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