tools/perf/Documentation/perf-top.txt

   1 perf-top(1)
   2 ===========
   3
   4 NAME
   5 ----
   6 perf-top - System profiling tool.
   7
   8 SYNOPSIS
   9 --------
  10 [verse]
  11 'perf top' [-e <EVENT> | --event=EVENT] [<options>]
  12
  13 DESCRIPTION
  14 -----------
  15 This command generates and displays a performance counter profile in real time.
  16
  17
  18 OPTIONS
  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>::
  30 Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a
  31 comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
  32 Default 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
 211 INTERACTIVE 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
 241 Pressing any unmapped key displays a menu, and prompts for input.
 242
 243 include::callchain-overhead-calculation.txt[]
 244
 245 SEE ALSO
 246 --------
 247 linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1]