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:: 164 Setup and enable call-graph (stack chain/backtrace) recording, 165 implies -g. 166 167--children:: 168 Accumulate callchain of children to parent entry so that then can 169 show up in the output. The output will have a new "Children" column 170 and will be sorted on the data. It requires -g/--call-graph option 171 enabled. See the `overhead calculation' section for more details. 172 173--max-stack:: 174 Set the stack depth limit when parsing the callchain, anything 175 beyond the specified depth will be ignored. This is a trade-off 176 between information loss and faster processing especially for 177 workloads that can have a very long callchain stack. 178 179 Default: 127 180 181--ignore-callees=<regex>:: 182 Ignore callees of the function(s) matching the given regex. 183 This has the effect of collecting the callers of each such 184 function into one place in the call-graph tree. 185 186--percent-limit:: 187 Do not show entries which have an overhead under that percent. 188 (Default: 0). 189 190--percentage:: 191 Determine how to display the overhead percentage of filtered entries. 192 Filters can be applied by --comms, --dsos and/or --symbols options and 193 Zoom operations on the TUI (thread, dso, etc). 194 195 "relative" means it's relative to filtered entries only so that the 196 sum of shown entries will be always 100%. "absolute" means it retains 197 the original value before and after the filter is applied. 198 199-w:: 200--column-widths=<width[,width...]>:: 201 Force each column width to the provided list, for large terminal 202 readability. 0 means no limit (default behavior). 203 204--proc-map-timeout:: 205 When processing pre-existing threads /proc/XXX/mmap, it may take 206 a long time, because the file may be huge. A time out is needed 207 in such cases. 208 This option sets the time out limit. The default value is 500 ms. 209 210 211INTERACTIVE PROMPTING KEYS 212-------------------------- 213 214[d]:: 215 Display refresh delay. 216 217[e]:: 218 Number of entries to display. 219 220[E]:: 221 Event to display when multiple counters are active. 222 223[f]:: 224 Profile display filter (>= hit count). 225 226[F]:: 227 Annotation display filter (>= % of total). 228 229[s]:: 230 Annotate symbol. 231 232[S]:: 233 Stop annotation, return to full profile display. 234 235[z]:: 236 Toggle event count zeroing across display updates. 237 238[qQ]:: 239 Quit. 240 241Pressing any unmapped key displays a menu, and prompts for input. 242 243include::callchain-overhead-calculation.txt[] 244 245SEE ALSO 246-------- 247linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1] 248