1 perf-stat(1) 1 perf-stat(1)
2 ============ 2 ============
3 3
4 NAME 4 NAME
5 ---- 5 ----
6 perf-stat - Run a command and gather performan 6 perf-stat - Run a command and gather performance counter statistics
7 7
8 SYNOPSIS 8 SYNOPSIS
9 -------- 9 --------
10 [verse] 10 [verse]
11 'perf stat' [-e <EVENT> | --event=EVENT] [-a] 11 'perf stat' [-e <EVENT> | --event=EVENT] [-a] <command>
12 'perf stat' [-e <EVENT> | --event=EVENT] [-a] !! 12 'perf stat' [-e <EVENT> | --event=EVENT] [-a] -- <command> [<options>]
13 'perf stat' [-e <EVENT> | --event=EVENT] [-a] !! 13 'perf stat' [-e <EVENT> | --event=EVENT] [-a] record [-o file] -- <command> [<options>]
14 'perf stat' report [-i file] 14 'perf stat' report [-i file]
15 15
16 DESCRIPTION 16 DESCRIPTION
17 ----------- 17 -----------
18 This command runs a command and gathers perfor 18 This command runs a command and gathers performance counter statistics
19 from it. 19 from it.
20 20
21 21
22 OPTIONS 22 OPTIONS
23 ------- 23 -------
24 <command>...:: 24 <command>...::
25 Any command you can specify in a shell 25 Any command you can specify in a shell.
26 26
27 record:: 27 record::
28 See STAT RECORD. 28 See STAT RECORD.
29 29
30 report:: 30 report::
31 See STAT REPORT. 31 See STAT REPORT.
32 32
33 -e:: 33 -e::
34 --event=:: 34 --event=::
35 Select the PMU event. Selection can be 35 Select the PMU event. Selection can be:
36 36
37 - a symbolic event name (use 'perf lis 37 - a symbolic event name (use 'perf list' to list all events)
38 38
39 - a raw PMU event in the form of rN wh !! 39 - a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
40 that represents the raw register enc !! 40 hexadecimal event descriptor.
41 event control registers as described <<
42 /sys/bus/event_source/devices/cpu/fo <<
43 <<
44 - a symbolic or raw PMU event followed <<
45 and a list of event modifiers, e.g., <<
46 linkperf:perf-list[1] man page for d <<
47 41
48 - a symbolically formed event like 'pm 42 - a symbolically formed event like 'pmu/param1=0x3,param2/' where
49 param1 and param2 are defined as for 43 param1 and param2 are defined as formats for the PMU in
50 /sys/bus/event_source/devices/<pmu>/ 44 /sys/bus/event_source/devices/<pmu>/format/*
51 45
52 'percore' is a event qualifier that <<
53 hardware threads in a core. For exam <<
54 perf stat -A -a -e cpu/event,percore <<
55 <<
56 - a symbolically formed event like 'pm 46 - a symbolically formed event like 'pmu/config=M,config1=N,config2=K/'
57 where M, N, K are numbers (in decima 47 where M, N, K are numbers (in decimal, hex, octal format).
58 Acceptable values for each of 'confi 48 Acceptable values for each of 'config', 'config1' and 'config2'
59 parameters are defined by correspond 49 parameters are defined by corresponding entries in
60 /sys/bus/event_source/devices/<pmu>/ 50 /sys/bus/event_source/devices/<pmu>/format/*
61 51
62 Note that the last two syntaxes suppor <<
63 the PMU name to simplify creation of e <<
64 of the same type of PMU in large syste <<
65 Multiple PMU instances are typical for <<
66 'uncore_' is also ignored when perform <<
67 <<
68 <<
69 -i:: 52 -i::
70 --no-inherit:: 53 --no-inherit::
71 child tasks do not inherit counters 54 child tasks do not inherit counters
72 -p:: 55 -p::
73 --pid=<pid>:: 56 --pid=<pid>::
74 stat events on existing process id (co 57 stat events on existing process id (comma separated list)
75 58
76 -t:: 59 -t::
77 --tid=<tid>:: 60 --tid=<tid>::
78 stat events on existing thread id (com 61 stat events on existing thread id (comma separated list)
79 62
80 -b:: <<
81 --bpf-prog:: <<
82 stat events on existing bpf program id <<
83 requiring root rights. bpftool-prog co <<
84 id all bpf programs in the system. For <<
85 <<
86 # bpftool prog | head -n 1 <<
87 17247: tracepoint name sys_enter tag 192d5 <<
88 <<
89 # perf stat -e cycles,instructions --bpf-pro <<
90 <<
91 Performance counter stats for 'BPF program( <<
92 <<
93 85,967 cycles <<
94 28,982 instructions <<
95 <<
96 1.102235068 seconds time elapsed <<
97 <<
98 --bpf-counters:: <<
99 Use BPF programs to aggregate readings <<
100 allows multiple perf-stat sessions tha <<
101 instructions, etc.) to share hardware <<
102 To use BPF programs on common events b <<
103 "perf config stat.bpf-counter-events=< <<
104 <<
105 --bpf-attr-map:: <<
106 With option "--bpf-counters", differen <<
107 information about shared BPF programs <<
108 Use "--bpf-attr-map" to specify the pa <<
109 The default path is /sys/fs/bpf/perf_a <<
110 <<
111 ifdef::HAVE_LIBPFM[] <<
112 --pfm-events events:: <<
113 Select a PMU event using libpfm4 syntax (see h <<
114 including support for event filters. For examp <<
115 inst_retired:any_p:u:c=1:i'. More than one eve <<
116 option using the comma separator. Hardware eve <<
117 events cannot be mixed together. The latter mu <<
118 option. The -e option and this one can be mixe <<
119 can be grouped using the {} notation. <<
120 endif::HAVE_LIBPFM[] <<
121 63
122 -a:: 64 -a::
123 --all-cpus:: 65 --all-cpus::
124 system-wide collection from all CPUs ( 66 system-wide collection from all CPUs (default if no target is specified)
125 67
126 --no-scale:: !! 68 -c::
127 Don't scale/normalize counter values !! 69 --scale::
>> 70 scale/normalize counter values
128 71
129 -d:: 72 -d::
130 --detailed:: 73 --detailed::
131 print more detailed statistics, can be 74 print more detailed statistics, can be specified up to 3 times
132 75
133 -d: detailed events, L1 an 76 -d: detailed events, L1 and LLC data cache
134 -d -d: more detailed events, dTLB 77 -d -d: more detailed events, dTLB and iTLB events
135 -d -d -d: very detailed events, addin 78 -d -d -d: very detailed events, adding prefetch events
136 79
137 -r:: 80 -r::
138 --repeat=<n>:: 81 --repeat=<n>::
139 repeat command and print average + std 82 repeat command and print average + stddev (max: 100). 0 means forever.
140 83
141 -B:: 84 -B::
142 --big-num:: 85 --big-num::
143 print large numbers with thousands' se !! 86 print large numbers with thousands' separators according to locale
144 Enabled by default. Use "--no-big-num" <<
145 Default setting can be changed with "p <<
146 87
147 -C:: 88 -C::
148 --cpu=:: 89 --cpu=::
149 Count only on the list of CPUs provided. Multi 90 Count only on the list of CPUs provided. Multiple CPUs can be provided as a
150 comma-separated list with no space: 0,1. Range 91 comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
151 In per-thread mode, this option is ignored. Th 92 In per-thread mode, this option is ignored. The -a option is still necessary
152 to activate system-wide monitoring. Default is 93 to activate system-wide monitoring. Default is to count on all CPUs.
153 94
154 -A:: 95 -A::
155 --no-aggr:: 96 --no-aggr::
156 Do not aggregate counts across all monitored C 97 Do not aggregate counts across all monitored CPUs.
157 98
158 -n:: 99 -n::
159 --null:: 100 --null::
160 null run - Don't start any counters. !! 101 null run - don't start any counters
161 <<
162 This can be useful to measure just elapsed wal <<
163 raw overhead of perf stat itself, without runn <<
164 102
165 -v:: 103 -v::
166 --verbose:: 104 --verbose::
167 be more verbose (show counter open err 105 be more verbose (show counter open errors, etc)
168 106
169 -x SEP:: 107 -x SEP::
170 --field-separator SEP:: 108 --field-separator SEP::
171 print counts using a CSV-style output to make 109 print counts using a CSV-style output to make it easy to import directly into
172 spreadsheets. Columns are separated by the str 110 spreadsheets. Columns are separated by the string specified in SEP.
173 111
174 --table:: Display time for each run (-r option <<
175 <<
176 $ perf stat --null -r 5 --table perf bench s <<
177 <<
178 Performance counter stats for 'perf bench s <<
179 <<
180 # Table of individual measurement <<
181 5.189 (-0.293) # <<
182 5.189 (-0.294) # <<
183 5.186 (-0.296) # <<
184 5.663 (+0.181) ## <<
185 6.186 (+0.703) #### <<
186 <<
187 # Final result: <<
188 5.483 +- 0.198 seconds time elaps <<
189 <<
190 -G name:: 112 -G name::
191 --cgroup name:: 113 --cgroup name::
192 monitor only in the container (cgroup) called 114 monitor only in the container (cgroup) called "name". This option is available only
193 in per-cpu mode. The cgroup filesystem must be 115 in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
194 container "name" are monitored when they run o 116 container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
195 can be provided. Each cgroup is applied to the 117 can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
196 to first event, second cgroup to second event 118 to first event, second cgroup to second event and so on. It is possible to provide
197 an empty cgroup (monitor all the time) using, 119 an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
198 corresponding events, i.e., they always refer 120 corresponding events, i.e., they always refer to events defined earlier on the command
199 line. If the user wants to track multiple even !! 121 line.
200 use '-e e1 -e e2 -G foo,foo' or just use '-e e <<
201 <<
202 If wanting to monitor, say, 'cycles' for a cgr <<
203 command line can be used: 'perf stat -e cycles <<
204 <<
205 --for-each-cgroup name:: <<
206 Expand event list for each cgroup in "name" (a <<
207 by comma). It also support regex patterns to <<
208 effect that repeating -e option and -G option <<
209 cannot be used with -G/--cgroup option. <<
210 122
211 -o file:: 123 -o file::
212 --output file:: 124 --output file::
213 Print the output into the designated file. 125 Print the output into the designated file.
214 126
215 --append:: 127 --append::
216 Append to the output file designated with the 128 Append to the output file designated with the -o option. Ignored if -o is not specified.
217 129
218 --log-fd:: 130 --log-fd::
219 131
220 Log output to fd, instead of stderr. Compleme 132 Log output to fd, instead of stderr. Complementary to --output, and mutually exclusive
221 with it. --append may be used here. Examples 133 with it. --append may be used here. Examples:
222 3>results perf stat --log-fd 3 !! 134 3>results perf stat --log-fd 3 -- $cmd
223 3>>results perf stat --log-fd 3 --append !! 135 3>>results perf stat --log-fd 3 --append -- $cmd
224 <<
225 --control=fifo:ctl-fifo[,ack-fifo]:: <<
226 --control=fd:ctl-fd[,ack-fd]:: <<
227 ctl-fifo / ack-fifo are opened and used as ctl <<
228 Listen on ctl-fd descriptor for command to con <<
229 'disable': disable events). Measurements can b <<
230 --delay=-1 option. Optionally send control com <<
231 to synchronize with the controlling process. E <<
232 disable events during measurements: <<
233 <<
234 #!/bin/bash <<
235 <<
236 ctl_dir=/tmp/ <<
237 <<
238 ctl_fifo=${ctl_dir}perf_ctl.fifo <<
239 test -p ${ctl_fifo} && unlink ${ctl_fifo} <<
240 mkfifo ${ctl_fifo} <<
241 exec {ctl_fd}<>${ctl_fifo} <<
242 <<
243 ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo <<
244 test -p ${ctl_ack_fifo} && unlink ${ctl_ack_f <<
245 mkfifo ${ctl_ack_fifo} <<
246 exec {ctl_fd_ack}<>${ctl_ack_fifo} <<
247 <<
248 perf stat -D -1 -e cpu-cycles -a -I 1000 <<
249 --control fd:${ctl_fd},${ctl_fd_ack <<
250 \-- sleep 30 & <<
251 perf_pid=$! <<
252 <<
253 sleep 5 && echo 'enable' >&${ctl_fd} && read <<
254 sleep 10 && echo 'disable' >&${ctl_fd} && rea <<
255 <<
256 exec {ctl_fd_ack}>&- <<
257 unlink ${ctl_ack_fifo} <<
258 <<
259 exec {ctl_fd}>&- <<
260 unlink ${ctl_fifo} <<
261 <<
262 wait -n ${perf_pid} <<
263 exit $? <<
264 <<
265 136
266 --pre:: 137 --pre::
267 --post:: 138 --post::
268 Pre and post measurement hooks, e.g.: 139 Pre and post measurement hooks, e.g.:
269 140
270 perf stat --repeat 10 --null --sync --pre 'mak !! 141 perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage
271 142
272 -I msecs:: 143 -I msecs::
273 --interval-print msecs:: 144 --interval-print msecs::
274 Print count deltas every N milliseconds (minim !! 145 Print count deltas every N milliseconds (minimum: 10ms)
275 The overhead percentage could be high in some 146 The overhead percentage could be high in some cases, for instance with small, sub 100ms intervals. Use with caution.
276 example: 'perf stat -I 1000 -e cycles 147 example: 'perf stat -I 1000 -e cycles -a sleep 5'
277 148
278 If the metric exists, it is calculated by the <<
279 <<
280 --interval-count times:: <<
281 Print count deltas for fixed number of times. <<
282 This option should be used together with "-I" <<
283 example: 'perf stat -I 1000 --interval <<
284 <<
285 --interval-clear:: <<
286 Clear the screen before next interval. <<
287 <<
288 --timeout msecs:: <<
289 Stop the 'perf stat' session and print count d <<
290 This option is not supported with the "-I" opt <<
291 example: 'perf stat --time 2000 -e cyc <<
292 <<
293 --metric-only:: 149 --metric-only::
294 Only print computed metrics. Print them in a s 150 Only print computed metrics. Print them in a single line.
295 Don't show any raw values. Not supported with 151 Don't show any raw values. Not supported with --per-thread.
296 152
297 --per-socket:: 153 --per-socket::
298 Aggregate counts per processor socket for syst 154 Aggregate counts per processor socket for system-wide mode measurements. This
299 is a useful mode to detect imbalance between s 155 is a useful mode to detect imbalance between sockets. To enable this mode,
300 use --per-socket in addition to -a. (system-wi 156 use --per-socket in addition to -a. (system-wide). The output includes the
301 socket number and the number of online process 157 socket number and the number of online processors on that socket. This is
302 useful to gauge the amount of aggregation. 158 useful to gauge the amount of aggregation.
303 159
304 --per-die:: <<
305 Aggregate counts per processor die for system- <<
306 is a useful mode to detect imbalance between d <<
307 use --per-die in addition to -a. (system-wide) <<
308 die number and the number of online processors <<
309 useful to gauge the amount of aggregation. <<
310 <<
311 --per-cluster:: <<
312 Aggregate counts per processor cluster for sys <<
313 is a useful mode to detect imbalance between c <<
314 use --per-cluster in addition to -a. (system-w <<
315 cluster number and the number of online proces <<
316 useful to gauge the amount of aggregation. The <<
317 related CPUs can be gotten from /sys/devices/s <<
318 <<
319 --per-cache:: <<
320 Aggregate counts per cache instance for system <<
321 default, the aggregation happens for the cache <<
322 in the system. To specify a particular level, <<
323 alongside the option in the format [Ll][1-9][0 <<
324 Using option "--per-cache=l3" or "--per-cache= <<
325 information at the boundary of the level 3 cac <<
326 <<
327 --per-core:: 160 --per-core::
328 Aggregate counts per physical processor for sy 161 Aggregate counts per physical processor for system-wide mode measurements. This
329 is a useful mode to detect imbalance between p 162 is a useful mode to detect imbalance between physical cores. To enable this mode,
330 use --per-core in addition to -a. (system-wide 163 use --per-core in addition to -a. (system-wide). The output includes the
331 core number and the number of online logical p 164 core number and the number of online logical processors on that physical processor.
332 165
333 --per-thread:: 166 --per-thread::
334 Aggregate counts per monitored threads, when m 167 Aggregate counts per monitored threads, when monitoring threads (-t option)
335 or processes (-p option). 168 or processes (-p option).
336 169
337 --per-node:: <<
338 Aggregate counts per NUMA nodes for system-wid <<
339 is a useful mode to detect imbalance between N <<
340 mode, use --per-node in addition to -a. (syste <<
341 <<
342 -D msecs:: 170 -D msecs::
343 --delay msecs:: 171 --delay msecs::
344 After starting the program, wait msecs before !! 172 After starting the program, wait msecs before measuring. This is useful to
345 disabled). This is useful to filter out the st !! 173 filter out the startup phase of the program, which is often very different.
346 which is often very different. <<
347 174
348 -T:: 175 -T::
349 --transaction:: 176 --transaction::
350 177
351 Print statistics of transactional execution if 178 Print statistics of transactional execution if supported.
352 179
353 --metric-no-group:: <<
354 By default, events to compute a metric are pla <<
355 group tries to enforce scheduling all or none <<
356 --metric-no-group option places events outside <<
357 increase the chance of the event being schedul <<
358 accuracy. However, as events may not be schedu <<
359 for metrics like instructions per cycle can be <<
360 may no longer be being measured at the same ti <<
361 <<
362 --metric-no-merge:: <<
363 By default metric events in different weak gro <<
364 group contains all the events needed by anothe <<
365 group will be eliminated reducing event multip <<
366 that certain groups of metrics sum to 100%. A <<
367 group is that the group may require multiplexi <<
368 small group that need not have multiplexing is <<
369 forbids the event merging logic from sharing e <<
370 may be used to increase accuracy in this case. <<
371 <<
372 --metric-no-threshold:: <<
373 Metric thresholds may increase the number of e <<
374 compute whether a metric has exceeded its thre <<
375 may not be desirable, for example, as the even <<
376 multiplexing. This option disables the adding <<
377 events for a metric. However, if there are suf <<
378 compute the threshold then the threshold is st <<
379 color the metric's computed value. <<
380 <<
381 --quiet:: <<
382 Don't print output, warnings or messages. This <<
383 record below to only write data to the perf.da <<
384 <<
385 STAT RECORD 180 STAT RECORD
386 ----------- 181 -----------
387 Stores stat data into perf data file. 182 Stores stat data into perf data file.
388 183
389 -o file:: 184 -o file::
390 --output file:: 185 --output file::
391 Output file name. 186 Output file name.
392 187
393 STAT REPORT 188 STAT REPORT
394 ----------- 189 -----------
395 Reads and reports stat data from perf data fil 190 Reads and reports stat data from perf data file.
396 191
397 -i file:: 192 -i file::
398 --input file:: 193 --input file::
399 Input file name. 194 Input file name.
400 195
401 --per-socket:: 196 --per-socket::
402 Aggregate counts per processor socket for syst 197 Aggregate counts per processor socket for system-wide mode measurements.
403 198
404 --per-die:: <<
405 Aggregate counts per processor die for system- <<
406 <<
407 --per-cluster:: <<
408 Aggregate counts perf processor cluster for sy <<
409 <<
410 --per-cache:: <<
411 Aggregate counts per cache instance for system <<
412 default, the aggregation happens for the cache <<
413 in the system. To specify a particular level, <<
414 alongside the option in the format [Ll][1-9][0 <<
415 option "--per-cache=l3" or "--per-cache=L3" wi <<
416 information at the boundary of the level 3 cac <<
417 <<
418 --per-core:: 199 --per-core::
419 Aggregate counts per physical processor for sy 200 Aggregate counts per physical processor for system-wide mode measurements.
420 201
421 -M:: 202 -M::
422 --metrics:: 203 --metrics::
423 Print metrics or metricgroups specified in a c 204 Print metrics or metricgroups specified in a comma separated list.
424 For a group all metrics from the group are add 205 For a group all metrics from the group are added.
425 The events from the metrics are automatically 206 The events from the metrics are automatically measured.
426 See perf list output for the possible metrics !! 207 See perf list output for the possble metrics and metricgroups.
427 <<
428 When threshold information is availabl <<
429 color red is used to signify a metric <<
430 while green shows it hasn't. The defau <<
431 no threshold information was available <<
432 couldn't be computed. <<
433 208
434 -A:: 209 -A::
435 --no-aggr:: 210 --no-aggr::
436 --no-merge:: !! 211 Do not aggregate counts across all monitored CPUs.
437 Do not aggregate/merge counts across monitored <<
438 <<
439 When multiple events are created from a single <<
440 stat will, by default, aggregate the event cou <<
441 in a single row. This option disables that beh <<
442 individual events and counts. <<
443 <<
444 Multiple events are created from a single even <<
445 <<
446 1. PID monitoring isn't requested and the syst <<
447 CPU. For example, a system with 8 SMT threa <<
448 opened on each thread and aggregation is pe <<
449 <<
450 2. Prefix or glob wildcard matching is used fo <<
451 example, multiple memory controller PMUs ma <<
452 suffix of _0, _1, etc. By default the event <<
453 combined if the PMU is specified without th <<
454 uncore_imc rather than uncore_imc_0. <<
455 <<
456 3. Aliases, which are listed immediately after <<
457 by perf list, are used. <<
458 <<
459 --hybrid-merge:: <<
460 Merge core event counts from all core PMUs. In <<
461 systems by default each core PMU will report i <<
462 separately. This option forces core PMU counts <<
463 a behavior closer to having a single CPU type <<
464 212
465 --topdown:: 213 --topdown::
466 Print top-down metrics supported by the CPU. T !! 214 Print top down level 1 metrics if supported by the CPU. This allows to
467 bottle necks in the CPU pipeline for CPU bound !! 215 determine bottle necks in the CPU pipeline for CPU bound workloads,
468 the cycles consumed down into frontend bound, !! 216 by breaking the cycles consumed down into frontend bound, backend bound,
469 speculation and retiring. !! 217 bad speculation and retiring.
470 218
471 Frontend bound means that the CPU cannot fetch 219 Frontend bound means that the CPU cannot fetch and decode instructions fast
472 enough. Backend bound means that computation o 220 enough. Backend bound means that computation or memory access is the bottle
473 neck. Bad Speculation means that the CPU waste 221 neck. Bad Speculation means that the CPU wasted cycles due to branch
474 mispredictions and similar issues. Retiring me 222 mispredictions and similar issues. Retiring means that the CPU computed without
475 an apparently bottleneck. The bottleneck is on 223 an apparently bottleneck. The bottleneck is only the real bottleneck
476 if the workload is actually bound by the CPU a 224 if the workload is actually bound by the CPU and not by something else.
477 225
478 For best results it is usually a good idea to 226 For best results it is usually a good idea to use it with interval
479 mode like -I 1000, as the bottleneck of worklo 227 mode like -I 1000, as the bottleneck of workloads can change often.
480 228
481 This enables --metric-only, unless overridden <<
482 <<
483 The following restrictions only apply to older <<
484 on newer CPUs (IceLake and later) TopDown can <<
485 <<
486 The top down metrics are collected per core in 229 The top down metrics are collected per core instead of per
487 CPU thread. Per core mode is automatically ena 230 CPU thread. Per core mode is automatically enabled
488 and -a (global monitoring) is needed, requirin 231 and -a (global monitoring) is needed, requiring root rights or
489 perf.perf_event_paranoid=-1. 232 perf.perf_event_paranoid=-1.
490 233
491 Topdown uses the full Performance Monitoring U 234 Topdown uses the full Performance Monitoring Unit, and needs
492 disabling of the NMI watchdog (as root): 235 disabling of the NMI watchdog (as root):
493 echo 0 > /proc/sys/kernel/nmi_watchdog 236 echo 0 > /proc/sys/kernel/nmi_watchdog
494 for best results. Otherwise the bottlenecks ma 237 for best results. Otherwise the bottlenecks may be inconsistent
495 on workload with changing phases. 238 on workload with changing phases.
496 239
>> 240 This enables --metric-only, unless overriden with --no-metric-only.
>> 241
497 To interpret the results it is usually needed 242 To interpret the results it is usually needed to know on which
498 CPUs the workload runs on. If needed the CPUs 243 CPUs the workload runs on. If needed the CPUs can be forced using
499 taskset. 244 taskset.
500 245
501 --record-tpebs:: !! 246 --no-merge::
502 Enable automatic sampling on Intel TPEBS retir !! 247 Do not merge results from same PMUs.
503 modifier). Without this option, perf would not <<
504 at runtime. Currently, a zero value is assigne <<
505 this option is not set. The TPEBS hardware fea <<
506 Rapids microarchitecture. This option only exi <<
507 Intel platforms with TPEBS feature. <<
508 <<
509 --td-level:: <<
510 Print the top-down statistics that equal the i <<
511 users to print the interested top-down metrics <<
512 level 1 top-down metrics. <<
513 <<
514 As the higher levels gather more metrics and u <<
515 will be less accurate. By convention a metric <<
516 appending '_group' to it and this will increas <<
517 gathering all metrics for a level. For example <<
518 highlight 'tma_frontend_bound'. This metric ma <<
519 'tma_frontend_bound_group' with <<
520 'perf stat -M tma_frontend_bound_group...'. <<
521 <<
522 Error out if the input is higher than the supp <<
523 248
524 --smi-cost:: 249 --smi-cost::
525 Measure SMI cost if msr/aperf/ and msr/smi/ ev 250 Measure SMI cost if msr/aperf/ and msr/smi/ events are supported.
526 251
527 During the measurement, the /sys/device/cpu/fr 252 During the measurement, the /sys/device/cpu/freeze_on_smi will be set to
528 freeze core counters on SMI. 253 freeze core counters on SMI.
529 The aperf counter will not be effected by the 254 The aperf counter will not be effected by the setting.
530 The cost of SMI can be measured by (aperf - un 255 The cost of SMI can be measured by (aperf - unhalted core cycles).
531 256
532 In practice, the percentages of SMI cycles is 257 In practice, the percentages of SMI cycles is very useful for performance
533 oriented analysis. --metric_only will be appli 258 oriented analysis. --metric_only will be applied by default.
534 The output is SMI cycles%, equals to (aperf - 259 The output is SMI cycles%, equals to (aperf - unhalted core cycles) / aperf
535 260
536 Users who wants to get the actual value can ap 261 Users who wants to get the actual value can apply --no-metric-only.
537 262
538 --all-kernel:: <<
539 Configure all used events to run in kernel spa <<
540 <<
541 --all-user:: <<
542 Configure all used events to run in user space <<
543 <<
544 --percore-show-thread:: <<
545 The event modifier "percore" has supported to <<
546 for all hardware threads in a core and show th <<
547 <<
548 This option with event modifier "percore" enab <<
549 counts for all hardware threads in a core but <<
550 hardware thread. This is essentially a replace <<
551 convenient for post processing. <<
552 <<
553 --summary:: <<
554 Print summary for interval mode (-I). <<
555 <<
556 --no-csv-summary:: <<
557 Don't print 'summary' at the first column for <<
558 This option must be used with -x and --summary <<
559 <<
560 This option can be enabled in perf config by s <<
561 'stat.no-csv-summary'. <<
562 <<
563 $ perf config stat.no-csv-summary=true <<
564 <<
565 --cputype:: <<
566 Only enable events on applying cpu with this t <<
567 (e.g. core or atom)" <<
568 <<
569 EXAMPLES 263 EXAMPLES
570 -------- 264 --------
571 265
572 $ perf stat \-- make !! 266 $ perf stat -- make -j
573 <<
574 Performance counter stats for 'make': <<
575 <<
576 83723.452481 task-clock:u (msec) <<
577 0 context-switches:u <<
578 0 cpu-migrations:u <<
579 3,228,188 page-faults:u <<
580 229,570,665,834 cycles:u <<
581 313,163,853,778 instructions:u <<
582 69,704,684,856 branches:u <<
583 2,078,861,393 branch-misses:u <<
584 <<
585 83.409183620 seconds time elapsed <<
586 <<
587 74.684747000 seconds user <<
588 8.739217000 seconds sys <<
589 <<
590 TIMINGS <<
591 ------- <<
592 As displayed in the example above we can displ <<
593 We always display the time the counters were e <<
594 <<
595 83.409183620 seconds time elapsed <<
596 267
597 For workload sessions we also display time the !! 268 Performance counter stats for 'make -j':
598 user/system lands: <<
599 269
600 74.684747000 seconds user !! 270 8117.370256 task clock ticks # 11.281 CPU utilization factor
601 8.739217000 seconds sys !! 271 678 context switches # 0.000 M/sec
>> 272 133 CPU migrations # 0.000 M/sec
>> 273 235724 pagefaults # 0.029 M/sec
>> 274 24821162526 CPU cycles # 3057.784 M/sec
>> 275 18687303457 instructions # 2302.138 M/sec
>> 276 172158895 cache references # 21.209 M/sec
>> 277 27075259 cache misses # 3.335 M/sec
602 278
603 Those times are the very same as displayed by !! 279 Wall-clock time elapsed: 719.554352 msecs
604 280
605 CSV FORMAT 281 CSV FORMAT
606 ---------- 282 ----------
607 283
608 With -x, perf stat is able to output a not-qui 284 With -x, perf stat is able to output a not-quite-CSV format output
609 Commas in the output are not put into "". To m 285 Commas in the output are not put into "". To make it easy to parse
610 it is recommended to use a different character 286 it is recommended to use a different character like -x \;
611 287
612 The fields are in this order: 288 The fields are in this order:
613 289
614 - optional usec time stamp in fraction 290 - optional usec time stamp in fractions of second (with -I xxx)
615 - optional CPU, core, or socket identi 291 - optional CPU, core, or socket identifier
616 - optional number of logical CPUs aggr 292 - optional number of logical CPUs aggregated
617 - counter value 293 - counter value
618 - unit of the counter value or empty 294 - unit of the counter value or empty
619 - event name 295 - event name
620 - run time of counter 296 - run time of counter
621 - percentage of measurement time the c 297 - percentage of measurement time the counter was running
622 - optional variance if multiple values 298 - optional variance if multiple values are collected with -r
623 - optional metric value 299 - optional metric value
624 - optional unit of metric 300 - optional unit of metric
625 301
626 Additional metrics may be printed with all ear 302 Additional metrics may be printed with all earlier fields being empty.
627 <<
628 include::intel-hybrid.txt[] <<
629 <<
630 JSON FORMAT <<
631 ----------- <<
632 <<
633 With -j, perf stat is able to print out a JSON <<
634 that can be used for parsing. <<
635 <<
636 - timestamp : optional usec time stamp in frac <<
637 - optional aggregate options: <<
638 - core : core identifier (with <<
639 - die : die identifier (with - <<
640 - socket : socket identifier ( <<
641 - node : node identifier (with <<
642 - thread : thread identifier ( <<
643 - counter-value : counter value <<
644 - unit : unit of the counter value or empty <<
645 - event : event name <<
646 - variance : optional variance if multiple val <<
647 - runtime : run time of counter <<
648 - metric-value : optional metric value <<
649 - metric-unit : optional unit of metric <<
650 303
651 SEE ALSO 304 SEE ALSO
652 -------- 305 --------
653 linkperf:perf-top[1], linkperf:perf-list[1] 306 linkperf:perf-top[1], linkperf:perf-list[1]
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