NAME

       pmqtest  -  Start  pairs  of  threads  and  measure  the latency of interprocess communication with POSIX
       messages queues

SYNTAX

       pmqtest [-a|-a PROC] [-b USEC] [-d DIST] [-i INTV] [-l loops] [-p PRIO] [-S] [-t|-t NUM] [-T TO]

DESCRIPTION

       The program pmqtest starts pairs of threads that are synchronized via mq_send/mw_receive()  and  measures
       the latency between sending and receiving the message.

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 pmqtest  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

       -f, --forcetimeout=TO
              Set an artificial delay of the send function to force timeout of the  receiver,  requires  the  -T
              option

       -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. pmqtest is stopped once the number of timer intervals has been
              reached.

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

       -S, --smp
              Test  mode  for  symmetric  multi-processing,  implies -a and -t and uses the same priority on all
              threads.

       -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.

       -T, --timeout=TO
              Use mq_timedreceive() instead of mq_receive() and specify timeout TO in seconds.

EXAMPLES

       The following example was running on an 8-way processor:

       # pmqtest -Sp99 -i100 -d0
       #0: ID10047, P99, CPU0, I100; #1: ID10048, P99, CPU0, Cycles 153695
       #2: ID10049, P99, CPU1, I100; #3: ID10050, P99, CPU1, Cycles 154211
       #4: ID10051, P99, CPU2, I100; #5: ID10052, P99, CPU2, Cycles 156823
       #6: ID10053, P99, CPU3, I100; #7: ID10054, P99, CPU3, Cycles 158202
       #8: ID10055, P99, CPU4, I100; #9: ID10056, P99, CPU4, Cycles 153399
       #10: ID10057, P99, CPU5, I100; #11: ID10058, P99, CPU5, Cycles 153992
       #12: ID10059, P99, CPU6, I100; #13: ID10060, P99, CPU6, Cycles 156576
       #14: ID10061, P99, CPU7, I100; #15: ID10062, P99, CPU7, Cycles 157957
       #1 -> #0, Min    1, Cur    8, Avg    5, Max   18
       #3 -> #2, Min    1, Cur    4, Avg    5, Max   18
       #5 -> #4, Min    1, Cur    5, Avg    5, Max   19
       #7 -> #6, Min    1, Cur    4, Avg    4, Max   17
       #9 -> #8, Min    1, Cur    9, Avg    5, Max   18
       #11 -> #10, Min    1, Cur    8, Avg    5, Max   18
       #13 -> #12, Min    1, Cur    4, Avg    5, Max   29
       #15 -> #14, Min    1, Cur    8, Avg    4, Max   17

AUTHORS

       Carsten Emde <C.Emde@osadl.org>

SEE ALSO

       mq_send(3p), mq_receive(3p)

                                                       0.1                                            pmqtest(8)