Philippe Gerum wrote: > Jan Kiszka wrote: > > Hi, > > > > this is an experimental hack to open the non-rt priority levels of Linux > > to Xenomai shadow threads, i.e. allow shadows to be scheduled under > > SCHED_NORMAL when in secondary mode. The scenario are typical borderline > > threads between RT and non-RT: they share a critical code path with RT > > threads, maybe mutex protected, but they are mostly time-sharing threads > > which do not need SCHED_FIFO for this. > > > > The patch (be careful, quick-hack!) addresses the prio level 0 in the > > ipipe patch, the nucleus/shadow subsystem, and the native skin. A quick > > test with the attached demo showed the expected behaviour so far: no > > lock-up during busy-waiting in secondary mode, prio-boost when holding > > the lock (visible via /proc/xenomai/sched), no obvious side effects. > > > > Any comments? Does this break other things in a subtle way? > > An initial comment on the general usage of this extension: since the > threads running in SCHED_OTHER/SCHED_NORMAL mode are expected to run > non-RT workloads while still being able to use the RT infrastructure for > communicating with the rest of the RT system, I think that the best > places for creating such hybrids are in the rt_task_shadow (native skin) > and pthread_setschedparam (POSIX skin) calls, which would make it clear > that a regular Linux thread is involved [and as such needs to be created > by a normal call to pthread_create()], which also happens to benefit > from the RT infrastructure mainly for communication/sychronization purpose.
What about keeping SCHED_RR as the default scheduling policy and requiring users to manually select SCHED_NORMAL in thread creation attributes in order to create hybrid threads with pthread_create ? -- Gilles Chanteperdrix. _______________________________________________ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core