1pmqtest(8)                                                          pmqtest(8)
2
3
4

NAME

6       pmqtest  -  Start pairs of threads and measure the latency of interpro‐
7       cess communication with POSIX messages queues
8

SYNTAX

10       pmqtest [-a|-a PROC] [-b USEC] [-d DIST] [-D TIME]  [-f  TO]  [-h]  [-i
11       INTV] [--json FILENAME] [-l LOOPS] [-p PRIO] [-q] [-S] [-t|-t NUM]
12

DESCRIPTION

14       The  program  pmqtest starts pairs of threads that are synchronized via
15       mq_send/mw_receive() and measures the latency between sending  and  re‐
16       ceiving the message.
17

OPTIONS

19       -a, --affinity[=PROC]
20              Run  on  processor number PROC. If PROC is not specified, run on
21              current processor.
22
23       -b, --breaktrace=USEC
24              Send break trace command when latency > USEC. This is  a  debug‐
25              ging  option  to control the latency tracer in the realtime pre‐
26              emption patch.  It is useful to track down unexpected large  la‐
27              tencies of a system.
28
29       -d, --distance=DIST
30              Set the distance of thread intervals in microseconds (default is
31              500 us). When pmqtest is called with the -t option and more than
32              one  thread is created, then this distance value is added to the
33              interval of the threads: Interval(thread  N)  =  Interval(thread
34              N-1) + DIST
35
36       -D, --duration=TIME
37              Specify a length for the test run.
38              Append 'm', 'h', or 'd' to specify minutes, hours or days.
39
40       -h, --help
41              Print help message
42
43       -f, --forcetimeout=TO
44              Set an artificial delay of the send function to force timeout of
45              the receiver, requires the -T option
46
47       -i, --interval=INTV
48              Set the base interval of the thread(s) in microseconds  (default
49              is  1000  us).  This  sets the interval of the first thread. See
50              also -d.
51
52       --json=FILENAME
53              Write final results into FILENAME, JSON formatted.
54
55       -l, --loops=LOOPS
56              Set the number of loops. The default is 0 (endless). This option
57              is  useful  for  automated tests with a given number of test cy‐
58              cles. pmqtest is stopped once the number of timer intervals  has
59              been reached.
60
61       -p, --prio=PRIO
62              Set the priority of the process.
63
64       -q, --quiet
65              Print  a summary only on exit. Useful for automated tests, where
66              only the summary output needs to be captured.
67
68       -S, --smp
69              Test mode for symmetric multi-processing, implies -a and -t  and
70              uses the same priority on all threads.
71
72       -t, --threads[=NUM]
73              Set  the number of test threads (default is 1, if this option is
74              not given). If NUM is specified, create NUM test threads. If NUM
75              is not specified, NUM is set to the number of available CPUs.
76
77       -T, --timeout=TO
78              Use  mq_timedreceive() instead of mq_receive() and specify time‐
79              out TO in seconds.
80

EXAMPLES

82       The following example was running on an 8-way processor:
83
84       # pmqtest -Sp99 -i100 -d0
85       #0: ID10047, P99, CPU0, I100; #1: ID10048, P99, CPU0, Cycles 153695
86       #2: ID10049, P99, CPU1, I100; #3: ID10050, P99, CPU1, Cycles 154211
87       #4: ID10051, P99, CPU2, I100; #5: ID10052, P99, CPU2, Cycles 156823
88       #6: ID10053, P99, CPU3, I100; #7: ID10054, P99, CPU3, Cycles 158202
89       #8: ID10055, P99, CPU4, I100; #9: ID10056, P99, CPU4, Cycles 153399
90       #10: ID10057, P99, CPU5, I100; #11: ID10058, P99, CPU5, Cycles 153992
91       #12: ID10059, P99, CPU6, I100; #13: ID10060, P99, CPU6, Cycles 156576
92       #14: ID10061, P99, CPU7, I100; #15: ID10062, P99, CPU7, Cycles 157957
93       #1 -> #0, Min    1, Cur    8, Avg    5, Max   18
94       #3 -> #2, Min    1, Cur    4, Avg    5, Max   18
95       #5 -> #4, Min    1, Cur    5, Avg    5, Max   19
96       #7 -> #6, Min    1, Cur    4, Avg    4, Max   17
97       #9 -> #8, Min    1, Cur    9, Avg    5, Max   18
98       #11 -> #10, Min    1, Cur    8, Avg    5, Max   18
99       #13 -> #12, Min    1, Cur    4, Avg    5, Max   29
100       #15 -> #14, Min    1, Cur    8, Avg    4, Max   17
101

AUTHORS

103       Carsten Emde <C.Emde@osadl.org>
104

SEE ALSO

106       mq_send(3p), mq_receive(3p)
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108
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110                                      0.1                           pmqtest(8)
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