[Xenomai] Slow execution of RT task

Jeroen Van den Keybus jeroen.vandenkeybus at gmail.com
Mon Apr 14 23:14:30 CEST 2014

> Maybe the clocksource is no longer the tsc? What does:
> cat /sys/devices/system/clocksource/clocksource0/current_clocksource
> say?


But I just discovered the reason of the increased execution times:
while looking for delays caused by the CPU accidentally entering C3
state, I turned on the I-pipe tracer and simply forgot to turn it back
off. I just learnt that the tracer causes an appreciable bit of

Kernel build time is now 2m27s and the times of the test program are now:

1397509817942908822:    -2317      134 T=   -2183 (0)
1397509818942908822:    -2307      129 T=   -2178 (0)
1397509819942908822:    -2306      129 T=   -2177 (0)

Sorry to have bothered you with this and thanks for your help.

Still, I do get these warnings in kernel/rcutree.c and, with the
tracer still on, the system at least locked up hard once while
modprobing xeno_native.

Thanks again,


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