Hi, > Henry Bausley wrote: > > Is there any way the kernel mode interrupt handling maximum times can be > > decreased. I very much need to reduce my kernel mode interrupt > > latencies. I know my hardware is capable of better performance based > > upon measurements done with RT Linux. Below is our timing comparison, > > all times are the maximums. > > > > > > Xenomai 2.4.5 interrupt handler w/ Kernel 2.6.26 powerpc, gcc 4.2 > > ------------------------------------------------------------------- > > AMCC 440EP - 24.5 usec > > AMCC 460EX - 16.5 usec > > > > > > FSM Labs RT-Linux 2.2 w/ Kernel 2.6.14 ppc, gcc 3.3 > > --------------------------------------------------- > > AMCC 440EP - 10.0 usec > > AMCC 460EX - Not Available, would require 10's of thousands of dollars > > to WindRiver > > It would be interesting to know the figures for 2.6.14 ppc w/o RTLinux + > Xenomai 2.4.5.
Just for information, I was able to launch some tests on an AMCC PPC440EP eval board (yosemite I think) I borrowed. I did not have the time to change the configuration so I launched the latency test (-t 0) on a Linux kernel 2.6.19 +Xenomai 2.3.3 (no module). The results are in the same range: ./latency -t 0 + ping -f + ls -lR / RTT| 00:10:31 (periodic user-mode task, 100 us period, priority 99) RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat worst RTD| -3.744| -2.379| 14.660| 0| -4.333| 26.621 RTD| -3.744| -2.236| 13.198| 0| -4.333| 26.621 RTD| -3.738| -2.259| 15.240| 0| -4.333| 26.621 RTD| -3.744| -2.349| 12.870| 0| -4.333| 26.621 RTD| -3.744| -2.304| 14.752| 0| -4.333| 26.621 There is no finetuning in /proc/xenomai/latency: # cat /proc/xenomai/latency 9498 Alexis. _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
