https://github.com/torvalds/linux
Tip revision: 856deb866d16e29bd65952e0289066f6078af773 authored by Linus Torvalds on 13 September 2020, 23:06:00 UTC
Linux 5.9-rc5
Linux 5.9-rc5
Tip revision: 856deb8
perf-ftrace.txt
perf-ftrace(1)
==============
NAME
----
perf-ftrace - simple wrapper for kernel's ftrace functionality
SYNOPSIS
--------
[verse]
'perf ftrace' <command>
DESCRIPTION
-----------
The 'perf ftrace' command is a simple wrapper of kernel's ftrace
functionality. It only supports single thread tracing currently and
just reads trace_pipe in text and then write it to stdout.
The following options apply to perf ftrace.
OPTIONS
-------
-t::
--tracer=::
Tracer to use when neither -G nor -F option is not
specified: function_graph or function.
-v::
--verbose=::
Verbosity level.
-F::
--funcs::
List all available functions to trace.
-p::
--pid=::
Trace on existing process id (comma separated list).
--tid=::
Trace on existing thread id (comma separated list).
-D::
--delay::
Time (ms) to wait before starting tracing after program start.
-a::
--all-cpus::
Force system-wide collection. Scripts run without a <command>
normally use -a by default, while scripts run with a <command>
normally don't - this option allows the latter to be run in
system-wide mode.
-C::
--cpu=::
Only trace for the list of CPUs provided. Multiple CPUs can
be provided as a comma separated list with no space like: 0,1.
Ranges of CPUs are specified with -: 0-2.
Default is to trace on all online CPUs.
-m::
--buffer-size::
Set the size of per-cpu tracing buffer, <size> is expected to
be a number with appended unit character - B/K/M/G.
--inherit::
Trace children processes spawned by our target.
-T::
--trace-funcs=::
Select function tracer and set function filter on the given
function (or a glob pattern). Multiple functions can be given
by using this option more than once. The function argument also
can be a glob pattern. It will be passed to 'set_ftrace_filter'
in tracefs.
-N::
--notrace-funcs=::
Select function tracer and do not trace functions given by the
argument. Like -T option, this can be used more than once to
specify multiple functions (or glob patterns). It will be
passed to 'set_ftrace_notrace' in tracefs.
--func-opts::
List of options allowed to set:
call-graph - Display kernel stack trace for function tracer.
irq-info - Display irq context info for function tracer.
-G::
--graph-funcs=::
Select function_graph tracer and set graph filter on the given
function (or a glob pattern). This is useful to trace for
functions executed from the given function. This can be used more
than once to specify multiple functions. It will be passed to
'set_graph_function' in tracefs.
-g::
--nograph-funcs=::
Select function_graph tracer and set graph notrace filter on the
given function (or a glob pattern). Like -G option, this is useful
for the function_graph tracer only and disables tracing for function
executed from the given function. This can be used more than once to
specify multiple functions. It will be passed to 'set_graph_notrace'
in tracefs.
--graph-opts::
List of options allowed to set:
nosleep-time - Measure on-CPU time only for function_graph tracer.
noirqs - Ignore functions that happen inside interrupt.
verbose - Show process names, PIDs, timestamps, etc.
thresh=<n> - Setup trace duration threshold in microseconds.
depth=<n> - Set max depth for function graph tracer to follow.
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-trace[1]