[linux-audio-dev] [CODE RFC] redefining sched_setscheduler using LD_PRELOAD

Hi, (Jack O'Quin got me thinking about rt_monitor again - thanks!) This is an alternative to capabilities / SCHED_SOFTRR... I use my old rt_monitor * protects the system on RT overload * performs the actual setting of scheduler type * it does not even have to be visible for lusers! My old testprogram RT has been converted to a library fit for preloading. It works like this. As root start # rt_monitor As normal user start latencytest $ ./rts path/to/latencytest none 2 128 10 rts has two options -i do not raise the priority. -v be more verbose. * It does also limit the effective min/max range. Do also try (don't try this as root unless rt_monitor is running) $ ./rts path/to/latencytest none 2 1024 99 * In this case rt_monitor captures the process and renices it. (SCHED_OTHER + nice) BUGS: * better build and installation system * could ignore RT processes already running when rt_monitor starts * rt_monitor functionallity has not been reverified... * it can't lock memory :-( No PIDs in calls. * code that checks uid before using the redefined functions won't work (I have an modified latencytest) * client get stuck if there is no monitor running. /RogerL -- Roger Larsson Skellefteå Sweden