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 procesor 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
              cylictest  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 specifed, 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)