
Run both ./pitest-1 and ./pitest-2 as root
This requires the glibc robust futex updates from BULL/Montavista

pitest-1 has the following scenario, It starts 3 threads,
Thread A with SCHED_OTHER and prio 0,
Thread B with SCHED_RR and prio 40 and,
Thread C with SCHED_RR also with prio 40. (Noise Thread)

Thread A and B contend for the same mutex lock, with thread A grabbing
the lock first and gets prio boosted to that of thread B. In this case
I see that thread A gets all the cputime and once it releases the mutex,
thread B gets to run and once thread B is done only then thread C gets
to run. (thread C does not contend for the mutex, it just consumes CPU
cycles and is a noise thread)

Compare this with ./pitest-2 which is the same as ./pitest-1 except
Thread A with SCHED_RR and prio 10,
Thread B with SCHED_FIFO and prio 40 and,
Thread C with SCHED_RR also with prio 40. (Noise Thread)

Here Thread A again grabs the mutex first that is also contended by
thread B and thread A gets its prio boosted to that of thread B.
However I find that thread A and thread C now round robin until
thread A releases the lock, at which point only thread B gets to run
and once thread B is done, then thread C resumes

Also all tasks are affined to a single CPU to clearly indicate the
effects of PI boosting.


