1 perf-trace(1)
2 =============
3
4 NAME
5 ----
6 perf-trace - strace inspired tool
7
8 SYNOPSIS
9 --------
10 [verse]
11 'perf trace'
12 'perf trace record'
13
14 DESCRIPTION
15 -----------
16 This command will show the events associated w
17 syscalls, but other system events like pagefau
18 scheduling events, etc.
19
20 This is a live mode tool in addition to workin
21 the other perf tools. Files can be generated u
22 but the session needs to include the raw_sysca
23 Alternatively, 'perf trace record' can be used
24 automatically include the raw_syscalls events
25
26 The following options apply to perf trace; opt
27 found in the perf record man page.
28
29 OPTIONS
30 -------
31
32 -a::
33 --all-cpus::
34 System-wide collection from all CPUs.
35
36 -e::
37 --expr::
38 --event::
39 List of syscalls and other perf events
40 etc) to show. Globbing is supported, e
41 See 'perf list' for a complete list of
42 Prefixing with ! shows all syscalls bu
43 need to escape it.
44
45 --filter=<filter>::
46 Event filter. This option should follo
47 selects tracepoint event(s).
48
49
50 -D msecs::
51 --delay msecs::
52 After starting the program, wait msecs before
53 filter out the startup phase of the program, w
54
55 -o::
56 --output=::
57 Output file name.
58
59 -p::
60 --pid=::
61 Record events on existing process ID (
62
63 -t::
64 --tid=::
65 Record events on existing thread ID (c
66
67 -u::
68 --uid=::
69 Record events in threads owned by uid.
70
71 -G::
72 --cgroup::
73 Record events in threads in a cgroup.
74
75 Look for cgroups to set at the /sys/fs
76 remove the /sys/fs/cgroup/perf_event/
77
78 perf trace -G A -e sched:*swit
79
80 Will set all raw_syscalls:sys_{enter,e
81 _and_ sched:sched_switch to the 'A' cg
82
83 perf trace -e sched:*switch -G
84
85 will only set the sched:sched_switch e
86 other events (raw_syscalls:sys_{enter,
87 a cgroup (on the root cgroup, sys wide
88
89 Multiple cgroups:
90
91 perf trace -G A -e sched:*swit
92
93 the syscall ones go to the 'A' cgroup,
94 to the 'B' cgroup.
95
96 --filter-pids=::
97 Filter out events for these pids and f
98
99 -v::
100 --verbose::
101 Increase the verbosity level.
102
103 --no-inherit::
104 Child tasks do not inherit counters.
105
106 -m::
107 --mmap-pages=::
108 Number of mmap data pages (must be a p
109 specification in bytes with appended u
110 The size is rounded up to the nearest
111
112 -C::
113 --cpu::
114 Collect samples only on the list of CPUs provi
115 comma-separated list with no space: 0,1. Range
116 In per-thread mode with inheritance mode on (d
117 the thread executes on the designated CPUs. De
118
119 --duration::
120 Show only events that had a duration g
121
122 --sched::
123 Accrue thread runtime and provide a su
124
125 --failure::
126 Show only syscalls that failed, i.e. t
127
128 -i::
129 --input::
130 Process events from a given perf data
131
132 -T::
133 --time::
134 Print full timestamp rather time relat
135
136 --comm::
137 Show process COMM right beside its ID,
138
139 -s::
140 --summary::
141 Show only a summary of syscalls by thr
142 (in msec) and relative stddev.
143
144 -S::
145 --with-summary::
146 Show all syscalls followed by a summar
147 average times (in msec) and relative stdde
148
149 --errno-summary::
150 To be used with -s or -S, to show stat
151 syscalls, using only this option will
152
153 --tool_stats::
154 Show tool stats such as number of time
155 hooking the open syscall return + vfs_
156
157 -f::
158 --force::
159 Don't complain, do it.
160
161 -F=[all|min|maj]::
162 --pf=[all|min|maj]::
163 Trace pagefaults. Optionally, you can
164 major or all pagefaults. Default value
165
166 --syscalls::
167 Trace system calls. This options is en
168 --no-syscalls.
169
170 --call-graph [mode,type,min[,limit],order[,key
171 Setup and enable call-graph (stack cha
172 See `--call-graph` section in perf-rec
173 man pages for details. The ones that a
174 are 'dwarf' and 'lbr', where available
175
176 Using this will, for the root user, bu
177 times the maximum for non-root users,
178 sysctl. This is done only if the user
179
180 --kernel-syscall-graph::
181 Show the kernel callchains on the sys
182
183 --max-events=N::
184 Stop after processing N events. Note t
185 only at exit time or when a syscall is
186 option is equivalent to the number of
187
188 --switch-on EVENT_NAME::
189 Only consider events after this event
190
191 --switch-off EVENT_NAME::
192 Stop considering events after this eve
193
194 --show-on-off-events::
195 Show the --switch-on/off events too.
196
197 --max-stack::
198 Set the stack depth limit when parsing
199 beyond the specified depth will be ign
200 this is just about the presentation pa
201 not limiting, the overhead of callchai
202 knobs in --call-graph dwarf.
203
204 Implies '--call-graph dwarf' when --ca
205 command line, on systems where DWARF u
206
207 Default: /proc/sys/kernel/perf_event_m
208 live sessions (without --inpu
209
210 --min-stack::
211 Set the stack depth limit when parsing
212 below the specified depth will be igno
213
214 Implies '--call-graph dwarf' when --ca
215 command line, on systems where DWARF u
216
217 --print-sample::
218 Print the PERF_RECORD_SAMPLE PERF_SAMP
219 raw_syscalls:sys_{enter,exit} tracepoi
220
221 --proc-map-timeout::
222 When processing pre-existing threads /
223 because the file may be huge. A time o
224 This option sets the time out limit. T
225
226 --sort-events::
227 Do sorting on batches of events, use w
228 may happen, for instance, when a threa
229 while processing a syscall.
230
231 --libtraceevent_print::
232 Use libtraceevent to print tracepoint
233 the same beautifiers used in the strac
234 tracepoint arguments.
235
236 --map-dump::
237 Dump BPF maps setup by events passed v
238 living in tools/perf/examples/bpf/augm
239 dumps just boolean map values and inte
240 by default and use BTF when available,
241 printing using the existing 'perf trac
242 arguments to strings (pid to comm, sys
243
244
245 PAGEFAULTS
246 ----------
247
248 When tracing pagefaults, the format of the tra
249
250 <min|maj>fault [<ip.symbol>+<ip.offset>] => <ad
251
252 - min/maj indicates whether fault event is min
253 - ip.symbol shows symbol for instruction point
254 fault); if no debug symbols available, perf
255 - addr.dso shows DSO for the faulted address;
256 - map type is either 'd' for non-executable ma
257 - addr level is either 'k' for kernel dso or '
258
259 For symbols resolution you may need to install
260
261 Please be aware that duration is currently alw
262 time it took for fault to be handled!
263
264 When --verbose specified, perf trace tries to
265 for both IP and fault address in the form of d
266
267 EXAMPLES
268 --------
269
270 Trace only major pagefaults:
271
272 $ perf trace --no-syscalls -F
273
274 Trace syscalls, major and minor pagefaults:
275
276 $ perf trace -F all
277
278 1416.547 ( 0.000 ms): python/20235 majfault
279
280 As you can see, there was major pagefault in
281 CRYPTO_push_info_ routine which faulted some
282
283 Trace the first 4 open, openat or open_by_hand
284
285 $ perf trace -e open* --max-events 4
286 [root@jouet perf]# trace -e open* --max-even
287 2272.992 ( 0.037 ms): gnome-shell/1370 opena
288 2277.481 ( 0.139 ms): gnome-shell/3039 opena
289 3026.398 ( 0.076 ms): gnome-shell/3039 opena
290 4294.665 ( 0.015 ms): sed/15879 openat(dfd:
291 $
292
293 Trace the first minor page fault when running
294
295 # perf trace -F min --max-stack=7 --max-even
296 0.000 ( 0.000 ms): sleep/18006 minfault [
297 __clear
298 load_el
299 search_
300 __do_ex
301 __x64_s
302 do_sysc
303 entry_S
304 #
305
306 Trace the next min page page fault to take pla
307
308 # perf trace -F min --call-graph=dwarf --max
309 0.000 ( 0.000 ms): Web Content/17136 minf
310 js::gc:
311 js::gc:
312 js::gc:
313 js::gc:
314 js::gc:
315 js::gc:
316 js::gc:
317 js::All
318 js::All
319 JSThinI
320 Allocat
321 js::Con
322 [0x18b2
323 #
324
325 Trace the next two sched:sched_switch events,
326 next block:*_unplug and the next three net:*de
327 with a backtrace of at most 16 entries, system
328
329 # perf trace -e sched:*switch/nr=2/,block:*_
330 0.000 :0/0 sched:sched_switch:swapper/2:0
331 0.015 rcu_sched/10 sched:sched_switch:rcu
332 254.198 irq/50-iwlwifi/680 net:net_dev_queu
333 __dev_q
334 273.977 :0/0 net:net_dev_queue:dev=wlp3s0 s
335 __dev_q
336 274.007 :0/0 net:net_dev_queue:dev=wlp3s0 s
337 __dev_q
338 2930.140 kworker/u16:58/2722 block:block_plu
339 2930.162 kworker/u16:58/2722 block:block_unp
340 4466.094 jbd2/dm-2-8/748 block:block_plug:[j
341 8050.123 kworker/u16:30/2694 block:block_plu
342 8050.271 kworker/u16:30/2694 block:block_plu
343 #
344
345 SEE ALSO
346 --------
347 linkperf:perf-record[1], linkperf:perf-script[
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