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	  - nosleep-time - Measure on-CPU time only for function_graph tracer.
127	  - noirqs       - Ignore functions that happen inside interrupt.
128	  - verbose      - Show process names, PIDs, timestamps, etc.
129	  - thresh=<n>   - Setup trace duration threshold in microseconds.
130	  - depth=<n>    - Set max depth for function graph tracer to follow.
131	  - tail         - Print function name at the end.
132
133
134OPTIONS for 'perf ftrace latency'
135---------------------------------
136
137-T::
138--trace-funcs=::
139	Set the function name to get the histogram.  Unlike perf ftrace trace,
140	it only allows single function to calculate the histogram.
141
142-b::
143--use-bpf::
144	Use BPF to measure function latency instead of using the ftrace (it
145	uses function_graph tracer internally).
146
147-n::
148--use-nsec::
149	Use nano-second instead of micro-second as a base unit of the histogram.
150
151--bucket-range=::
152	Bucket range in ms or ns (according to -n/--use-nsec), default is log2() mode.
153
154--min-latency=::
155	Minimum latency for the start of the first bucket, in ms or ns (according to
156	-n/--use-nsec).
157
158--max-latency=::
159	Maximum latency for the start of the last bucket, in ms or ns (according to
160	-n/--use-nsec). The setting is ignored if the value results in more than
161	22 buckets.
162
163OPTIONS for 'perf ftrace profile'
164---------------------------------
165
166-T::
167--trace-funcs=::
168	Set function filter on the given function (or a glob pattern).
169	Multiple functions can be given by using this option more than once.
170	The function argument also can be a glob pattern. It will be passed
171	to 'set_ftrace_filter' in tracefs.
172
173-N::
174--notrace-funcs=::
175	Do not trace functions given by the argument.  Like -T option, this
176	can be used more than once to specify multiple functions (or glob
177	patterns).  It will be passed to 'set_ftrace_notrace' in tracefs.
178
179-G::
180--graph-funcs=::
181	Set graph filter on the given function (or a glob pattern). This is
182	useful to trace for functions executed from the given function. This
183	can be used more than once to specify multiple functions. It will be
184	passed to 'set_graph_function' in tracefs.
185
186-g::
187--nograph-funcs=::
188	Set graph notrace filter on the given function (or a glob pattern).
189	Like -G option, this is useful for the function_graph tracer only and
190	disables tracing for function executed from the given function. This
191	can be used more than once to specify multiple functions. It will be
192	passed to 'set_graph_notrace' in tracefs.
193
194-m::
195--buffer-size::
196	Set the size of per-cpu tracing buffer, <size> is expected to
197	be a number with appended unit character - B/K/M/G.
198
199-s::
200--sort=::
201	Sort the result by the given field.  Available values are:
202	total, avg, max, count, name.  Default is 'total'.
203
204--graph-opts::
205	List of options allowed to set:
206
207	  - nosleep-time - Measure on-CPU time only for function_graph tracer.
208	  - noirqs       - Ignore functions that happen inside interrupt.
209	  - thresh=<n>   - Setup trace duration threshold in microseconds.
210	  - depth=<n>    - Set max depth for function graph tracer to follow.
211
212
213SEE ALSO
214--------
215linkperf:perf-record[1], linkperf:perf-trace[1]
216