According to the description of sched_setscheduler the priority is used to determine which process to run next. Normal processes with scheduling policy SCHED_OTHER have priority 0. SCHED_FIFO processes have higher priority, and under Linux it is likely that pd will be the only process in this group, and therefore it will have precedence. In this case it is of no use to give it higher priority than 1, because 1 will be the highest.
If JACK is running, pd's priority will be lower than JACK's. Which is how it should be.
So, the change should not affect normal realtime behaviour.
Guenter
well, now it's pd and jack ... in the future, there's no telling how crowded the space of "real-time" hungry processes will get. So maybe it's worth finding a general way to determine which level Pd should live at. Perhaps it should be just below the one jack chooses (and does anyone know that one?)
Miller