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. Aside of this, I'm working on an experimental patch which implements unmasked context switches on the Linux side. I stole this idea from Gilles, who drastically decreased latency on ARM this way. This will not decrease the user-space latency on powerpc, but this might help in-kernel interrupt latency, by allowing interrupts to be taken while changing the MMU context. I'll post that stuff this week if it happens to decrease the in-kernel latency significantly. > > > > _______________________________________________ > Xenomai-help mailing list > [email protected] > https://mail.gna.org/listinfo/xenomai-help > -- Philippe. _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
