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Masami Hiramatsu595c3642009-10-16 20:08:27 -04001perf-probe(1)
2=============
3
4NAME
5----
6perf-probe - Define new dynamic tracepoints
7
8SYNOPSIS
9--------
10[verse]
Masami Hiramatsuc937fe22009-12-08 17:03:30 -050011'perf probe' [options] --add='PROBE' [...]
Masami Hiramatsuc43f9d12009-11-03 19:12:13 -050012or
Masami Hiramatsuc937fe22009-12-08 17:03:30 -050013'perf probe' [options] PROBE
14or
15'perf probe' [options] --del='[GROUP:]EVENT' [...]
16or
17'perf probe' --list
Masami Hiramatsu631c9de2010-01-06 09:45:34 -050018or
Masami Hiramatsue116dfa2011-02-10 18:08:10 +090019'perf probe' [options] --line='LINE'
Masami Hiramatsucf6eb482010-10-21 19:13:23 +090020or
Masami Hiramatsu469b9b82010-10-21 19:13:41 +090021'perf probe' [options] --vars='PROBEPOINT'
Masami Hiramatsub3ac0322015-04-23 22:46:12 +090022or
23'perf probe' [options] --funcs
Masami Hiramatsu595c3642009-10-16 20:08:27 -040024
25DESCRIPTION
26-----------
27This command defines dynamic tracepoint events, by symbol and registers
28without debuginfo, or by C expressions (C line numbers, C function names,
29and C local variables) with debuginfo.
30
31
32OPTIONS
33-------
34-k::
Masami Hiramatsuc43f9d12009-11-03 19:12:13 -050035--vmlinux=PATH::
Masami Hiramatsu595c3642009-10-16 20:08:27 -040036 Specify vmlinux path which has debuginfo (Dwarf binary).
37
Masami Hiramatsu469b9b82010-10-21 19:13:41 +090038-m::
Masami Hiramatsu14a8fd72011-06-27 16:27:51 +090039--module=MODNAME|PATH::
Masami Hiramatsu469b9b82010-10-21 19:13:41 +090040 Specify module name in which perf-probe searches probe points
Masami Hiramatsu14a8fd72011-06-27 16:27:51 +090041 or lines. If a path of module file is passed, perf-probe
42 treat it as an offline module (this means you can add a probe on
43 a module which has not been loaded yet).
Masami Hiramatsu469b9b82010-10-21 19:13:41 +090044
Chase Douglas9ed7e1b2010-06-14 15:26:30 -040045-s::
46--source=PATH::
47 Specify path to kernel source.
48
Masami Hiramatsu595c3642009-10-16 20:08:27 -040049-v::
50--verbose::
51 Be more verbose (show parsed arguments, etc).
Masami Hiramatsu8b728052015-01-30 18:37:46 +090052 Can not use with -q.
53
54-q::
55--quiet::
56 Be quiet (do not show any messages including errors).
57 Can not use with -v.
Masami Hiramatsu595c3642009-10-16 20:08:27 -040058
Masami Hiramatsuc43f9d12009-11-03 19:12:13 -050059-a::
Masami Hiramatsuc937fe22009-12-08 17:03:30 -050060--add=::
61 Define a probe event (see PROBE SYNTAX for detail).
62
63-d::
64--del=::
Masami Hiramatsuee391de2010-02-25 08:35:19 -050065 Delete probe events. This accepts glob wildcards('*', '?') and character
66 classes(e.g. [a-z], [!A-Z]).
Masami Hiramatsuc937fe22009-12-08 17:03:30 -050067
68-l::
69--list::
70 List up current probe events.
Masami Hiramatsu595c3642009-10-16 20:08:27 -040071
Masami Hiramatsu631c9de2010-01-06 09:45:34 -050072-L::
73--line=::
74 Show source code lines which can be probed. This needs an argument
Masami Hiramatsuee391de2010-02-25 08:35:19 -050075 which specifies a range of the source code. (see LINE SYNTAX for detail)
76
Masami Hiramatsucf6eb482010-10-21 19:13:23 +090077-V::
78--vars=::
79 Show available local variables at given probe point. The argument
80 syntax is same as PROBE SYNTAX, but NO ARGs.
81
Masami Hiramatsufb8c5a52010-10-21 19:13:35 +090082--externs::
83 (Only for --vars) Show external defined variables in addition to local
84 variables.
85
Masami Hiramatsue80711c2011-01-13 21:46:11 +090086-F::
87--funcs::
Srikar Dronamraju225466f2012-04-16 17:39:09 +053088 Show available functions in given module or kernel. With -x/--exec,
89 can also list functions in a user space executable / shared library.
Masami Hiramatsue80711c2011-01-13 21:46:11 +090090
Masami Hiramatsubd09d7b2011-01-20 23:15:39 +090091--filter=FILTER::
Masami Hiramatsu3c422582011-01-20 23:15:45 +090092 (Only for --vars and --funcs) Set filter. FILTER is a combination of glob
93 pattern, see FILTER PATTERN for detail.
94 Default FILTER is "!__k???tab_* & !__crc_*" for --vars, and "!_*"
95 for --funcs.
96 If several filters are specified, only the last filter is used.
Masami Hiramatsubd09d7b2011-01-20 23:15:39 +090097
Masami Hiramatsuee391de2010-02-25 08:35:19 -050098-f::
99--force::
100 Forcibly add events with existing name.
Masami Hiramatsu631c9de2010-01-06 09:45:34 -0500101
Masami Hiramatsuf4d7da42010-03-16 18:06:05 -0400102-n::
103--dry-run::
104 Dry run. With this option, --add and --del doesn't execute actual
105 adding and removal operations.
106
Masami Hiramatsu8b728052015-01-30 18:37:46 +0900107--max-probes=NUM::
Masami Hiramatsuef4a3562010-04-21 15:56:40 -0400108 Set the maximum number of probe points for an event. Default is 128.
109
Srikar Dronamraju225466f2012-04-16 17:39:09 +0530110-x::
111--exec=PATH::
112 Specify path to the executable or shared library file for user
113 space tracing. Can also be used with --funcs option.
114
Masami Hiramatsu8b728052015-01-30 18:37:46 +0900115--demangle::
116 Demangle application symbols. --no-demangle is also available
117 for disabling demangling.
118
Avi Kivity763122a2014-09-13 07:15:05 +0300119--demangle-kernel::
Masami Hiramatsu8b728052015-01-30 18:37:46 +0900120 Demangle kernel symbols. --no-demangle-kernel is also available
121 for disabling kernel demangling.
Avi Kivity763122a2014-09-13 07:15:05 +0300122
Srikar Dronamraju73eff9f2012-04-16 17:39:25 +0530123In absence of -m/-x options, perf probe checks if the first argument after
124the options is an absolute path name. If its an absolute path, perf probe
125uses it as a target module/target user space binary to probe.
126
Masami Hiramatsu595c3642009-10-16 20:08:27 -0400127PROBE SYNTAX
128------------
129Probe points are defined by following syntax.
130
Masami Hiramatsu2a9c8c32010-02-25 08:36:12 -0500131 1) Define event based on function name
132 [EVENT=]FUNC[@SRC][:RLN|+OFFS|%return|;PTN] [ARG ...]
133
134 2) Define event based on source file with line number
135 [EVENT=]SRC:ALN [ARG ...]
136
137 3) Define event based on source file with lazy pattern
138 [EVENT=]SRC;PTN [ARG ...]
139
Masami Hiramatsu595c3642009-10-16 20:08:27 -0400140
Masami Hiramatsuaf663d72009-12-15 10:32:18 -0500141'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. Currently, event group name is set as 'probe'.
Masami Hiramatsu2a9c8c32010-02-25 08:36:12 -0500142'FUNC' specifies a probed function name, and it may have one of the following options; '+OFFS' is the offset from function entry address in bytes, ':RLN' is the relative-line number from function entry line, and '%return' means that it probes function return. And ';PTN' means lazy matching pattern (see LAZY MATCHING). Note that ';PTN' must be the end of the probe point definition. In addition, '@SRC' specifies a source file which has that function.
143It is also possible to specify a probe point by the source line number or lazy matching by using 'SRC:ALN' or 'SRC;PTN' syntax, where 'SRC' is the source file path, ':ALN' is the line number and ';PTN' is the lazy matching pattern.
Masami Hiramatsu48481932010-04-12 13:16:53 -0400144'ARG' specifies the arguments of this probe point, (see PROBE ARGUMENT).
145
146PROBE ARGUMENT
147--------------
148Each probe argument follows below syntax.
149
Masami Hiramatsu11a1ca32010-04-12 13:17:22 -0400150 [NAME=]LOCALVAR|$retval|%REG|@SYMBOL[:TYPE]
Masami Hiramatsu48481932010-04-12 13:16:53 -0400151
Masami Hiramatsub2a3c122010-05-19 15:57:42 -0400152'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), local array with fixed index (e.g. array[1], var->array[0], var->pointer[2]), or kprobe-tracer argument format (e.g. $retval, %ax, etc). Note that the name of this argument will be set as the last member name if you specify a local data structure member (e.g. field2 for 'var->field1.field2'.)
Masami Hiramatsu8b728052015-01-30 18:37:46 +0900153'$vars' special argument is also available for NAME, it is expanded to the local variables which can access at given probe point.
Masami Hiramatsu73317b92010-05-19 15:57:35 -0400154'TYPE' casts the type of this argument (optional). If omitted, perf probe automatically set the type based on debuginfo. You can specify 'string' type only for the local variable or structure member which is an array of or a pointer to 'char' or 'unsigned char' type.
Masami Hiramatsu595c3642009-10-16 20:08:27 -0400155
Andi Kleen5b439822014-02-28 06:02:15 -0800156On x86 systems %REG is always the short form of the register: for example %AX. %RAX or %EAX is not valid.
157
Masami Hiramatsu631c9de2010-01-06 09:45:34 -0500158LINE SYNTAX
159-----------
Shawn Bohrer9d5b7f52010-11-30 19:57:15 -0600160Line range is described by following syntax.
Masami Hiramatsu631c9de2010-01-06 09:45:34 -0500161
Masami Hiramatsue116dfa2011-02-10 18:08:10 +0900162 "FUNC[@SRC][:RLN[+NUM|-RLN2]]|SRC[:ALN[+NUM|-ALN2]]"
Masami Hiramatsu631c9de2010-01-06 09:45:34 -0500163
164FUNC specifies the function name of showing lines. 'RLN' is the start line
165number from function entry line, and 'RLN2' is the end line number. As same as
166probe syntax, 'SRC' means the source file path, 'ALN' is start line number,
167and 'ALN2' is end line number in the file. It is also possible to specify how
Masami Hiramatsue116dfa2011-02-10 18:08:10 +0900168many lines to show by using 'NUM'. Moreover, 'FUNC@SRC' combination is good
169for searching a specific function when several functions share same name.
Masami Hiramatsu631c9de2010-01-06 09:45:34 -0500170So, "source.c:100-120" shows lines between 100th to l20th in source.c file. And "func:10+20" shows 20 lines from 10th line of func function.
171
Masami Hiramatsu2a9c8c32010-02-25 08:36:12 -0500172LAZY MATCHING
173-------------
174 The lazy line matching is similar to glob matching but ignoring spaces in both of pattern and target. So this accepts wildcards('*', '?') and character classes(e.g. [a-z], [!A-Z]).
175
176e.g.
177 'a=*' can matches 'a=b', 'a = b', 'a == b' and so on.
178
179This provides some sort of flexibility and robustness to probe point definitions against minor code changes. For example, actual 10th line of schedule() can be moved easily by modifying schedule(), but the same line matching 'rq=cpu_rq*' may still exist in the function.)
180
Masami Hiramatsubd09d7b2011-01-20 23:15:39 +0900181FILTER PATTERN
182--------------
183 The filter pattern is a glob matching pattern(s) to filter variables.
184 In addition, you can use "!" for specifying filter-out rule. You also can give several rules combined with "&" or "|", and fold those rules as one rule by using "(" ")".
185
186e.g.
187 With --filter "foo* | bar*", perf probe -V shows variables which start with "foo" or "bar".
188 With --filter "!foo* & *bar", perf probe -V shows variables which don't start with "foo" and end with "bar", like "fizzbar". But "foobar" is filtered out.
Masami Hiramatsu2a9c8c32010-02-25 08:36:12 -0500189
Masami Hiramatsuee391de2010-02-25 08:35:19 -0500190EXAMPLES
191--------
192Display which lines in schedule() can be probed:
193
194 ./perf probe --line schedule
195
196Add a probe on schedule() function 12th line with recording cpu local variable:
197
198 ./perf probe schedule:12 cpu
199 or
200 ./perf probe --add='schedule:12 cpu'
201
202 this will add one or more probes which has the name start with "schedule".
203
Masami Hiramatsu2a9c8c32010-02-25 08:36:12 -0500204 Add probes on lines in schedule() function which calls update_rq_clock().
205
206 ./perf probe 'schedule;update_rq_clock*'
207 or
208 ./perf probe --add='schedule;update_rq_clock*'
209
Masami Hiramatsuee391de2010-02-25 08:35:19 -0500210Delete all probes on schedule().
211
212 ./perf probe --del='schedule*'
213
Srikar Dronamraju225466f2012-04-16 17:39:09 +0530214Add probes at zfree() function on /bin/zsh
215
Srikar Dronamraju73eff9f2012-04-16 17:39:25 +0530216 ./perf probe -x /bin/zsh zfree or ./perf probe /bin/zsh zfree
Srikar Dronamraju225466f2012-04-16 17:39:09 +0530217
218Add probes at malloc() function on libc
219
Srikar Dronamraju73eff9f2012-04-16 17:39:25 +0530220 ./perf probe -x /lib/libc.so.6 malloc or ./perf probe /lib/libc.so.6 malloc
Masami Hiramatsuee391de2010-02-25 08:35:19 -0500221
Masami Hiramatsu595c3642009-10-16 20:08:27 -0400222SEE ALSO
223--------
224linkperf:perf-trace[1], linkperf:perf-record[1]