> > > Aha! I think you are on to something! I double checked the priority of > > > the jack clients and _they_ are not getting SCHED_FIFO!! They should be > > > getting that priority from the jack server but they are not (and the > > > jack server is not complaining at all so no error is being raised). > > > Probably some change in glibc, I would think... > > I had begun to notice some of this, too. But, I hadn't figured out > what was going on. I have been banging my head on walls for a while trying to find out what was causing the xruns... > > Just confirmed this with a first preliminary hack (and test). Jack > > creates new threads and to do that it sets up a pthread_attr_t struct > > and uses pthread_attr_setschedpolicy and pthread_attr_setscope to set > > the scheduling policy (and also sets the priority) in the struct. Then > > pthread_create is called (with that struct as an argument) and the > > thread is created. But the thread created is _not_ SCHED_FIFO and there > > is no error return. If _after_ the thread is created I double check the > > scheduling policy and use pthread_setschedparam to again set it to > > SCHED_FIFO then the thread changes to SCHED_FIFO... go figure... > > Is this only with NPTL or on any 2.6.6 system? I have only tested on FC2 and 2.6.6. I presume this means NPTL. -- Fernando
