Ubuntu Manpage: pmqtest - Start pairs of threads and measure the latency of interprocess communication

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]  [-D  TIME]  [-f  TO]  [-h]  [-i  INTV]  [--json
       FILENAME] [-l LOOPS] [-p PRIO] [-q] [-S] [-t|-t NUM]

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 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
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

-D, --duration=TIME
Specify a length for the test run.
Append 'm', 'h', or 'd' to specify minutes, hours or days.

-h, --help
Print help message

-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.

--json=FILENAME
Write final results into FILENAME, JSON formatted.

-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.

-q, --quiet
Print a summary only on exit. Useful for automated tests, where only the summary
output needs to be captured.

-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 specified, 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

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