Wolfgang Grandegger wrote: >On 10/11/2005 05:11 PM Fillod Stephane wrote: >> Heikki Lindholm wrote: >> [..] >>> Probably, but there are less than awesome 4xx boards around and I'd >>> guess they might even be more likely targets than G4 based machines, >> for >>> example. Some tuning might be needed. >> >> How many people are using Xenomai (or Fusion) on 4xx ? >> What are their typical sched latency ? > >Attached is the result of some latency measurements on the Ocotea eval >board. The AMCC 440 GX is already a fast 4xx processor. Unfortunately, >the linuxppc-2.6.10rc3 does not run on our Ebony board. Nevertheless, >it's difficult to provide a resonable default value. Why not simply >using 0 and it's then up to the user to provide an appropriate value >at configuration time?
If it helps, know there's 2.6.10 and 2.6.11 (CONFIG_PREEMPT disabled though) ADEOS patches available for ppc. My latency measurements for Freescale e500 are here: https://mail.gna.org/public/rtai-dev/2005-02/msg00045.html It looks like an ADEOS/I-Pipe patch for current Linux kernels is much expected. The default calibration value may be set according to L1_CACHE_BYTES. Of course I'm fine with a default value set to 0, which is closer to my end of the spectrum :-) -- Stephane
