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 There are also some params which are not defined in .../<pmu>/format/*. 49 These params can be used to overload default config values per event. 50 Here is a list of the params. 51 - 'period': Set event sampling period 52 - 'freq': Set event sampling frequency 53 - 'time': Disable/enable time stamping. Acceptable values are 1 for 54 enabling time stamping. 0 for disabling time stamping. 55 The default is 1. 56 - 'call-graph': Disable/enable callgraph. Acceptable str are "fp" for 57 FP mode, "dwarf" for DWARF mode, "lbr" for LBR mode and 58 "no" for disable callgraph. 59 - 'stack-size': user stack size for dwarf mode 60 Note: If user explicitly sets options which conflict with the params, 61 the value set by the params will be overridden. 62 63 - a hardware breakpoint event in the form of '\mem:addr[/len][:access]' 64 where addr is the address in memory you want to break in. 65 Access is the memory access type (read, write, execute) it can 66 be passed as follows: '\mem:addr[:[r][w][x]]'. len is the range, 67 number of bytes from specified addr, which the breakpoint will cover. 68 If you want to profile read-write accesses in 0x1000, just set 69 'mem:0x1000:rw'. 70 If you want to profile write accesses in [0x1000~1008), just set 71 'mem:0x1000/8:w'. 72 73 - a group of events surrounded by a pair of brace ("{event1,event2,...}"). 74 Each event is separated by commas and the group should be quoted to 75 prevent the shell interpretation. You also need to use --group on 76 "perf report" to view group events together. 77 78--filter=<filter>:: 79 Event filter. This option should follow a event selector (-e) which 80 selects tracepoint event(s). Multiple '--filter' options are combined 81 using '&&'. 82 83--exclude-perf:: 84 Don't record events issued by perf itself. This option should follow 85 a event selector (-e) which selects tracepoint event(s). It adds a 86 filter expression 'common_pid != $PERFPID' to filters. If other 87 '--filter' exists, the new filter expression will be combined with 88 them by '&&'. 89 90-a:: 91--all-cpus:: 92 System-wide collection from all CPUs. 93 94-p:: 95--pid=:: 96 Record events on existing process ID (comma separated list). 97 98-t:: 99--tid=:: 100 Record events on existing thread ID (comma separated list). 101 This option also disables inheritance by default. Enable it by adding 102 --inherit. 103 104-u:: 105--uid=:: 106 Record events in threads owned by uid. Name or number. 107 108-r:: 109--realtime=:: 110 Collect data with this RT SCHED_FIFO priority. 111 112--no-buffering:: 113 Collect data without buffering. 114 115-c:: 116--count=:: 117 Event period to sample. 118 119-o:: 120--output=:: 121 Output file name. 122 123-i:: 124--no-inherit:: 125 Child tasks do not inherit counters. 126-F:: 127--freq=:: 128 Profile at this frequency. 129 130-m:: 131--mmap-pages=:: 132 Number of mmap data pages (must be a power of two) or size 133 specification with appended unit character - B/K/M/G. The 134 size is rounded up to have nearest pages power of two value. 135 Also, by adding a comma, the number of mmap pages for AUX 136 area tracing can be specified. 137 138--group:: 139 Put all events in a single event group. This precedes the --event 140 option and remains only for backward compatibility. See --event. 141 142-g:: 143 Enables call-graph (stack chain/backtrace) recording. 144 145--call-graph:: 146 Setup and enable call-graph (stack chain/backtrace) recording, 147 implies -g. Default is "fp". 148 149 Allows specifying "fp" (frame pointer) or "dwarf" 150 (DWARF's CFI - Call Frame Information) or "lbr" 151 (Hardware Last Branch Record facility) as the method to collect 152 the information used to show the call graphs. 153 154 In some systems, where binaries are build with gcc 155 --fomit-frame-pointer, using the "fp" method will produce bogus 156 call graphs, using "dwarf", if available (perf tools linked to 157 the libunwind or libdw library) should be used instead. 158 Using the "lbr" method doesn't require any compiler options. It 159 will produce call graphs from the hardware LBR registers. The 160 main limition is that it is only available on new Intel 161 platforms, such as Haswell. It can only get user call chain. It 162 doesn't work with branch stack sampling at the same time. 163 164 When "dwarf" recording is used, perf also records (user) stack dump 165 when sampled. Default size of the stack dump is 8192 (bytes). 166 User can change the size by passing the size after comma like 167 "--call-graph dwarf,4096". 168 169-q:: 170--quiet:: 171 Don't print any message, useful for scripting. 172 173-v:: 174--verbose:: 175 Be more verbose (show counter open errors, etc). 176 177-s:: 178--stat:: 179 Record per-thread event counts. Use it with 'perf report -T' to see 180 the values. 181 182-d:: 183--data:: 184 Record the sample addresses. 185 186-T:: 187--timestamp:: 188 Record the sample timestamps. Use it with 'perf report -D' to see the 189 timestamps, for instance. 190 191-P:: 192--period:: 193 Record the sample period. 194 195-n:: 196--no-samples:: 197 Don't sample. 198 199-R:: 200--raw-samples:: 201Collect raw sample records from all opened counters (default for tracepoint counters). 202 203-C:: 204--cpu:: 205Collect samples only on the list of CPUs provided. Multiple CPUs can be provided as a 206comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2. 207In per-thread mode with inheritance mode on (default), samples are captured only when 208the thread executes on the designated CPUs. Default is to monitor all CPUs. 209 210-B:: 211--no-buildid:: 212Do not save the build ids of binaries in the perf.data files. This skips 213post processing after recording, which sometimes makes the final step in 214the recording process to take a long time, as it needs to process all 215events looking for mmap records. The downside is that it can misresolve 216symbols if the workload binaries used when recording get locally rebuilt 217or upgraded, because the only key available in this case is the 218pathname. You can also set the "record.build-id" config variable to 219'skip to have this behaviour permanently. 220 221-N:: 222--no-buildid-cache:: 223Do not update the buildid cache. This saves some overhead in situations 224where the information in the perf.data file (which includes buildids) 225is sufficient. You can also set the "record.build-id" config variable to 226'no-cache' to have the same effect. 227 228-G name,...:: 229--cgroup name,...:: 230monitor only in the container (cgroup) called "name". This option is available only 231in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to 232container "name" are monitored when they run on the monitored CPUs. Multiple cgroups 233can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup 234to first event, second cgroup to second event and so on. It is possible to provide 235an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have 236corresponding events, i.e., they always refer to events defined earlier on the command 237line. 238 239-b:: 240--branch-any:: 241Enable taken branch stack sampling. Any type of taken branch may be sampled. 242This is a shortcut for --branch-filter any. See --branch-filter for more infos. 243 244-j:: 245--branch-filter:: 246Enable taken branch stack sampling. Each sample captures a series of consecutive 247taken branches. The number of branches captured with each sample depends on the 248underlying hardware, the type of branches of interest, and the executed code. 249It is possible to select the types of branches captured by enabling filters. The 250following filters are defined: 251 252 - any: any type of branches 253 - any_call: any function call or system call 254 - any_ret: any function return or system call return 255 - ind_call: any indirect branch 256 - call: direct calls, including far (to/from kernel) calls 257 - u: only when the branch target is at the user level 258 - k: only when the branch target is in the kernel 259 - hv: only when the target is at the hypervisor level 260 - in_tx: only when the target is in a hardware transaction 261 - no_tx: only when the target is not in a hardware transaction 262 - abort_tx: only when the target is a hardware transaction abort 263 - cond: conditional branches 264 265+ 266The option requires at least one branch type among any, any_call, any_ret, ind_call, cond. 267The privilege levels may be omitted, in which case, the privilege levels of the associated 268event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege 269levels are subject to permissions. When sampling on multiple events, branch stack sampling 270is enabled for all the sampling events. The sampled branch type is the same for all events. 271The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k 272Note that this feature may not be available on all processors. 273 274--weight:: 275Enable weightened sampling. An additional weight is recorded per sample and can be 276displayed with the weight and local_weight sort keys. This currently works for TSX 277abort events and some memory events in precise mode on modern Intel CPUs. 278 279--transaction:: 280Record transaction flags for transaction related events. 281 282--per-thread:: 283Use per-thread mmaps. By default per-cpu mmaps are created. This option 284overrides that and uses per-thread mmaps. A side-effect of that is that 285inheritance is automatically disabled. --per-thread is ignored with a warning 286if combined with -a or -C options. 287 288-D:: 289--delay=:: 290After starting the program, wait msecs before measuring. This is useful to 291filter out the startup phase of the program, which is often very different. 292 293-I:: 294--intr-regs:: 295Capture machine state (registers) at interrupt, i.e., on counter overflows for 296each sample. List of captured registers depends on the architecture. This option 297is off by default. It is possible to select the registers to sample using their 298symbolic names, e.g. on x86, ax, si. To list the available registers use 299--intr-regs=\?. To name registers, pass a comma separated list such as 300--intr-regs=ax,bx. The list of register is architecture dependent. 301 302 303--running-time:: 304Record running and enabled time for read events (:S) 305 306-k:: 307--clockid:: 308Sets the clock id to use for the various time fields in the perf_event_type 309records. See clock_gettime(). In particular CLOCK_MONOTONIC and 310CLOCK_MONOTONIC_RAW are supported, some events might also allow 311CLOCK_BOOTTIME, CLOCK_REALTIME and CLOCK_TAI. 312 313-S:: 314--snapshot:: 315Select AUX area tracing Snapshot Mode. This option is valid only with an 316AUX area tracing event. Optionally the number of bytes to capture per 317snapshot can be specified. In Snapshot Mode, trace data is captured only when 318signal SIGUSR2 is received. 319 320--proc-map-timeout:: 321When processing pre-existing threads /proc/XXX/mmap, it may take a long time, 322because the file may be huge. A time out is needed in such cases. 323This option sets the time out limit. The default value is 500 ms. 324 325--switch-events:: 326Record context switch events i.e. events of type PERF_RECORD_SWITCH or 327PERF_RECORD_SWITCH_CPU_WIDE. 328 329--clang-path=PATH:: 330Path to clang binary to use for compiling BPF scriptlets. 331(enabled when BPF support is on) 332 333--clang-opt=OPTIONS:: 334Options passed to clang when compiling BPF scriptlets. 335(enabled when BPF support is on) 336 337--vmlinux=PATH:: 338Specify vmlinux path which has debuginfo. 339(enabled when BPF prologue is on) 340 341--buildid-all:: 342Record build-id of all DSOs regardless whether it's actually hit or not. 343 344--all-kernel:: 345Configure all used events to run in kernel space. 346 347--all-user:: 348Configure all used events to run in user space. 349 350--timestamp-filename 351Append timestamp to output file name. 352 353--switch-output:: 354Generate multiple perf.data files, timestamp prefixed, switching to a new one 355when receiving a SIGUSR2. 356 357A possible use case is to, given an external event, slice the perf.data file 358that gets then processed, possibly via a perf script, to decide if that 359particular perf.data snapshot should be kept or not. 360 361Implies --timestamp-filename, --no-buildid and --no-buildid-cache. 362 363SEE ALSO 364-------- 365linkperf:perf-stat[1], linkperf:perf-list[1] 366