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.
66 allowed frequency, i.e. the value in t <<
67 sysctl. <<
68 59
69 -i:: 60 -i::
70 --inherit:: 61 --inherit::
71 Child tasks do not inherit counters. 62 Child tasks do not inherit counters.
72 63
73 -k <path>:: 64 -k <path>::
74 --vmlinux=<path>:: 65 --vmlinux=<path>::
75 Path to vmlinux. Required for annotat 66 Path to vmlinux. Required for annotation functionality.
76 67
77 --ignore-vmlinux:: <<
78 Ignore vmlinux files. <<
79 <<
80 --kallsyms=<file>:: <<
81 kallsyms pathname <<
82 <<
83 -m <pages>:: 68 -m <pages>::
84 --mmap-pages=<pages>:: 69 --mmap-pages=<pages>::
85 Number of mmap data pages (must be a p 70 Number of mmap data pages (must be a power of two) or size
86 specification in bytes with appended u !! 71 specification with appended unit character - B/K/M/G. The
87 The size is rounded up to the nearest !! 72 size is rounded up to have nearest pages power of two value.
88 73
89 -p <pid>:: 74 -p <pid>::
90 --pid=<pid>:: 75 --pid=<pid>::
91 Profile events on existing Process ID 76 Profile events on existing Process ID (comma separated list).
92 77
93 -t <tid>:: 78 -t <tid>::
94 --tid=<tid>:: 79 --tid=<tid>::
95 Profile events on existing thread ID ( 80 Profile events on existing thread ID (comma separated list).
96 81
97 -u:: 82 -u::
98 --uid=:: 83 --uid=::
99 Record events in threads owned by uid. 84 Record events in threads owned by uid. Name or number.
100 85
101 -r <priority>:: 86 -r <priority>::
102 --realtime=<priority>:: 87 --realtime=<priority>::
103 Collect data with this RT SCHED_FIFO p 88 Collect data with this RT SCHED_FIFO priority.
104 89
105 --sym-annotate=<symbol>:: 90 --sym-annotate=<symbol>::
106 Annotate this symbol. 91 Annotate this symbol.
107 92
108 -K:: 93 -K::
109 --hide_kernel_symbols:: 94 --hide_kernel_symbols::
110 Hide kernel symbols. 95 Hide kernel symbols.
111 96
112 -U:: 97 -U::
113 --hide_user_symbols:: 98 --hide_user_symbols::
114 Hide user symbols. 99 Hide user symbols.
115 100
116 --demangle-kernel:: 101 --demangle-kernel::
117 Demangle kernel symbols. 102 Demangle kernel symbols.
118 103
119 -D:: 104 -D::
120 --dump-symtab:: 105 --dump-symtab::
121 Dump the symbol table used for profili 106 Dump the symbol table used for profiling.
122 107
123 -v:: 108 -v::
124 --verbose:: 109 --verbose::
125 Be more verbose (show counter open err 110 Be more verbose (show counter open errors, etc).
126 111
127 -z:: 112 -z::
128 --zero:: 113 --zero::
129 Zero history across display updates. 114 Zero history across display updates.
130 115
131 -s:: 116 -s::
132 --sort:: 117 --sort::
133 Sort by key(s): pid, comm, dso, symbol 118 Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight,
134 local_weight, abort, in_tx, transactio 119 local_weight, abort, in_tx, transaction, overhead, sample, period.
135 Please see description of --sort in th 120 Please see description of --sort in the perf-report man page.
136 121
137 --fields=:: 122 --fields=::
138 Specify output field - multiple keys c 123 Specify output field - multiple keys can be specified in CSV format.
139 Following fields are available: 124 Following fields are available:
140 overhead, overhead_sys, overhead_us, o 125 overhead, overhead_sys, overhead_us, overhead_children, sample and period.
141 Also it can contain any sort key(s). 126 Also it can contain any sort key(s).
142 127
143 By default, every sort keys not specif 128 By default, every sort keys not specified in --field will be appended
144 automatically. 129 automatically.
145 130
146 -n:: 131 -n::
147 --show-nr-samples:: 132 --show-nr-samples::
148 Show a column with the number of sampl 133 Show a column with the number of samples.
149 134
150 --show-total-period:: 135 --show-total-period::
151 Show a column with the sum of periods. 136 Show a column with the sum of periods.
152 137
153 --dsos:: 138 --dsos::
154 Only consider symbols in these dsos. 139 Only consider symbols in these dsos. This option will affect the
155 percentage of the overhead column. Se 140 percentage of the overhead column. See --percentage for more info.
156 141
157 --comms:: 142 --comms::
158 Only consider symbols in these comms. 143 Only consider symbols in these comms. This option will affect the
159 percentage of the overhead column. Se 144 percentage of the overhead column. See --percentage for more info.
160 145
161 --symbols:: 146 --symbols::
162 Only consider these symbols. This opt 147 Only consider these symbols. This option will affect the
163 percentage of the overhead column. Se 148 percentage of the overhead column. See --percentage for more info.
164 149
165 -M:: 150 -M::
166 --disassembler-style=:: Set disassembler style 151 --disassembler-style=:: Set disassembler style for objdump.
167 152
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:: 153 --source::
181 Interleave source code with assembly c 154 Interleave source code with assembly code. Enabled by default,
182 disable with --no-source. 155 disable with --no-source.
183 156
184 --asm-raw:: 157 --asm-raw::
185 Show raw instruction encoding of assem 158 Show raw instruction encoding of assembly instructions.
186 159
187 -g:: 160 -g::
188 Enables call-graph (stack chain/backtr 161 Enables call-graph (stack chain/backtrace) recording.
189 162
190 --call-graph [mode,type,min[,limit],order[,key 163 --call-graph [mode,type,min[,limit],order[,key][,branch]]::
191 Setup and enable call-graph (stack cha 164 Setup and enable call-graph (stack chain/backtrace) recording,
192 implies -g. See `--call-graph` sectio 165 implies -g. See `--call-graph` section in perf-record and
193 perf-report man pages for details. 166 perf-report man pages for details.
194 167
195 --children:: 168 --children::
196 Accumulate callchain of children to pa 169 Accumulate callchain of children to parent entry so that then can
197 show up in the output. The output wil 170 show up in the output. The output will have a new "Children" column
198 and will be sorted on the data. It re 171 and will be sorted on the data. It requires -g/--call-graph option
199 enabled. See the `overhead calculatio 172 enabled. See the `overhead calculation' section for more details.
200 Enabled by default, disable with --no- <<
201 173
202 --max-stack:: 174 --max-stack::
203 Set the stack depth limit when parsing 175 Set the stack depth limit when parsing the callchain, anything
204 beyond the specified depth will be ign 176 beyond the specified depth will be ignored. This is a trade-off
205 between information loss and faster pr 177 between information loss and faster processing especially for
206 workloads that can have a very long ca 178 workloads that can have a very long callchain stack.
207 179
208 Default: /proc/sys/kernel/perf_event_m !! 180 Default: 127
209 181
210 --ignore-callees=<regex>:: 182 --ignore-callees=<regex>::
211 Ignore callees of the function(s) matc 183 Ignore callees of the function(s) matching the given regex.
212 This has the effect of collecting the 184 This has the effect of collecting the callers of each such
213 function into one place in the call-gr 185 function into one place in the call-graph tree.
214 186
215 --percent-limit:: 187 --percent-limit::
216 Do not show entries which have an over 188 Do not show entries which have an overhead under that percent.
217 (Default: 0). 189 (Default: 0).
218 190
219 --percentage:: 191 --percentage::
220 Determine how to display the overhead 192 Determine how to display the overhead percentage of filtered entries.
221 Filters can be applied by --comms, --d 193 Filters can be applied by --comms, --dsos and/or --symbols options and
222 Zoom operations on the TUI (thread, ds 194 Zoom operations on the TUI (thread, dso, etc).
223 195
224 "relative" means it's relative to filt 196 "relative" means it's relative to filtered entries only so that the
225 sum of shown entries will be always 10 197 sum of shown entries will be always 100%. "absolute" means it retains
226 the original value before and after th 198 the original value before and after the filter is applied.
227 199
228 -w:: 200 -w::
229 --column-widths=<width[,width...]>:: 201 --column-widths=<width[,width...]>::
230 Force each column width to the provide 202 Force each column width to the provided list, for large terminal
231 readability. 0 means no limit (defaul 203 readability. 0 means no limit (default behavior).
232 204
233 --proc-map-timeout:: 205 --proc-map-timeout::
234 When processing pre-existing threads / 206 When processing pre-existing threads /proc/XXX/mmap, it may take
235 a long time, because the file may be h 207 a long time, because the file may be huge. A time out is needed
236 in such cases. 208 in such cases.
237 This option sets the time out limit. T 209 This option sets the time out limit. The default value is 500 ms.
238 210
239 211
240 -b:: 212 -b::
241 --branch-any:: 213 --branch-any::
242 Enable taken branch stack sampling. An 214 Enable taken branch stack sampling. Any type of taken branch may be sampled.
243 This is a shortcut for --branch-filter 215 This is a shortcut for --branch-filter any. See --branch-filter for more infos.
244 216
245 -j:: 217 -j::
246 --branch-filter:: 218 --branch-filter::
247 Enable taken branch stack sampling. Ea 219 Enable taken branch stack sampling. Each sample captures a series of consecutive
248 taken branches. The number of branches 220 taken branches. The number of branches captured with each sample depends on the
249 underlying hardware, the type of branc 221 underlying hardware, the type of branches of interest, and the executed code.
250 It is possible to select the types of 222 It is possible to select the types of branches captured by enabling filters.
251 For a full list of modifiers please se 223 For a full list of modifiers please see the perf record manpage.
252 224
253 The option requires at least one branc 225 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 226 The privilege levels may be omitted, in which case, the privilege levels of the associated
255 event are applied to the branch filter 227 event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege
256 levels are subject to permissions. Wh 228 levels are subject to permissions. When sampling on multiple events, branch stack sampling
257 is enabled for all the sampling events 229 is enabled for all the sampling events. The sampled branch type is the same for all events.
258 The various filters must be specified 230 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 231 Note that this feature may not be available on all processors.
260 232
261 --branch-history:: <<
262 Add the addresses of sampled taken bra <<
263 This allows to examine the path the pr <<
264 <<
265 --raw-trace:: <<
266 When displaying traceevent output, do <<
267 <<
268 -H:: <<
269 --hierarchy:: <<
270 Enable hierarchical output. In the hi <<
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 <<
301 --overwrite:: <<
302 Enable this to use just the most recen <<
303 machines such as Knights Landing/Mill, <<
304 the pausing used in this technique is <<
305 as PERF_RECORD_MMAP which makes 'perf <<
306 to lots of unknown samples appearing o <<
307 machines and profiling a workload that <<
308 doesn't uses many executable mmap oper <<
309 this situation, till then, this will r <<
310 <<
311 --force:: <<
312 Don't do ownership validation. <<
313 <<
314 --num-thread-synthesize:: <<
315 The number of threads to run when synt <<
316 By default, the number of threads equa <<
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 <<
397 INTERACTIVE PROMPTING KEYS 233 INTERACTIVE PROMPTING KEYS
398 -------------------------- 234 --------------------------
399 235
400 [d]:: 236 [d]::
401 Display refresh delay. 237 Display refresh delay.
402 238
403 [e]:: 239 [e]::
404 Number of entries to display. 240 Number of entries to display.
405 241
406 [E]:: 242 [E]::
407 Event to display when multiple counter 243 Event to display when multiple counters are active.
408 244
409 [f]:: 245 [f]::
410 Profile display filter (>= hit count). 246 Profile display filter (>= hit count).
411 247
412 [F]:: 248 [F]::
413 Annotation display filter (>= % of tot 249 Annotation display filter (>= % of total).
414 250
415 [s]:: 251 [s]::
416 Annotate symbol. 252 Annotate symbol.
417 253
418 [S]:: 254 [S]::
419 Stop annotation, return to full profil 255 Stop annotation, return to full profile display.
420 <<
421 [K]:: <<
422 Hide kernel symbols. <<
423 <<
424 [U]:: <<
425 Hide user symbols. <<
426 256
427 [z]:: 257 [z]::
428 Toggle event count zeroing across disp 258 Toggle event count zeroing across display updates.
429 259
430 [qQ]:: 260 [qQ]::
431 Quit. 261 Quit.
432 262
433 Pressing any unmapped key displays a menu, and 263 Pressing any unmapped key displays a menu, and prompts for input.
434 264
435 include::callchain-overhead-calculation.txt[] 265 include::callchain-overhead-calculation.txt[]
436 266
437 SEE ALSO 267 SEE ALSO
438 -------- 268 --------
439 linkperf:perf-stat[1], linkperf:perf-list[1], 269 linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1]
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