Jonathan ILIAS-PILLET wrote: > 2011/3/7 Gilles Chanteperdrix <[email protected]>: >> We do not know anything about your setup (except the platform). See: >> http://www.xenomai.org/index.php/Request_for_information > > Oh, sorry. Here it is : > - linux kernel : 2.6.29.6 > - adeos patch : adeos-ipipe-2.6.29-arm-1.13-00.patch > - xenomai : 2.4.8 > - host linux distribution : ubuntu 10.04 (64 bits) > - compiler : gcc 4.2.1 (buildroot's generated toolchain) > > For those who knows it, all of this comes from Armadeus distribution > (vendor package for the board we use) in version 3.3 which is based on > buildroot (see http://www.armadeus.com/wiki/).
This is very old stuff. Could you try whether you reproduce this issue with Xenomai latest release (2.5.5.2) ? Also, using 2.4.8 is preposterous, you should at least upgrade to the latest release from the same branch, it should be 2.4.9.1. > >> It would also be interesting to know if you have root thread priority >> coupling enabled. > > Actually, I've never choose any option about this, I thought it was > activated by default. Perhaps I messed the kernel configuration > related to this, where this feature can be enabled or disabled ? > > According to http://www.xenomai.org/index.php/Proc/xenomai/sched, I > guess it is enabled : > # cat /proc/xenomai/sched > CPU PID PRI PERIOD TIMEOUT TIMEBASE STAT NAME > 0 0 -1 0 0 master R ROOT No, you do not see anything here. You have to check the kernel configuration. Relying on someone else's configuration will not fly for long, you have to know what is in the kernel you compile. > > >> In any case, your real-time tasks should never use all the cpu without >> letting Linux run. The only way to guarantee the stability of the system >> is by letting Linux run from time to time. > > OK, I understand. Linux kernel is time dependant (at least for the > scheduler). But is there a specific reason for this or is it a general > precaution ? > > When you say "time to time", is there any rule to follow to be sure > that enough time is given to Linux ? Something like CPU cannot spend > more than 500 ms in one second for primary mode threads ? No. Something like your application should release the cpu once every 10ms so that Linux receives its ticks when it expects them (so, every 1ms if running at 1000 Hz). In fact, a typical application is blocked most of the time and only reacts to events (be it the timer interrupt). -- Gilles. _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
