Provided by: rt-tests_2.2-1_amd64 bug

NAME

       svsematest  -  Start  two  threads  or  fork two processes and measure the latency of SYSV
       semaphores

SYNTAX

       svsematest [-a|--affinity NUM] [-b|--breaktrace USEC] [-d|--distance DIST]  [-D|--duration
       TIME]   [-f|--fork  [OPT]]  [-i|--interval  INTV]  [--json  FILENAME]  [-l|--loops  LOOPS]
       [-p|--prio PRIO] [-q|--quiet] [-S|--smp] [-t|--threads [NUM]]

DESCRIPTION

       The program svsematest starts two threads or, optionally, forks  two  processes  that  are
       synchronized via SYSV semaphores and measures the latency between releasing a semaphore on
       one side and getting it on the other side.

OPTIONS

       -a, --affinity[=NUM]
              Run on processor number NUM. 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
              cyclictest  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.

       -f, --fork
              Instead of creating threads (which is the default), fork new processes

       -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. svsematest 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
              SMP testing: options -a -t and same priority of 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.

EXAMPLES

       The following example was running on a 4-way CPU:

       # svsematest -a -t -p99 -i100 -d25 -l1000000
       #0: ID13110, P99, CPU0, I100; #1: ID13111, P99, CPU0, Cycles 1000000
       #2: ID13112, P98, CPU1, I125; #3: ID13113, P98, CPU1, Cycles 813573
       #4: ID13114, P97, CPU2, I150; #5: ID13115, P97, CPU2, Cycles 667285
       #6: ID13116, P96, CPU3, I175; #7: ID13117, P96, CPU3, Cycles 591403
       #1 -> #0, Min    1, Cur    2, Avg    2, Max   12
       #3 -> #2, Min    1, Cur    3, Avg    2, Max   12
       #5 -> #4, Min    1, Cur    3, Avg    3, Max   12
       #7 -> #6, Min    1, Cur    2, Avg    3, Max   11

AUTHORS

       Carsten Emde <C.Emde@osadl.org>

SEE ALSO

       semop(2)

                                               0.1                                  svsematest(8)