xref: /openbmc/linux/tools/perf/Documentation/perf-record.txt (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
1perf-record(1)
2==============
3
4NAME
5----
6perf-record - Run a command and record its profile into perf.data
7
8SYNOPSIS
9--------
10[verse]
11'perf record' [-e <EVENT> | --event=EVENT] [-l] [-a] <command>
12'perf record' [-e <EVENT> | --event=EVENT] [-l] [-a] -- <command> [<options>]
13
14DESCRIPTION
15-----------
16This command runs a command and gathers a performance counter profile
17from it, into perf.data - without displaying anything.
18
19This file can then be inspected later on, using 'perf report'.
20
21
22OPTIONS
23-------
24<command>...::
25	Any command you can specify in a shell.
26
27-e::
28--event=::
29	Select the PMU event. Selection can be:
30
31        - a symbolic event name	(use 'perf list' to list all events)
32
33        - a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
34	  hexadecimal event descriptor.
35
36	- a symbolically formed PMU event like 'pmu/param1=0x3,param2/' where
37	  'param1', 'param2', etc are defined as formats for the PMU in
38	  /sys/bus/event_sources/devices/<pmu>/format/*.
39
40	- a symbolically formed event like 'pmu/config=M,config1=N,config3=K/'
41
42          where M, N, K are numbers (in decimal, hex, octal format). Acceptable
43          values for each of 'config', 'config1' and 'config2' are defined by
44          corresponding entries in /sys/bus/event_sources/devices/<pmu>/format/*
45          param1 and param2 are defined as formats for the PMU in:
46          /sys/bus/event_sources/devices/<pmu>/format/*
47
48        - a hardware breakpoint event in the form of '\mem:addr[/len][:access]'
49          where addr is the address in memory you want to break in.
50          Access is the memory access type (read, write, execute) it can
51          be passed as follows: '\mem:addr[:[r][w][x]]'. len is the range,
52          number of bytes from specified addr, which the breakpoint will cover.
53          If you want to profile read-write accesses in 0x1000, just set
54          'mem:0x1000:rw'.
55          If you want to profile write accesses in [0x1000~1008), just set
56          'mem:0x1000/8:w'.
57
58	- a group of events surrounded by a pair of brace ("{event1,event2,...}").
59	  Each event is separated by commas and the group should be quoted to
60	  prevent the shell interpretation.  You also need to use --group on
61	  "perf report" to view group events together.
62
63--filter=<filter>::
64        Event filter.
65
66-a::
67--all-cpus::
68        System-wide collection from all CPUs.
69
70-p::
71--pid=::
72	Record events on existing process ID (comma separated list).
73
74-t::
75--tid=::
76        Record events on existing thread ID (comma separated list).
77        This option also disables inheritance by default.  Enable it by adding
78        --inherit.
79
80-u::
81--uid=::
82        Record events in threads owned by uid. Name or number.
83
84-r::
85--realtime=::
86	Collect data with this RT SCHED_FIFO priority.
87
88--no-buffering::
89	Collect data without buffering.
90
91-c::
92--count=::
93	Event period to sample.
94
95-o::
96--output=::
97	Output file name.
98
99-i::
100--no-inherit::
101	Child tasks do not inherit counters.
102-F::
103--freq=::
104	Profile at this frequency.
105
106-m::
107--mmap-pages=::
108	Number of mmap data pages (must be a power of two) or size
109	specification with appended unit character - B/K/M/G. The
110	size is rounded up to have nearest pages power of two value.
111	Also, by adding a comma, the number of mmap pages for AUX
112	area tracing can be specified.
113
114--group::
115	Put all events in a single event group.  This precedes the --event
116	option and remains only for backward compatibility.  See --event.
117
118-g::
119	Enables call-graph (stack chain/backtrace) recording.
120
121--call-graph::
122	Setup and enable call-graph (stack chain/backtrace) recording,
123	implies -g.
124
125	Allows specifying "fp" (frame pointer) or "dwarf"
126	(DWARF's CFI - Call Frame Information) or "lbr"
127	(Hardware Last Branch Record facility) as the method to collect
128	the information used to show the call graphs.
129
130	In some systems, where binaries are build with gcc
131	--fomit-frame-pointer, using the "fp" method will produce bogus
132	call graphs, using "dwarf", if available (perf tools linked to
133	the libunwind library) should be used instead.
134	Using the "lbr" method doesn't require any compiler options. It
135	will produce call graphs from the hardware LBR registers. The
136	main limition is that it is only available on new Intel
137	platforms, such as Haswell. It can only get user call chain. It
138	doesn't work with branch stack sampling at the same time.
139
140-q::
141--quiet::
142	Don't print any message, useful for scripting.
143
144-v::
145--verbose::
146	Be more verbose (show counter open errors, etc).
147
148-s::
149--stat::
150	Record per-thread event counts.  Use it with 'perf report -T' to see
151	the values.
152
153-d::
154--data::
155	Record the sample addresses.
156
157-T::
158--timestamp::
159	Record the sample timestamps. Use it with 'perf report -D' to see the
160	timestamps, for instance.
161
162-P::
163--period::
164	Record the sample period.
165
166-n::
167--no-samples::
168	Don't sample.
169
170-R::
171--raw-samples::
172Collect raw sample records from all opened counters (default for tracepoint counters).
173
174-C::
175--cpu::
176Collect samples only on the list of CPUs provided. Multiple CPUs can be provided as a
177comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
178In per-thread mode with inheritance mode on (default), samples are captured only when
179the thread executes on the designated CPUs. Default is to monitor all CPUs.
180
181-N::
182--no-buildid-cache::
183Do not update the buildid cache. This saves some overhead in situations
184where the information in the perf.data file (which includes buildids)
185is sufficient.
186
187-G name,...::
188--cgroup name,...::
189monitor only in the container (cgroup) called "name". This option is available only
190in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
191container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
192can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
193to first event, second cgroup to second event and so on. It is possible to provide
194an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
195corresponding events, i.e., they always refer to events defined earlier on the command
196line.
197
198-b::
199--branch-any::
200Enable taken branch stack sampling. Any type of taken branch may be sampled.
201This is a shortcut for --branch-filter any. See --branch-filter for more infos.
202
203-j::
204--branch-filter::
205Enable taken branch stack sampling. Each sample captures a series of consecutive
206taken branches. The number of branches captured with each sample depends on the
207underlying hardware, the type of branches of interest, and the executed code.
208It is possible to select the types of branches captured by enabling filters. The
209following filters are defined:
210
211        - any:  any type of branches
212        - any_call: any function call or system call
213        - any_ret: any function return or system call return
214        - ind_call: any indirect branch
215        - u:  only when the branch target is at the user level
216        - k: only when the branch target is in the kernel
217        - hv: only when the target is at the hypervisor level
218	- in_tx: only when the target is in a hardware transaction
219	- no_tx: only when the target is not in a hardware transaction
220	- abort_tx: only when the target is a hardware transaction abort
221	- cond: conditional branches
222
223+
224The option requires at least one branch type among any, any_call, any_ret, ind_call, cond.
225The privilege levels may be omitted, in which case, the privilege levels of the associated
226event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege
227levels are subject to permissions.  When sampling on multiple events, branch stack sampling
228is enabled for all the sampling events. The sampled branch type is the same for all events.
229The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k
230Note that this feature may not be available on all processors.
231
232--weight::
233Enable weightened sampling. An additional weight is recorded per sample and can be
234displayed with the weight and local_weight sort keys.  This currently works for TSX
235abort events and some memory events in precise mode on modern Intel CPUs.
236
237--transaction::
238Record transaction flags for transaction related events.
239
240--per-thread::
241Use per-thread mmaps.  By default per-cpu mmaps are created.  This option
242overrides that and uses per-thread mmaps.  A side-effect of that is that
243inheritance is automatically disabled.  --per-thread is ignored with a warning
244if combined with -a or -C options.
245
246-D::
247--delay=::
248After starting the program, wait msecs before measuring. This is useful to
249filter out the startup phase of the program, which is often very different.
250
251-I::
252--intr-regs::
253Capture machine state (registers) at interrupt, i.e., on counter overflows for
254each sample. List of captured registers depends on the architecture. This option
255is off by default.
256
257--running-time::
258Record running and enabled time for read events (:S)
259
260-k::
261--clockid::
262Sets the clock id to use for the various time fields in the perf_event_type
263records. See clock_gettime(). In particular CLOCK_MONOTONIC and
264CLOCK_MONOTONIC_RAW are supported, some events might also allow
265CLOCK_BOOTTIME, CLOCK_REALTIME and CLOCK_TAI.
266
267-S::
268--snapshot::
269Select AUX area tracing Snapshot Mode. This option is valid only with an
270AUX area tracing event. Optionally the number of bytes to capture per
271snapshot can be specified. In Snapshot Mode, trace data is captured only when
272signal SIGUSR2 is received.
273
274--proc-map-timeout::
275When processing pre-existing threads /proc/XXX/mmap, it may take a long time,
276because the file may be huge. A time out is needed in such cases.
277This option sets the time out limit. The default value is 500 ms.
278
279SEE ALSO
280--------
281linkperf:perf-stat[1], linkperf:perf-list[1]
282