1perf-ftrace(1)
2==============
3
4NAME
5----
6perf-ftrace - simple wrapper for kernel's ftrace functionality
7
8
9SYNOPSIS
10--------
11[verse]
12'perf ftrace' {trace|latency|profile} <command>
13
14DESCRIPTION
15-----------
16The 'perf ftrace' command provides a collection of subcommands which use
17kernel's ftrace infrastructure.
18
19  'perf ftrace trace' is a simple wrapper of the ftrace.  It only supports
20  single thread tracing currently and just reads trace_pipe in text and then
21  write it to stdout.
22
23  'perf ftrace latency' calculates execution latency of a given function
24  (optionally with BPF) and display it as a histogram.
25
26  'perf ftrace profile' show a execution profile for each function including
27  total, average, max time and the number of calls.
28
29The following options apply to perf ftrace.
30
31COMMON OPTIONS
32--------------
33
34-p::
35--pid=::
36	Trace on existing process id (comma separated list).
37
38--tid=::
39	Trace on existing thread id (comma separated list).
40
41-a::
42--all-cpus::
43	Force system-wide collection.  Scripts run without a <command>
44	normally use -a by default, while scripts run with a <command>
45	normally don't - this option allows the latter to be run in
46	system-wide mode.
47
48-C::
49--cpu=::
50	Only trace for the list of CPUs provided.  Multiple CPUs can
51	be provided as a comma separated list with no space like: 0,1.
52	Ranges of CPUs are specified with -: 0-2.
53	Default is to trace on all online CPUs.
54
55-v::
56--verbose::
57        Increase the verbosity level.
58
59
60OPTIONS for 'perf ftrace trace'
61-------------------------------
62
63-t::
64--tracer=::
65	Tracer to use when neither -G nor -F option is not
66	specified: function_graph or function.
67
68-F::
69--funcs::
70        List available functions to trace. It accepts a pattern to
71        only list interested functions.
72
73-D::
74--delay::
75	Time (ms) to wait before starting tracing after program start.
76
77-m::
78--buffer-size::
79	Set the size of per-cpu tracing buffer, <size> is expected to
80	be a number with appended unit character - B/K/M/G.
81
82--inherit::
83	Trace children processes spawned by our target.
84
85-T::
86--trace-funcs=::
87	Select function tracer and set function filter on the given
88	function (or a glob pattern). Multiple functions can be given
89	by using this option more than once. The function argument also
90	can be a glob pattern. It will be passed to 'set_ftrace_filter'
91	in tracefs.
92
93-N::
94--notrace-funcs=::
95	Select function tracer and do not trace functions given by the
96	argument.  Like -T option, this can be used more than once to
97	specify multiple functions (or glob patterns).  It will be
98	passed to 'set_ftrace_notrace' in tracefs.
99
100--func-opts::
101	List of options allowed to set:
102
103	  - call-graph - Display kernel stack trace for function tracer.
104	  - irq-info   - Display irq context info for function tracer.
105
106-G::
107--graph-funcs=::
108	Select function_graph tracer and set graph filter on the given
109	function (or a glob pattern). This is useful to trace for
110	functions executed from the given function. This can be used more
111	than once to specify multiple functions. It will be passed to
112	'set_graph_function' in tracefs.
113
114-g::
115--nograph-funcs=::
116	Select function_graph tracer and set graph notrace filter on the
117	given function (or a glob pattern). Like -G option, this is useful
118	for the function_graph tracer only and disables tracing for function
119	executed from the given function. This can be used more than once to
120	specify multiple functions. It will be passed to 'set_graph_notrace'
121	in tracefs.
122
123--graph-opts::
124	List of options allowed to set:
125
126	  - args         - Show function arguments.
127	  - retval       - Show function return value.
128	  - retval-hex   - Show function return value in hexadecimal format.
129	  - retaddr      - Show function return address.
130	  - nosleep-time - Measure on-CPU time only for function_graph tracer.
131	  - noirqs       - Ignore functions that happen inside interrupt.
132	  - verbose      - Show process names, PIDs, timestamps, etc.
133	  - thresh=<n>   - Setup trace duration threshold in microseconds.
134	  - depth=<n>    - Set max depth for function graph tracer to follow.
135	  - tail         - Print function name at the end.
136
137
138OPTIONS for 'perf ftrace latency'
139---------------------------------
140
141-T::
142--trace-funcs=::
143	Set the function name to get the histogram.  Unlike perf ftrace trace,
144	it only allows single function to calculate the histogram.
145
146-e::
147--events=::
148	Set the pair of events to get the histogram.  The histogram is calculated
149	by the time difference between the two events from the same thread.  This
150	requires -b/--use-bpf option.
151
152-b::
153--use-bpf::
154	Use BPF to measure function latency instead of using the ftrace (it
155	uses function_graph tracer internally).
156
157-n::
158--use-nsec::
159	Use nano-second instead of micro-second as a base unit of the histogram.
160
161--bucket-range=::
162	Bucket range in ms or ns (according to -n/--use-nsec), default is log2() mode.
163
164--min-latency=::
165	Minimum latency for the start of the first bucket, in ms or ns (according to
166	-n/--use-nsec).
167
168--max-latency=::
169	Maximum latency for the start of the last bucket, in ms or ns (according to
170	-n/--use-nsec). The setting is ignored if the value results in more than
171	22 buckets.
172
173OPTIONS for 'perf ftrace profile'
174---------------------------------
175
176-T::
177--trace-funcs=::
178	Set function filter on the given function (or a glob pattern).
179	Multiple functions can be given by using this option more than once.
180	The function argument also can be a glob pattern. It will be passed
181	to 'set_ftrace_filter' in tracefs.
182
183-N::
184--notrace-funcs=::
185	Do not trace functions given by the argument.  Like -T option, this
186	can be used more than once to specify multiple functions (or glob
187	patterns).  It will be passed to 'set_ftrace_notrace' in tracefs.
188
189-G::
190--graph-funcs=::
191	Set graph filter on the given function (or a glob pattern). This is
192	useful to trace for functions executed from the given function. This
193	can be used more than once to specify multiple functions. It will be
194	passed to 'set_graph_function' in tracefs.
195
196-g::
197--nograph-funcs=::
198	Set graph notrace filter on the given function (or a glob pattern).
199	Like -G option, this is useful for the function_graph tracer only and
200	disables tracing for function executed from the given function. This
201	can be used more than once to specify multiple functions. It will be
202	passed to 'set_graph_notrace' in tracefs.
203
204-m::
205--buffer-size::
206	Set the size of per-cpu tracing buffer, <size> is expected to
207	be a number with appended unit character - B/K/M/G.
208
209-s::
210--sort=::
211	Sort the result by the given field.  Available values are:
212	total, avg, max, count, name.  Default is 'total'.
213
214--graph-opts::
215	List of options allowed to set:
216
217	  - nosleep-time - Measure on-CPU time only for function_graph tracer.
218	  - noirqs       - Ignore functions that happen inside interrupt.
219	  - thresh=<n>   - Setup trace duration threshold in microseconds.
220	  - depth=<n>    - Set max depth for function graph tracer to follow.
221
222
223SEE ALSO
224--------
225linkperf:perf-record[1], linkperf:perf-trace[1]
226