Re: [Xenomai-help] help with xenomai configuration

[Philippe Gerum <rpm@xenomai.org>]

On Tue, 2009-05-05 at 15:23 +0200, Gilles Chanteperdrix wrote:
> henning.richter@domain.hid wrote:
> > 
> > Hi,
> > 
> > I use a KUbuntu 8.10 with kernel 2.6.27.7, xenomai 2.4.6.1 and the latest
> > rtnet version.
> > I set up the EthercatMasterLibrary and send some Frames (size of ~1200
> > byte) cylical to my Beckhoff devices.
> > Measuring the time (via rt_read_timer-function of timer.h) handing the
> > frames over to the NIC last between 5 and 10 us. (its the low_level_send)
> > Measuring the time at the application layer is takes ~250 - 350 us. So I am
> > loosing quite a lot time in between.
> > 
> > Maybe there is sth. wrong with my xenomai configuration.
> > I run the 'xeno-test' (results below) but the test stop at generation load.
> 
> Yes, xeno-test has a known issue when run without bash, and ubuntu no
> longer uses bash by default. So, try running xeno-test with bash.
> 

Gilles, we have an ongoing series of recurring issues with xeno-test
that pleads for a reshuffle. I would really like to see something
simpler in there, which may not cover all aspects that xeno-test
currently addresses, but which would at least work for all setups, and
particularly embedded ones.

We should rather see xeno-test as a simple validation tool to dig out
most common latency issues due to bad kernel settings. Further
validation via long running stress tests would be better accomplished
via the LTP-based suite we use internally to validate ports, within
standalone mini-rootfs; maybe at some point we could provide those
pre-built rootfs for download, for that particular purpose.

> Alternatively, you can run the latency test directly. Preferably using
> the same period as the problematic one with EML.
> 
-- 
Philippe.