1perf-top(1) 2=========== 3 4NAME 5---- 6perf-top - System profiling tool. 7 8SYNOPSIS 9-------- 10[verse] 11'perf top' [-e <EVENT> | --event=EVENT] [<options>] 12 13DESCRIPTION 14----------- 15This command generates and displays a performance counter profile in real time. 16 17 18OPTIONS 19------- 20-a:: 21--all-cpus:: 22 System-wide collection. (default) 23 24-c <count>:: 25--count=<count>:: 26 Event period to sample. 27 28-C <cpu-list>:: 29--cpu=<cpu>:: 30Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a 31comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2. 32Default is to monitor all CPUS. 33 34-d <seconds>:: 35--delay=<seconds>:: 36 Number of seconds to delay between refreshes. 37 38-e <event>:: 39--event=<event>:: 40 Select the PMU event. Selection can be a symbolic event name 41 (use 'perf list' to list all events) or a raw PMU 42 event (eventsel+umask) in the form of rNNN where NNN is a 43 hexadecimal event descriptor. 44 45-E <entries>:: 46--entries=<entries>:: 47 Display this many functions. 48 49-f <count>:: 50--count-filter=<count>:: 51 Only display functions with more events than this. 52 53--group:: 54 Put the counters into a counter group. 55 56-F <freq>:: 57--freq=<freq>:: 58 Profile at this frequency. Use 'max' to use the currently maximum 59 allowed frequency, i.e. the value in the kernel.perf_event_max_sample_rate 60 sysctl. 61 62-i:: 63--inherit:: 64 Child tasks do not inherit counters. 65 66-k <path>:: 67--vmlinux=<path>:: 68 Path to vmlinux. Required for annotation functionality. 69 70--ignore-vmlinux:: 71 Ignore vmlinux files. 72 73-m <pages>:: 74--mmap-pages=<pages>:: 75 Number of mmap data pages (must be a power of two) or size 76 specification with appended unit character - B/K/M/G. The 77 size is rounded up to have nearest pages power of two value. 78 79-p <pid>:: 80--pid=<pid>:: 81 Profile events on existing Process ID (comma separated list). 82 83-t <tid>:: 84--tid=<tid>:: 85 Profile events on existing thread ID (comma separated list). 86 87-u:: 88--uid=:: 89 Record events in threads owned by uid. Name or number. 90 91-r <priority>:: 92--realtime=<priority>:: 93 Collect data with this RT SCHED_FIFO priority. 94 95--sym-annotate=<symbol>:: 96 Annotate this symbol. 97 98-K:: 99--hide_kernel_symbols:: 100 Hide kernel symbols. 101 102-U:: 103--hide_user_symbols:: 104 Hide user symbols. 105 106--demangle-kernel:: 107 Demangle kernel symbols. 108 109-D:: 110--dump-symtab:: 111 Dump the symbol table used for profiling. 112 113-v:: 114--verbose:: 115 Be more verbose (show counter open errors, etc). 116 117-z:: 118--zero:: 119 Zero history across display updates. 120 121-s:: 122--sort:: 123 Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight, 124 local_weight, abort, in_tx, transaction, overhead, sample, period. 125 Please see description of --sort in the perf-report man page. 126 127--fields=:: 128 Specify output field - multiple keys can be specified in CSV format. 129 Following fields are available: 130 overhead, overhead_sys, overhead_us, overhead_children, sample and period. 131 Also it can contain any sort key(s). 132 133 By default, every sort keys not specified in --field will be appended 134 automatically. 135 136-n:: 137--show-nr-samples:: 138 Show a column with the number of samples. 139 140--show-total-period:: 141 Show a column with the sum of periods. 142 143--dsos:: 144 Only consider symbols in these dsos. This option will affect the 145 percentage of the overhead column. See --percentage for more info. 146 147--comms:: 148 Only consider symbols in these comms. This option will affect the 149 percentage of the overhead column. See --percentage for more info. 150 151--symbols:: 152 Only consider these symbols. This option will affect the 153 percentage of the overhead column. See --percentage for more info. 154 155-M:: 156--disassembler-style=:: Set disassembler style for objdump. 157 158--source:: 159 Interleave source code with assembly code. Enabled by default, 160 disable with --no-source. 161 162--asm-raw:: 163 Show raw instruction encoding of assembly instructions. 164 165-g:: 166 Enables call-graph (stack chain/backtrace) recording. 167 168--call-graph [mode,type,min[,limit],order[,key][,branch]]:: 169 Setup and enable call-graph (stack chain/backtrace) recording, 170 implies -g. See `--call-graph` section in perf-record and 171 perf-report man pages for details. 172 173--children:: 174 Accumulate callchain of children to parent entry so that then can 175 show up in the output. The output will have a new "Children" column 176 and will be sorted on the data. It requires -g/--call-graph option 177 enabled. See the `overhead calculation' section for more details. 178 Enabled by default, disable with --no-children. 179 180--max-stack:: 181 Set the stack depth limit when parsing the callchain, anything 182 beyond the specified depth will be ignored. This is a trade-off 183 between information loss and faster processing especially for 184 workloads that can have a very long callchain stack. 185 186 Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise. 187 188--ignore-callees=<regex>:: 189 Ignore callees of the function(s) matching the given regex. 190 This has the effect of collecting the callers of each such 191 function into one place in the call-graph tree. 192 193--percent-limit:: 194 Do not show entries which have an overhead under that percent. 195 (Default: 0). 196 197--percentage:: 198 Determine how to display the overhead percentage of filtered entries. 199 Filters can be applied by --comms, --dsos and/or --symbols options and 200 Zoom operations on the TUI (thread, dso, etc). 201 202 "relative" means it's relative to filtered entries only so that the 203 sum of shown entries will be always 100%. "absolute" means it retains 204 the original value before and after the filter is applied. 205 206-w:: 207--column-widths=<width[,width...]>:: 208 Force each column width to the provided list, for large terminal 209 readability. 0 means no limit (default behavior). 210 211--proc-map-timeout:: 212 When processing pre-existing threads /proc/XXX/mmap, it may take 213 a long time, because the file may be huge. A time out is needed 214 in such cases. 215 This option sets the time out limit. The default value is 500 ms. 216 217 218-b:: 219--branch-any:: 220 Enable taken branch stack sampling. Any type of taken branch may be sampled. 221 This is a shortcut for --branch-filter any. See --branch-filter for more infos. 222 223-j:: 224--branch-filter:: 225 Enable taken branch stack sampling. Each sample captures a series of consecutive 226 taken branches. The number of branches captured with each sample depends on the 227 underlying hardware, the type of branches of interest, and the executed code. 228 It is possible to select the types of branches captured by enabling filters. 229 For a full list of modifiers please see the perf record manpage. 230 231 The option requires at least one branch type among any, any_call, any_ret, ind_call, cond. 232 The privilege levels may be omitted, in which case, the privilege levels of the associated 233 event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege 234 levels are subject to permissions. When sampling on multiple events, branch stack sampling 235 is enabled for all the sampling events. The sampled branch type is the same for all events. 236 The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k 237 Note that this feature may not be available on all processors. 238 239--raw-trace:: 240 When displaying traceevent output, do not use print fmt or plugins. 241 242--hierarchy:: 243 Enable hierarchy output. 244 245--force:: 246 Don't do ownership validation. 247 248--num-thread-synthesize:: 249 The number of threads to run when synthesizing events for existing processes. 250 By default, the number of threads equals to the number of online CPUs. 251 252INTERACTIVE PROMPTING KEYS 253-------------------------- 254 255[d]:: 256 Display refresh delay. 257 258[e]:: 259 Number of entries to display. 260 261[E]:: 262 Event to display when multiple counters are active. 263 264[f]:: 265 Profile display filter (>= hit count). 266 267[F]:: 268 Annotation display filter (>= % of total). 269 270[s]:: 271 Annotate symbol. 272 273[S]:: 274 Stop annotation, return to full profile display. 275 276[K]:: 277 Hide kernel symbols. 278 279[U]:: 280 Hide user symbols. 281 282[z]:: 283 Toggle event count zeroing across display updates. 284 285[qQ]:: 286 Quit. 287 288Pressing any unmapped key displays a menu, and prompts for input. 289 290include::callchain-overhead-calculation.txt[] 291 292SEE ALSO 293-------- 294linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1] 295