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


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


       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.


       -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.


       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


       Carsten Emde <>


       mq_send(3p), mq_receive(3p)

                                      0.1                           pmqtest(8)