> This looks strange. Each call to select should result in a call to > Xenomai "select" syscall, if you are using the POSIX skin, which should > return -ENOSYS, then select should call the glibc select. Since > obviously what you want is to call glibc select directly, you can try > calling __real_select instead.
Indeed we replaced the "select"-call by a "poll"-call and the problem astonishingly disappeared (or it just shifted). Perhaps this is a hint what´s going wrong? Perhaps a __real_select would work too. I will try this, as soon as we can reproduce the effect in office (at the moment problem occurs only at customer). Just to understand things right: Xenomai-select returns ENOSYS as the option CONFIG_XENO_OPT_RTDM_SELECT isn´t set? (CONFIG_XENO_OPT_POSIX_SELECT isn´t available in 2.4.9, at least in my config-file). What would happen when CONFIG_XENO_OPT_RTDM_SELECT was set? > > Note that the issue with priorities you observe show that you have a > task with a priority higher than 0 using a glibc syscall, thereby > causing it to switch to secondary mode. The fact that lower priority > threads do not run is the effect of the "priority coupling", but the > real issue here is that a task with real-time priority is using a linux > syscall, which is something you should normally avoid. > But isn´t this the idea with "priority coupling", that the kernel is executed with realtime task priority? What should "priority coupling" be good for, when I have to avoid linux sys-calls? And, as Philippe wrote, the realtime task blocks as soon as the linux sys-call blocks and so the other realtime tasks get CPU again. Did I misunderstood something? Roderik -------------------------------------------------------- manroland AG Vorsitzender des Aufsichtsrates: Hanno C. Fiedler Vorstand: Gerd Finkbeiner (Vorsitzender), Dr. Ingo Koch, Dr. Markus Rall, Paul Steidle Sitz der Gesellschaft: Offenbach am Main, Registergericht: Amtsgericht Offenbach HRB-Nr. 42592 USt-Ident-Nr. DE 250200933 _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
