Gregory CLEMENT wrote: > Here, they are the last latency we get on AT91SAM9261-EK. As just now > I haven't the board at home, I send the last result we stored. The > prority of dbgu should be set to 6 instead of 7, but I can't assure > it, for Xenomai.
Hmm, hardware interrupt priorities must not impact the worst-case latency if I-pipe acks and mask them appropriately (the worst case is when multiple interrupts happen in a row, not at the same time). But this statement is not based on knowledge about potential pitfalls of this arch. Are there specialities that require this tweaking? > first Xenomai: > > #insmod > /lib/modules/2.6.20.13/kernel/drivers/xenomai/testing/xeno_timerbench.ko > #cd /usr/xenomai/bin/ Which versions were you using for both tests? Do you still have the involved .configs? > #./latency -t 2 -p 150 -h -H 500 ... > ---|------------|------------|------------|--------|------------------------- > RTS| 3.480| 11.779| 99.163| 0| 14:23:01/14:23:01 > > It was run under calibrator load during more than 14 hours. > > Now RTAI: > > Oneshot timer with 500µs period, LATENCY =6000ns and SETUPTIME 1500 > duration : 17h > > 1970/01/1 22:34:51 > RTH| lat min| ovl min| lat avg| lat max| ovl max| overruns > RTD| 3221| 2577| 4997| 26095| 53801| 0 > RTD| 3221| 2577| 5163| 25451| 53801| 0 > RTD| 3221| 2577| 5159| 25128| 53801| 0 > RTD| 3221| 2577| 4799| 23518| 53801| 0 > RTD| 3221| 2577| 4828| 25128| 53801| 0 > RTD| 3221| 2577| 5089| 23518| 53801| 0 > RTD| 3221| 2577| 4580| 23840| 53801| 0 > RTD| 3221| 2577| 4924| 25128| 53801| 0 > RTD| 3221| 2577| 4740| 24806| 53801| 0 > RTD| 3221| 2577| 4251| 25128| 53801| 0 Again, what would simplify the discussion enormously is a function back-trace of the measured maximum latencies, just like "latency -f" generates. The numbers will become worse, for sure, but we would gain a very good overview about what is executed and what delayed which kernel. If you see a chance to perform such a test and you need some hints on the tracer setup (or did you use it before?), please let us know! Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux _______________________________________________ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
