1 perf-top(1) 1 perf-top(1)
2 =========== 2 ===========
3 3
4 NAME 4 NAME
5 ---- 5 ----
6 perf-top - System profiling tool. 6 perf-top - System profiling tool.
7 7
8 SYNOPSIS 8 SYNOPSIS
9 -------- 9 --------
10 [verse] 10 [verse]
11 'perf top' [-e <EVENT> | --event=EVENT] [<opti 11 'perf top' [-e <EVENT> | --event=EVENT] [<options>]
12 12
13 DESCRIPTION 13 DESCRIPTION
14 ----------- 14 -----------
15 This command generates and displays a performa 15 This command generates and displays a performance counter profile in real time.
16 16
17 17
18 OPTIONS 18 OPTIONS
19 ------- 19 -------
20 -a:: 20 -a::
21 --all-cpus:: 21 --all-cpus::
22 System-wide collection. (default) 22 System-wide collection. (default)
23 23
24 -c <count>:: 24 -c <count>::
25 --count=<count>:: 25 --count=<count>::
26 Event period to sample. 26 Event period to sample.
27 27
28 -C <cpu-list>:: 28 -C <cpu-list>::
29 --cpu=<cpu>:: 29 --cpu=<cpu>::
30 Monitor only on the list of CPUs provided. Mul 30 Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a
31 comma-separated list with no space: 0,1. Range 31 comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
32 Default is to monitor all CPUS. 32 Default is to monitor all CPUS.
33 33
34 -d <seconds>:: 34 -d <seconds>::
35 --delay=<seconds>:: 35 --delay=<seconds>::
36 Number of seconds to delay between ref 36 Number of seconds to delay between refreshes.
37 37
38 -e <event>:: 38 -e <event>::
39 --event=<event>:: 39 --event=<event>::
40 Select the PMU event. Selection can be 40 Select the PMU event. Selection can be a symbolic event name
41 (use 'perf list' to list all events) o !! 41 (use 'perf list' to list all events) or a raw PMU
42 of rN where N is a hexadecimal value t !! 42 event (eventsel+umask) in the form of rNNN where NNN is a
43 encoding with the layout of the event !! 43 hexadecimal event descriptor.
44 by entries in /sys/bus/event_source/de <<
45 <<
46 --filter=<filter>:: <<
47 Event filter. This option should foll <<
48 syntax see linkperf:perf-record[1]. <<
49 44
50 -E <entries>:: 45 -E <entries>::
51 --entries=<entries>:: 46 --entries=<entries>::
52 Display this many functions. 47 Display this many functions.
53 48
54 -f <count>:: 49 -f <count>::
55 --count-filter=<count>:: 50 --count-filter=<count>::
56 Only display functions with more event 51 Only display functions with more events than this.
57 52
58 --group-sort-idx:: !! 53 --group::
59 Sort the output by the event at the in !! 54 Put the counters into a counter group.
60 sort by the first event. It can suppor <<
61 amount of events. WARNING: This should <<
62 55
63 -F <freq>:: 56 -F <freq>::
64 --freq=<freq>:: 57 --freq=<freq>::
65 Profile at this frequency. Use 'max' t 58 Profile at this frequency. Use 'max' to use the currently maximum
66 allowed frequency, i.e. the value in t 59 allowed frequency, i.e. the value in the kernel.perf_event_max_sample_rate
67 sysctl. 60 sysctl.
68 61
69 -i:: 62 -i::
70 --inherit:: 63 --inherit::
71 Child tasks do not inherit counters. 64 Child tasks do not inherit counters.
72 65
73 -k <path>:: 66 -k <path>::
74 --vmlinux=<path>:: 67 --vmlinux=<path>::
75 Path to vmlinux. Required for annotat 68 Path to vmlinux. Required for annotation functionality.
76 69
77 --ignore-vmlinux:: 70 --ignore-vmlinux::
78 Ignore vmlinux files. 71 Ignore vmlinux files.
79 72
80 --kallsyms=<file>:: <<
81 kallsyms pathname <<
82 <<
83 -m <pages>:: 73 -m <pages>::
84 --mmap-pages=<pages>:: 74 --mmap-pages=<pages>::
85 Number of mmap data pages (must be a p 75 Number of mmap data pages (must be a power of two) or size
86 specification in bytes with appended u !! 76 specification with appended unit character - B/K/M/G. The
87 The size is rounded up to the nearest !! 77 size is rounded up to have nearest pages power of two value.
88 78
89 -p <pid>:: 79 -p <pid>::
90 --pid=<pid>:: 80 --pid=<pid>::
91 Profile events on existing Process ID 81 Profile events on existing Process ID (comma separated list).
92 82
93 -t <tid>:: 83 -t <tid>::
94 --tid=<tid>:: 84 --tid=<tid>::
95 Profile events on existing thread ID ( 85 Profile events on existing thread ID (comma separated list).
96 86
97 -u:: 87 -u::
98 --uid=:: 88 --uid=::
99 Record events in threads owned by uid. 89 Record events in threads owned by uid. Name or number.
100 90
101 -r <priority>:: 91 -r <priority>::
102 --realtime=<priority>:: 92 --realtime=<priority>::
103 Collect data with this RT SCHED_FIFO p 93 Collect data with this RT SCHED_FIFO priority.
104 94
105 --sym-annotate=<symbol>:: 95 --sym-annotate=<symbol>::
106 Annotate this symbol. 96 Annotate this symbol.
107 97
108 -K:: 98 -K::
109 --hide_kernel_symbols:: 99 --hide_kernel_symbols::
110 Hide kernel symbols. 100 Hide kernel symbols.
111 101
112 -U:: 102 -U::
113 --hide_user_symbols:: 103 --hide_user_symbols::
114 Hide user symbols. 104 Hide user symbols.
115 105
116 --demangle-kernel:: 106 --demangle-kernel::
117 Demangle kernel symbols. 107 Demangle kernel symbols.
118 108
119 -D:: 109 -D::
120 --dump-symtab:: 110 --dump-symtab::
121 Dump the symbol table used for profili 111 Dump the symbol table used for profiling.
122 112
123 -v:: 113 -v::
124 --verbose:: 114 --verbose::
125 Be more verbose (show counter open err 115 Be more verbose (show counter open errors, etc).
126 116
127 -z:: 117 -z::
128 --zero:: 118 --zero::
129 Zero history across display updates. 119 Zero history across display updates.
130 120
131 -s:: 121 -s::
132 --sort:: 122 --sort::
133 Sort by key(s): pid, comm, dso, symbol 123 Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight,
134 local_weight, abort, in_tx, transactio 124 local_weight, abort, in_tx, transaction, overhead, sample, period.
135 Please see description of --sort in th 125 Please see description of --sort in the perf-report man page.
136 126
137 --fields=:: 127 --fields=::
138 Specify output field - multiple keys c 128 Specify output field - multiple keys can be specified in CSV format.
139 Following fields are available: 129 Following fields are available:
140 overhead, overhead_sys, overhead_us, o 130 overhead, overhead_sys, overhead_us, overhead_children, sample and period.
141 Also it can contain any sort key(s). 131 Also it can contain any sort key(s).
142 132
143 By default, every sort keys not specif 133 By default, every sort keys not specified in --field will be appended
144 automatically. 134 automatically.
145 135
146 -n:: 136 -n::
147 --show-nr-samples:: 137 --show-nr-samples::
148 Show a column with the number of sampl 138 Show a column with the number of samples.
149 139
150 --show-total-period:: 140 --show-total-period::
151 Show a column with the sum of periods. 141 Show a column with the sum of periods.
152 142
153 --dsos:: 143 --dsos::
154 Only consider symbols in these dsos. 144 Only consider symbols in these dsos. This option will affect the
155 percentage of the overhead column. Se 145 percentage of the overhead column. See --percentage for more info.
156 146
157 --comms:: 147 --comms::
158 Only consider symbols in these comms. 148 Only consider symbols in these comms. This option will affect the
159 percentage of the overhead column. Se 149 percentage of the overhead column. See --percentage for more info.
160 150
161 --symbols:: 151 --symbols::
162 Only consider these symbols. This opt 152 Only consider these symbols. This option will affect the
163 percentage of the overhead column. Se 153 percentage of the overhead column. See --percentage for more info.
164 154
165 -M:: 155 -M::
166 --disassembler-style=:: Set disassembler style 156 --disassembler-style=:: Set disassembler style for objdump.
167 157
168 --addr2line=<path>:: <<
169 Path to addr2line binary. <<
170 <<
171 --objdump=<path>:: <<
172 Path to objdump binary. <<
173 <<
174 --prefix=PREFIX:: <<
175 --prefix-strip=N:: <<
176 Remove first N entries from source fil <<
177 and add PREFIX. This allows to display <<
178 with different file system layout. <<
179 <<
180 --source:: 158 --source::
181 Interleave source code with assembly c 159 Interleave source code with assembly code. Enabled by default,
182 disable with --no-source. 160 disable with --no-source.
183 161
184 --asm-raw:: 162 --asm-raw::
185 Show raw instruction encoding of assem 163 Show raw instruction encoding of assembly instructions.
186 164
187 -g:: 165 -g::
188 Enables call-graph (stack chain/backtr 166 Enables call-graph (stack chain/backtrace) recording.
189 167
190 --call-graph [mode,type,min[,limit],order[,key 168 --call-graph [mode,type,min[,limit],order[,key][,branch]]::
191 Setup and enable call-graph (stack cha 169 Setup and enable call-graph (stack chain/backtrace) recording,
192 implies -g. See `--call-graph` sectio 170 implies -g. See `--call-graph` section in perf-record and
193 perf-report man pages for details. 171 perf-report man pages for details.
194 172
195 --children:: 173 --children::
196 Accumulate callchain of children to pa 174 Accumulate callchain of children to parent entry so that then can
197 show up in the output. The output wil 175 show up in the output. The output will have a new "Children" column
198 and will be sorted on the data. It re 176 and will be sorted on the data. It requires -g/--call-graph option
199 enabled. See the `overhead calculatio 177 enabled. See the `overhead calculation' section for more details.
200 Enabled by default, disable with --no- 178 Enabled by default, disable with --no-children.
201 179
202 --max-stack:: 180 --max-stack::
203 Set the stack depth limit when parsing 181 Set the stack depth limit when parsing the callchain, anything
204 beyond the specified depth will be ign 182 beyond the specified depth will be ignored. This is a trade-off
205 between information loss and faster pr 183 between information loss and faster processing especially for
206 workloads that can have a very long ca 184 workloads that can have a very long callchain stack.
207 185
208 Default: /proc/sys/kernel/perf_event_m 186 Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise.
209 187
210 --ignore-callees=<regex>:: 188 --ignore-callees=<regex>::
211 Ignore callees of the function(s) matc 189 Ignore callees of the function(s) matching the given regex.
212 This has the effect of collecting the 190 This has the effect of collecting the callers of each such
213 function into one place in the call-gr 191 function into one place in the call-graph tree.
214 192
215 --percent-limit:: 193 --percent-limit::
216 Do not show entries which have an over 194 Do not show entries which have an overhead under that percent.
217 (Default: 0). 195 (Default: 0).
218 196
219 --percentage:: 197 --percentage::
220 Determine how to display the overhead 198 Determine how to display the overhead percentage of filtered entries.
221 Filters can be applied by --comms, --d 199 Filters can be applied by --comms, --dsos and/or --symbols options and
222 Zoom operations on the TUI (thread, ds 200 Zoom operations on the TUI (thread, dso, etc).
223 201
224 "relative" means it's relative to filt 202 "relative" means it's relative to filtered entries only so that the
225 sum of shown entries will be always 10 203 sum of shown entries will be always 100%. "absolute" means it retains
226 the original value before and after th 204 the original value before and after the filter is applied.
227 205
228 -w:: 206 -w::
229 --column-widths=<width[,width...]>:: 207 --column-widths=<width[,width...]>::
230 Force each column width to the provide 208 Force each column width to the provided list, for large terminal
231 readability. 0 means no limit (defaul 209 readability. 0 means no limit (default behavior).
232 210
233 --proc-map-timeout:: 211 --proc-map-timeout::
234 When processing pre-existing threads / 212 When processing pre-existing threads /proc/XXX/mmap, it may take
235 a long time, because the file may be h 213 a long time, because the file may be huge. A time out is needed
236 in such cases. 214 in such cases.
237 This option sets the time out limit. T 215 This option sets the time out limit. The default value is 500 ms.
238 216
239 217
240 -b:: 218 -b::
241 --branch-any:: 219 --branch-any::
242 Enable taken branch stack sampling. An 220 Enable taken branch stack sampling. Any type of taken branch may be sampled.
243 This is a shortcut for --branch-filter 221 This is a shortcut for --branch-filter any. See --branch-filter for more infos.
244 222
245 -j:: 223 -j::
246 --branch-filter:: 224 --branch-filter::
247 Enable taken branch stack sampling. Ea 225 Enable taken branch stack sampling. Each sample captures a series of consecutive
248 taken branches. The number of branches 226 taken branches. The number of branches captured with each sample depends on the
249 underlying hardware, the type of branc 227 underlying hardware, the type of branches of interest, and the executed code.
250 It is possible to select the types of 228 It is possible to select the types of branches captured by enabling filters.
251 For a full list of modifiers please se 229 For a full list of modifiers please see the perf record manpage.
252 230
253 The option requires at least one branc 231 The option requires at least one branch type among any, any_call, any_ret, ind_call, cond.
254 The privilege levels may be omitted, i 232 The privilege levels may be omitted, in which case, the privilege levels of the associated
255 event are applied to the branch filter 233 event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege
256 levels are subject to permissions. Wh 234 levels are subject to permissions. When sampling on multiple events, branch stack sampling
257 is enabled for all the sampling events 235 is enabled for all the sampling events. The sampled branch type is the same for all events.
258 The various filters must be specified 236 The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k
259 Note that this feature may not be avai 237 Note that this feature may not be available on all processors.
260 238
261 --branch-history:: <<
262 Add the addresses of sampled taken bra <<
263 This allows to examine the path the pr <<
264 <<
265 --raw-trace:: 239 --raw-trace::
266 When displaying traceevent output, do 240 When displaying traceevent output, do not use print fmt or plugins.
267 241
268 -H:: <<
269 --hierarchy:: 242 --hierarchy::
270 Enable hierarchical output. In the hi !! 243 Enable hierarchy output.
271 samples based on the criteria and then <<
272 level sort key. <<
273 <<
274 For example, in normal output: <<
275 <<
276 perf report -s dso,sym <<
277 # <<
278 # Overhead Shared Object Symbo <<
279 # ........ ................. ..... <<
280 50.00% [kernel.kallsyms] [k] k <<
281 20.00% perf [.] f <<
282 15.00% [kernel.kallsyms] [k] k <<
283 10.00% perf [.] b <<
284 5.00% libc.so [.] l <<
285 <<
286 In hierarchy output: <<
287 <<
288 perf report -s dso,sym --hierarchy <<
289 # <<
290 # Overhead Shared Object / Symbol <<
291 # .......... ...................... <<
292 65.00% [kernel.kallsyms] <<
293 50.00% [k] kfunc1 <<
294 15.00% [k] kfunc2 <<
295 30.00% perf <<
296 20.00% [.] foo <<
297 10.00% [.] bar <<
298 5.00% libc.so <<
299 5.00% [.] libcall <<
300 244
301 --overwrite:: 245 --overwrite::
302 Enable this to use just the most recen 246 Enable this to use just the most recent records, which helps in high core count
303 machines such as Knights Landing/Mill, 247 machines such as Knights Landing/Mill, but right now is disabled by default as
304 the pausing used in this technique is 248 the pausing used in this technique is leading to loss of metadata events such
305 as PERF_RECORD_MMAP which makes 'perf 249 as PERF_RECORD_MMAP which makes 'perf top' unable to resolve samples, leading
306 to lots of unknown samples appearing o 250 to lots of unknown samples appearing on the UI. Enable this if you are in such
307 machines and profiling a workload that 251 machines and profiling a workload that doesn't creates short lived threads and/or
308 doesn't uses many executable mmap oper 252 doesn't uses many executable mmap operations. Work is being planed to solve
309 this situation, till then, this will r 253 this situation, till then, this will remain disabled by default.
310 254
311 --force:: 255 --force::
312 Don't do ownership validation. 256 Don't do ownership validation.
313 257
314 --num-thread-synthesize:: 258 --num-thread-synthesize::
315 The number of threads to run when synt 259 The number of threads to run when synthesizing events for existing processes.
316 By default, the number of threads equa 260 By default, the number of threads equals to the number of online CPUs.
317 <<
318 --namespaces:: <<
319 Record events of type PERF_RECORD_NAME <<
320 'cgroup_id' sort key. <<
321 <<
322 -G name:: <<
323 --cgroup name:: <<
324 monitor only in the container (cgroup) called <<
325 in per-cpu mode. The cgroup filesystem must be <<
326 container "name" are monitored when they run o <<
327 can be provided. Each cgroup is applied to the <<
328 to first event, second cgroup to second event <<
329 an empty cgroup (monitor all the time) using, <<
330 corresponding events, i.e., they always refer <<
331 line. If the user wants to track multiple even <<
332 use '-e e1 -e e2 -G foo,foo' or just use '-e e <<
333 <<
334 --all-cgroups:: <<
335 Record events of type PERF_RECORD_CGRO <<
336 'cgroup' sort key. <<
337 <<
338 --switch-on EVENT_NAME:: <<
339 Only consider events after this event <<
340 <<
341 E.g.: <<
342 <<
343 Find out where broadcast packets ar <<
344 <<
345 perf probe -L icmp_rcv <<
346 <<
347 Insert a probe there: <<
348 <<
349 perf probe icmp_rcv:59 <<
350 <<
351 Start perf top and ask it to only c <<
352 broadcast packet arrives This will <<
353 will start counting when a broadcas <<
354 <<
355 perf top -e cycles,probe:icmp_ <<
356 <<
357 Alternatively one can ask for a gro <<
358 will appear, the first for cycles a <<
359 <<
360 perf top -e '{cycles,probe:icm <<
361 <<
362 This may be interesting to measure a w <<
363 phase is over, i.e. insert a perf prob <<
364 examples replacing probe:icmp_rcv with <<
365 <<
366 --switch-off EVENT_NAME:: <<
367 Stop considering events after this eve <<
368 <<
369 --show-on-off-events:: <<
370 Show the --switch-on/off events too. T <<
371 but probably we'll make the default no <<
372 on the --group mode and if there is on <<
373 go straight to the histogram browser, <<
374 explicitly specified does. <<
375 <<
376 --stitch-lbr:: <<
377 Show callgraph with stitched LBRs, whi <<
378 callgraph. The option must be used wit <<
379 Disabled by default. In common cases w <<
380 it can recreate better call stacks tha <<
381 output. But this approach is not foolp <<
382 where it creates incorrect call stacks <<
383 The known limitations include exceptio <<
384 setjmp/longjmp will have calls/returns <<
385 <<
386 ifdef::HAVE_LIBPFM[] <<
387 --pfm-events events:: <<
388 Select a PMU event using libpfm4 syntax (see h <<
389 including support for event filters. For examp <<
390 inst_retired:any_p:u:c=1:i'. More than one eve <<
391 option using the comma separator. Hardware eve <<
392 events cannot be mixed together. The latter mu <<
393 option. The -e option and this one can be mixe <<
394 can be grouped using the {} notation. <<
395 endif::HAVE_LIBPFM[] <<
396 261
397 INTERACTIVE PROMPTING KEYS 262 INTERACTIVE PROMPTING KEYS
398 -------------------------- 263 --------------------------
399 264
400 [d]:: 265 [d]::
401 Display refresh delay. 266 Display refresh delay.
402 267
403 [e]:: 268 [e]::
404 Number of entries to display. 269 Number of entries to display.
405 270
406 [E]:: 271 [E]::
407 Event to display when multiple counter 272 Event to display when multiple counters are active.
408 273
409 [f]:: 274 [f]::
410 Profile display filter (>= hit count). 275 Profile display filter (>= hit count).
411 276
412 [F]:: 277 [F]::
413 Annotation display filter (>= % of tot 278 Annotation display filter (>= % of total).
414 279
415 [s]:: 280 [s]::
416 Annotate symbol. 281 Annotate symbol.
417 282
418 [S]:: 283 [S]::
419 Stop annotation, return to full profil 284 Stop annotation, return to full profile display.
420 285
421 [K]:: 286 [K]::
422 Hide kernel symbols. 287 Hide kernel symbols.
423 288
424 [U]:: 289 [U]::
425 Hide user symbols. 290 Hide user symbols.
426 291
427 [z]:: 292 [z]::
428 Toggle event count zeroing across disp 293 Toggle event count zeroing across display updates.
429 294
430 [qQ]:: 295 [qQ]::
431 Quit. 296 Quit.
432 297
433 Pressing any unmapped key displays a menu, and 298 Pressing any unmapped key displays a menu, and prompts for input.
434 299
435 include::callchain-overhead-calculation.txt[] 300 include::callchain-overhead-calculation.txt[]
436 301
437 SEE ALSO 302 SEE ALSO
438 -------- 303 --------
439 linkperf:perf-stat[1], linkperf:perf-list[1], 304 linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1]
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