Provided by: rt-tests_2.5-1_amd64 bug

NAME

       cyclictest - High resolution test program

SYNOPSIS

       cyclictest [ -hfmnqrsvMS ] [-a proc ] [-A align ] [-b usec ] [-c clock ] [-d dist ] [-h
                  histogram ] [-i intv ] [--json filename ] [-l loop ] [-o red ] [-p prio ] [-t
                  num ] [-D time] [-w] [-W] [-y policy ] [ -S | -U ]

OPTIONS

       These programs follow the usual GNU command line syntax, with long options starting with
       two dashes ('--').
       A summary of options is included below.

       -a, --affinity[=PROC-SET]
              Run threads on the set of processors given by PROC-SET.  If PROC-SET is not
              specified, all processors will be used.  Threads will be assigned to processors in
              the set in numeric order, in a round-robin fashion.
              The set of processors can be specified as A,B,C, or A-C, or A-B,D-F, and so on*.
              The ! character can be used to negate a set.  For example, !B-D means to use all
              available CPUs except B through D.  The cpu numbers are the same as shown in the
              processor field in /proc/cpuinfo.  See numa(3) for more information on specifying
              CPU sets.  * Support for CPU sets requires libnuma version >= 2.  For libnuma v1,
              PROC-SET, if specified, must be a single CPU number.

       -A, --align=USEC
              Align thread wakeups to a specific offset in microseconds

       -b, --breaktrace=USEC
              Send break trace command when latency > USEC

       -c, --clock=CLOCK
              select clock
              0 = CLOCK_MONOTONIC (default)
              1 = CLOCK_REALTIME

       --default-system
              Don't attempt to tune the system from cyclictest. Power management is not
              suppressed. This might give poorer results, but will allow you to discover if you
              need to tune the system.

       -d, --distance=DIST
              Distance of thread intervals in us, default = 500

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

       -F, --fifo=<path>
              Create a named pipe at path and write stats to it

       -h, --histogram=US
              Dump latency histogram to stdout after the run. US is the max latency time to be be
              tracked in microseconds. This option runs all threads at the same priority.

       -H, --histofall=MAXLATENCYINUS
              Same as -h except that an additional histogram column is displayed at the right
              that contains summary data of all thread histograms. If cyclictest runs a single
              thread only, the -H option is equivalent to -h.

       --histfile=<path>
              Dump the latency histogram to <path> instead of stdout.

       -i, --interval=INTV
              Set the base interval of the thread(s) in microseconds (default is 1000us). This
              sets the interval of the first thread. See also -d.

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

       --laptop
              Save battery when running cyclictest. This will give you poorer realtime results,
              but will not drain your battery so quickly.

       --latency=PM_Q0S
              power management latency target value. This value is written to
              /dev/cpu_dma_latency and affects c-states. The default is 0

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

       --mainaffinity=CPUSET
              Run the main thread on CPU #N. This only affects the main thread and not the
              measurement threads

       -m, --mlockall
              Lock current and future memory allocations to prevent being paged out

       -M, --refresh_on_max
              Delay updating the screen until a new max latency is hit. (useful for running
              cyclictest on low-bandwidth connections)

       -N, --nsecs
              Show results in nanoseconds instead of microseconds, which is the default unit.

       -o, --oscope=RED
              Oscilloscope mode, reduce verbose output by RED.

       -p, --prio=PRIO
              Set the priority of the first thread. The given priority is set to the first test
              thread. Each further thread gets a lower priority: Priority(Thread N) =
              max(Priority(Thread N-1) - 1, 0)

       --policy=NAME
              set the scheduler policy of the measurement threads where NAME is one of: other,
              normal, batch, idle, fifo, rr

       --priospread
              spread priority levels starting at a specified value

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

       -r, --relative
              Use relative timers instead of absolute. The default behaviour of the tests is to
              use absolute timers. This option is there for completeness and should not be used
              for reproducible tests.

       -R, --resolution
              Check clock resolution, calling clock_gettime() many times. List of lock_gettime()
              values will be reported with -X

       --secaligned [USEC]
              align thread wakeups to the next full second and apply the optional offset.

       -s, --system
              Use sys_nanosleep and sys_setitimer instead of posix timers. Note, that -s can only
              be used with one thread because itimers are per process and not per thread. -s uses
              the nanosleep syscall and is not restricted to one thread.

       -S, --smp
              Set options for standard testing on SMP systems. Equivalent to using the options:
              "-t -a" as well keeping any specified priority equal across all threads

       --spike=<trigger>
              record all spikes > trigger

       --spike-nodes=[num of nodes]
              These are the maximum number of spikes we can record.
              The default is 1024 if not specified.

       --smi  Enable SMI count/detection on processors with SMI count support.

       -t, --threads[=NUM]
              Set the number of test threads (default is 1). Create NUM test threads. If NUM is
              not specified, NUM is set to the number of available CPUs. See -d, -i and -p for
              further information.

       --tracemark
              write a trace mark when -b latency is exceeded.

       -u, --unbuffered
              force unbuffered output for live processing

       -v, --verbose
              Output values on stdout for statistics. This option is used to gather statistical
              information about the latency distribution. The output is sent to stdout. The
              output format is:

              n:c:v

              where n=task number c=count v=latency value in us.

       --dbg_cyclictest
              Print info userful for debugging cyclictest

       -x, --posix_timers
              Use POSIX timers instead of clock_nanosleep.

SEE ALSO

       numa(3), numactl(8),

AUTHOR

       cyclictest was written by Thomas Gleixner <tglx@linuxtronix.de>.

       This manual page was written by Alessio Igor Bogani <abogani@texware.it>, for the Debian
       project (but may be used by others).
       Updated by John Kacur <jkacur@redhat.com>

                                          April 22, 2016                            CYCLICTEST(8)