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. 59 60-i:: 61--inherit:: 62 Child tasks do not inherit counters. 63 64-k <path>:: 65--vmlinux=<path>:: 66 Path to vmlinux. Required for annotation functionality. 67 68-m <pages>:: 69--mmap-pages=<pages>:: 70 Number of mmap data pages (must be a power of two) or size 71 specification with appended unit character - B/K/M/G. The 72 size is rounded up to have nearest pages power of two value. 73 74-p <pid>:: 75--pid=<pid>:: 76 Profile events on existing Process ID (comma separated list). 77 78-t <tid>:: 79--tid=<tid>:: 80 Profile events on existing thread ID (comma separated list). 81 82-u:: 83--uid=:: 84 Record events in threads owned by uid. Name or number. 85 86-r <priority>:: 87--realtime=<priority>:: 88 Collect data with this RT SCHED_FIFO priority. 89 90--sym-annotate=<symbol>:: 91 Annotate this symbol. 92 93-K:: 94--hide_kernel_symbols:: 95 Hide kernel symbols. 96 97-U:: 98--hide_user_symbols:: 99 Hide user symbols. 100 101--demangle-kernel:: 102 Demangle kernel symbols. 103 104-D:: 105--dump-symtab:: 106 Dump the symbol table used for profiling. 107 108-v:: 109--verbose:: 110 Be more verbose (show counter open errors, etc). 111 112-z:: 113--zero:: 114 Zero history across display updates. 115 116-s:: 117--sort:: 118 Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight, 119 local_weight, abort, in_tx, transaction, overhead, sample, period. 120 Please see description of --sort in the perf-report man page. 121 122--fields=:: 123 Specify output field - multiple keys can be specified in CSV format. 124 Following fields are available: 125 overhead, overhead_sys, overhead_us, overhead_children, sample and period. 126 Also it can contain any sort key(s). 127 128 By default, every sort keys not specified in --field will be appended 129 automatically. 130 131-n:: 132--show-nr-samples:: 133 Show a column with the number of samples. 134 135--show-total-period:: 136 Show a column with the sum of periods. 137 138--dsos:: 139 Only consider symbols in these dsos. This option will affect the 140 percentage of the overhead column. See --percentage for more info. 141 142--comms:: 143 Only consider symbols in these comms. This option will affect the 144 percentage of the overhead column. See --percentage for more info. 145 146--symbols:: 147 Only consider these symbols. This option will affect the 148 percentage of the overhead column. See --percentage for more info. 149 150-M:: 151--disassembler-style=:: Set disassembler style for objdump. 152 153--source:: 154 Interleave source code with assembly code. Enabled by default, 155 disable with --no-source. 156 157--asm-raw:: 158 Show raw instruction encoding of assembly instructions. 159 160-g:: 161 Enables call-graph (stack chain/backtrace) recording. 162 163--call-graph [mode,type,min[,limit],order[,key][,branch]]:: 164 Setup and enable call-graph (stack chain/backtrace) recording, 165 implies -g. See `--call-graph` section in perf-record and 166 perf-report man pages for details. 167 168--children:: 169 Accumulate callchain of children to parent entry so that then can 170 show up in the output. The output will have a new "Children" column 171 and will be sorted on the data. It requires -g/--call-graph option 172 enabled. See the `overhead calculation' section for more details. 173 174--max-stack:: 175 Set the stack depth limit when parsing the callchain, anything 176 beyond the specified depth will be ignored. This is a trade-off 177 between information loss and faster processing especially for 178 workloads that can have a very long callchain stack. 179 180 Default: 127 181 182--ignore-callees=<regex>:: 183 Ignore callees of the function(s) matching the given regex. 184 This has the effect of collecting the callers of each such 185 function into one place in the call-graph tree. 186 187--percent-limit:: 188 Do not show entries which have an overhead under that percent. 189 (Default: 0). 190 191--percentage:: 192 Determine how to display the overhead percentage of filtered entries. 193 Filters can be applied by --comms, --dsos and/or --symbols options and 194 Zoom operations on the TUI (thread, dso, etc). 195 196 "relative" means it's relative to filtered entries only so that the 197 sum of shown entries will be always 100%. "absolute" means it retains 198 the original value before and after the filter is applied. 199 200-w:: 201--column-widths=<width[,width...]>:: 202 Force each column width to the provided list, for large terminal 203 readability. 0 means no limit (default behavior). 204 205--proc-map-timeout:: 206 When processing pre-existing threads /proc/XXX/mmap, it may take 207 a long time, because the file may be huge. A time out is needed 208 in such cases. 209 This option sets the time out limit. The default value is 500 ms. 210 211 212-b:: 213--branch-any:: 214 Enable taken branch stack sampling. Any type of taken branch may be sampled. 215 This is a shortcut for --branch-filter any. See --branch-filter for more infos. 216 217-j:: 218--branch-filter:: 219 Enable taken branch stack sampling. Each sample captures a series of consecutive 220 taken branches. The number of branches captured with each sample depends on the 221 underlying hardware, the type of branches of interest, and the executed code. 222 It is possible to select the types of branches captured by enabling filters. 223 For a full list of modifiers please see the perf record manpage. 224 225 The option requires at least one branch type among any, any_call, any_ret, ind_call, cond. 226 The privilege levels may be omitted, in which case, the privilege levels of the associated 227 event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege 228 levels are subject to permissions. When sampling on multiple events, branch stack sampling 229 is enabled for all the sampling events. The sampled branch type is the same for all events. 230 The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k 231 Note that this feature may not be available on all processors. 232 233INTERACTIVE PROMPTING KEYS 234-------------------------- 235 236[d]:: 237 Display refresh delay. 238 239[e]:: 240 Number of entries to display. 241 242[E]:: 243 Event to display when multiple counters are active. 244 245[f]:: 246 Profile display filter (>= hit count). 247 248[F]:: 249 Annotation display filter (>= % of total). 250 251[s]:: 252 Annotate symbol. 253 254[S]:: 255 Stop annotation, return to full profile display. 256 257[z]:: 258 Toggle event count zeroing across display updates. 259 260[qQ]:: 261 Quit. 262 263Pressing any unmapped key displays a menu, and prompts for input. 264 265include::callchain-overhead-calculation.txt[] 266 267SEE ALSO 268-------- 269linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1] 270