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      1 perf-stat(1)
      2 ============
      3 
      4 NAME
      5 ----
      6 perf-stat - Run a command and gather performance counter statistics
      7 
      8 SYNOPSIS
      9 --------
     10 [verse]
     11 'perf stat' [-e <EVENT> | --event=EVENT] [-a] <command>
     12 'perf stat' [-e <EVENT> | --event=EVENT] [-a] -- <command> [<options>]
     13 
     14 DESCRIPTION
     15 -----------
     16 This command runs a command and gathers performance counter statistics
     17 from it.
     18 
     19 
     20 OPTIONS
     21 -------
     22 <command>...::
     23 	Any command you can specify in a shell.
     24 
     25 
     26 -e::
     27 --event=::
     28 	Select the PMU event. Selection can be a symbolic event name
     29 	(use 'perf list' to list all events) or a raw PMU
     30 	event (eventsel+umask) in the form of rNNN where NNN is a
     31 	 hexadecimal event descriptor.
     32 
     33 -i::
     34 --no-inherit::
     35         child tasks do not inherit counters
     36 -p::
     37 --pid=<pid>::
     38         stat events on existing process id (comma separated list)
     39 
     40 -t::
     41 --tid=<tid>::
     42         stat events on existing thread id (comma separated list)
     43 
     44 
     45 -a::
     46 --all-cpus::
     47         system-wide collection from all CPUs
     48 
     49 -c::
     50 --scale::
     51 	scale/normalize counter values
     52 
     53 -r::
     54 --repeat=<n>::
     55 	repeat command and print average + stddev (max: 100). 0 means forever.
     56 
     57 -B::
     58 --big-num::
     59         print large numbers with thousands' separators according to locale
     60 
     61 -C::
     62 --cpu=::
     63 Count only on the list of CPUs provided. Multiple CPUs can be provided as a
     64 comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
     65 In per-thread mode, this option is ignored. The -a option is still necessary
     66 to activate system-wide monitoring. Default is to count on all CPUs.
     67 
     68 -A::
     69 --no-aggr::
     70 Do not aggregate counts across all monitored CPUs in system-wide mode (-a).
     71 This option is only valid in system-wide mode.
     72 
     73 -n::
     74 --null::
     75         null run - don't start any counters
     76 
     77 -v::
     78 --verbose::
     79         be more verbose (show counter open errors, etc)
     80 
     81 -x SEP::
     82 --field-separator SEP::
     83 print counts using a CSV-style output to make it easy to import directly into
     84 spreadsheets. Columns are separated by the string specified in SEP.
     85 
     86 -G name::
     87 --cgroup name::
     88 monitor only in the container (cgroup) called "name". This option is available only
     89 in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
     90 container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
     91 can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
     92 to first event, second cgroup to second event and so on. It is possible to provide
     93 an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
     94 corresponding events, i.e., they always refer to events defined earlier on the command
     95 line.
     96 
     97 -o file::
     98 --output file::
     99 Print the output into the designated file.
    100 
    101 --append::
    102 Append to the output file designated with the -o option. Ignored if -o is not specified.
    103 
    104 --log-fd::
    105 
    106 Log output to fd, instead of stderr.  Complementary to --output, and mutually exclusive
    107 with it.  --append may be used here.  Examples:
    108      3>results  perf stat --log-fd 3          -- $cmd
    109      3>>results perf stat --log-fd 3 --append -- $cmd
    110 
    111 --pre::
    112 --post::
    113 	Pre and post measurement hooks, e.g.:
    114 
    115 perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage
    116 
    117 -I msecs::
    118 --interval-print msecs::
    119 	Print count deltas every N milliseconds (minimum: 100ms)
    120 	example: perf stat -I 1000 -e cycles -a sleep 5
    121 
    122 --per-socket::
    123 Aggregate counts per processor socket for system-wide mode measurements.  This
    124 is a useful mode to detect imbalance between sockets.  To enable this mode,
    125 use --per-socket in addition to -a. (system-wide).  The output includes the
    126 socket number and the number of online processors on that socket. This is
    127 useful to gauge the amount of aggregation.
    128 
    129 --per-core::
    130 Aggregate counts per physical processor for system-wide mode measurements.  This
    131 is a useful mode to detect imbalance between physical cores.  To enable this mode,
    132 use --per-core in addition to -a. (system-wide).  The output includes the
    133 core number and the number of online logical processors on that physical processor.
    134 
    135 -D msecs::
    136 --initial-delay msecs::
    137 After starting the program, wait msecs before measuring. This is useful to
    138 filter out the startup phase of the program, which is often very different.
    139 
    140 EXAMPLES
    141 --------
    142 
    143 $ perf stat -- make -j
    144 
    145  Performance counter stats for 'make -j':
    146 
    147     8117.370256  task clock ticks     #      11.281 CPU utilization factor
    148             678  context switches     #       0.000 M/sec
    149             133  CPU migrations       #       0.000 M/sec
    150          235724  pagefaults           #       0.029 M/sec
    151     24821162526  CPU cycles           #    3057.784 M/sec
    152     18687303457  instructions         #    2302.138 M/sec
    153       172158895  cache references     #      21.209 M/sec
    154        27075259  cache misses         #       3.335 M/sec
    155 
    156  Wall-clock time elapsed:   719.554352 msecs
    157 
    158 SEE ALSO
    159 --------
    160 linkperf:perf-top[1], linkperf:perf-list[1]
    161