switchtest (1)

switchtest [options] threadspec threadspec...

switchtest is part of Xenomai. It can be used to test thread context switches. switchtest creates threads of various types and attempts to switch context between these threads, printing the count of context switches every second. A suitable Xenomai enabled kernel with the respective module (xeno_posix) must be installed.

Each threadspec specifies the characteristics of a thread to be created:

threadspec = (rtk|rtup|rtus|rtuo)(_fp|_ufpp|_ufps)*[0-9]*

rtk

for a kernel-space real-time thread

rtup

for a user-space real-time thread running in primary mode

rtus

for a user-space real-time thread running in secondary mode

rtuo

for a user-space real-time thread oscillating between primary and secondary mode

_fp

means that the created thread will have the XNFPU bit armed (only valid for rtk)

_ufpp

means that the created thread will use the FPU when in primary mode\n(invalid for rtus)

_ufps

means that the created thread will use the FPU when in secondary mode (invalid for rtk and rtup)

[0-9]

specifies the ID of the CPU where the created thread will run, 0 if unspecified

Passing no threadspec is equivalent to running:

switchtest rtkN rtkN rtk_fpN rtk_fpN rtk_fp_ufppN rtk_fp_ufppN rtupN rtupN rtup_ufppN rtup_ufppN rtusN rtusN rtus_ufpsN rtus_ufpsN rtuoN rtuoN rtuo_ufppN rtuo_ufppN rtuo_ufpsN rtuo_ufpsN rtuo_ufpp_ufpsN rtuo_ufpp_ufpsN

with N=1,...,nr_cpus, i.e. occurrences of all the arguments for each CPU

Passing only the --nofpu or -n argument is equivalent to running:

switchtest rtkN rtkN rtupN rtupN rtusN rtusN rtuoN rtuoN

similar to the above.

switchtest accepts the following options:

--help, -h

print usage information and exit

--lines <lines>, -l <lines>

print headers every <lines> lines

--quiet or -q

prevent this program from printing every second the count of ncontext switches

--timeout <duration>, -T <duration>

limit the test duration to <duration> seconds

--nofpu, -n

disables any use of FPU instructions

switchtest was written by Philippe Gerum and Gilles Chanteperdrix. This man page was written by Roland Stigge.