NAME

       ptsematest - Start two threads and measure the latency of interprocess communication with POSIX mutex.

SYNTAX

       ptsematest [-a|-a PROC] [-b USEC] [-d DIST] [-i INTV] [-l loops] [-p PRIO] [-t|-t NUM]

DESCRIPTION

       The      program      ptsematest     starts     two     threads     that     are     synchronized     via
       pthread_mutex_unlock()/pthread_mutex_lock() and measures the latency between releasing  and  getting  the
       lock.

OPTIONS

       -a, --affinity[=PROC]
              Run on processor number PROC. If PROC is not specified, run on current processor.

       -b, --breaktrace=USEC
              Send  break  trace  command when latency > USEC. This is a debugging option to control the latency
              tracer in the realtime preemption patch.  It is useful to track down unexpected large latencies of
              a system.

       -d, --distance=DIST
              Set  the  distance  of  thread  intervals in microseconds (default is 500 us). When  cyclictest is
              called with the -t option and more than one thread is created, then this distance value  is  added
              to the interval of the threads: Interval(thread N) = Interval(thread N-1) + DIST

       -i, --interval=INTV
              Set  the  base  interval  of  the  thread(s)  in  microseconds (default is 1000 us). This sets the
              interval of the first thread. See also -d.

       -l, --loops=LOOPS
              Set the number of loops. The default is 0 (endless). This option is  useful  for  automated  tests
              with  a  given number of test cycles. ptsematest is stopped once the number of timer intervals has
              been reached.

       -p, --prio=PRIO
              Set the priority of the process.

       -t, --threads[=NUM]
              Set the number of test threads (default is 1, if this option is not given). If NUM  is  specified,
              create NUM test threads. If NUM is not specified, NUM is set to the number of available CPUs.

EXAMPLES

       The following example was running on a 4-way processor:

       # ptsematest -a -t -p99 -i100 -d25 -l1000000
       #0: ID8672, P99, CPU0, I100; #1: ID8673, P99, CPU0, Cycles 1000000
       #2: ID8674, P98, CPU1, I125; #3: ID8675, P98, CPU1, Cycles 811035
       #4: ID8676, P97, CPU2, I150; #5: ID8677, P97, CPU2, Cycles 668130
       #6: ID8678, P96, CPU3, I175; #7: ID8679, P96, CPU3, Cycles 589423
       #1 -> #0, Min    1, Cur    1, Avg    2, Max   11
       #3 -> #2, Min    1, Cur    2, Avg    2, Max   13
       #5 -> #4, Min    1, Cur    4, Avg    3, Max   12
       #7 -> #6, Min    1, Cur    4, Avg    2, Max   12

AUTHORS

       Carsten Emde <C.Emde@osadl.org>

SEE ALSO

       pthread_mutex_lock(3p), pthread_mutex_unlock(3p)

                                                       0.1                                         ptsematest(8)