known to result in an improvement in latencies: - turn off CONFIG_PREEMPT (i.e. enable CONFIG_PREEMPT_NONE), this looks contradictory, as the menu entry says "low latency", but it is talking about Linux latencies, not Xenomai's - build kernel and user-space in thumb2 - disable Xenomai unlocked context switch But do not expect these settings to reduce the latency by more than say 5us. -- Gilles. _______________________________________________ Xenomai mailing list [email protected] http://www.xenomai.org/mailman/listinfo/xenomai
