tools/perf/Documentation/perf-ftrace.txt

Source file repositories/reference/linux-study-clean/tools/perf/Documentation/perf-ftrace.txt

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Linux kernel
Corpus path
tools/perf/Documentation/perf-ftrace.txt
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.txt
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6996 bytes
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226
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

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Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

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perf-ftrace(1)
==============

NAME
----
perf-ftrace - simple wrapper for kernel's ftrace functionality


SYNOPSIS
--------
[verse]
'perf ftrace' {trace|latency|profile} <command>

DESCRIPTION
-----------
The 'perf ftrace' command provides a collection of subcommands which use
kernel's ftrace infrastructure.

  'perf ftrace trace' is a simple wrapper of the ftrace.  It only supports
  single thread tracing currently and just reads trace_pipe in text and then
  write it to stdout.

  'perf ftrace latency' calculates execution latency of a given function
  (optionally with BPF) and display it as a histogram.

  'perf ftrace profile' show a execution profile for each function including
  total, average, max time and the number of calls.

The following options apply to perf ftrace.

COMMON OPTIONS
--------------

-p::
--pid=::
	Trace on existing process id (comma separated list).

--tid=::
	Trace on existing thread id (comma separated list).

-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.

-v::
--verbose::
        Increase the verbosity level.


OPTIONS for 'perf ftrace trace'
-------------------------------

-t::
--tracer=::
	Tracer to use when neither -G nor -F option is not
	specified: function_graph or function.

-F::
--funcs::
        List available functions to trace. It accepts a pattern to

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