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PERF-STAT(1)                      perf Manual                     PERF-STAT(1)



NAME
       perf-stat - Run a command and gather performance counter statistics

SYNOPSIS
       perf stat [-e <EVENT> | --event=EVENT] [-a] <command>
       perf stat [-e <EVENT> | --event=EVENT] [-a] -- <command> [<options>]

DESCRIPTION
       This command runs a command and gathers performance counter statistics from it.

OPTIONS
       <command>...
           Any command you can specify in a shell.

       -e, --event=
           Select the PMU event. Selection can be a symbolic event name (use perf list to list all events) or a raw
           PMU event (eventsel+umask) in the form of rNNN where NNN is a hexadecimal event descriptor.

       -i, --no-inherit
           child tasks do not inherit counters

       -p, --pid=<pid>
           stat events on existing process id (comma separated list)

       -t, --tid=<tid>
           stat events on existing thread id (comma separated list)

       -a, --all-cpus
           system-wide collection from all CPUs

       -c, --scale
           scale/normalize counter values

       -d, --detailed
           print more detailed statistics, can be specified up to 3 times

                     -d:          detailed events, L1 and LLC data cache
                  -d -d:     more detailed events, dTLB and iTLB events
               -d -d -d:     very detailed events, adding prefetch events

       -r, --repeat=<n>
           repeat command and print average + stddev (max: 100). 0 means forever.

       -B, --big-num
           print large numbers with thousands? separators according to locale

       -C, --cpu=
           Count only on the list of CPUs provided. Multiple CPUs can be provided as a comma-separated list with no
           space: 0,1. Ranges of CPUs are specified with -: 0-2. In per-thread mode, this option is ignored. The -a
           option is still necessary to activate system-wide monitoring. Default is to count on all CPUs.

       -A, --no-aggr
           Do not aggregate counts across all monitored CPUs in system-wide mode (-a). This option is only valid in
           system-wide mode.

       -n, --null
           null run - don't start any counters

       -v, --verbose
           be more verbose (show counter open errors, etc)

       -x SEP, --field-separator SEP
           print counts using a CSV-style output to make it easy to import directly into spreadsheets. Columns are
           separated by the string specified in SEP.

       -G name, --cgroup name
           monitor only in the container (cgroup) called "name". This option is available only in per-cpu mode. The
           cgroup filesystem must be mounted. All threads belonging to container "name" are monitored when they run on
           the monitored CPUs. Multiple cgroups can be provided. Each cgroup is applied to the corresponding event,
           i.e., first cgroup to first event, second cgroup to second event and so on. It is possible to provide an
           empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have corresponding events, i.e.,
           they always refer to events defined earlier on the command line.

       -o file, --output file
           Print the output into the designated file.

       --append
           Append to the output file designated with the -o option. Ignored if -o is not specified.

       --log-fd
           Log output to fd, instead of stderr. Complementary to --output, and mutually exclusive with it. --append
           may be used here. Examples: 3>results perf stat --log-fd 3  -- $cmd 3>>results perf stat --log-fd 3 --append
           -- $cmd

       --pre, --post
           Pre and post measurement hooks, e.g.:

       perf stat --repeat 10 --null --sync --pre make -s O=defconfig-build/clean -- make -s -j64 O=defconfig-build/
       bzImage

       -I msecs, --interval-print msecs
           Print count deltas every N milliseconds (minimum: 100ms) example: perf stat -I 1000 -e cycles -a sleep 5

       --per-socket
           Aggregate counts per processor socket for system-wide mode measurements. This is a useful mode to detect
           imbalance between sockets. To enable this mode, use --per-socket in addition to -a. (system-wide). The
           output includes the socket number and the number of online processors on that socket. This is useful to
           gauge the amount of aggregation.

       --per-core
           Aggregate counts per physical processor for system-wide mode measurements. This is a useful mode to detect
           imbalance between physical cores. To enable this mode, use --per-core in addition to -a. (system-wide). The
           output includes the core number and the number of online logical processors on that physical processor.

       -D msecs, --initial-delay msecs
           After starting the program, wait msecs before measuring. This is useful to filter out the startup phase of
           the program, which is often very different.

EXAMPLES
       $ perf stat -- make -j

           Performance counter stats for ?make -j?:

           8117.370256  task clock ticks     #      11.281 CPU utilization factor
                   678  context switches     #       0.000 M/sec
                   133  CPU migrations       #       0.000 M/sec
                235724  pagefaults           #       0.029 M/sec
           24821162526  CPU cycles           #    3057.784 M/sec
           18687303457  instructions         #    2302.138 M/sec
             172158895  cache references     #      21.209 M/sec
              27075259  cache misses         #       3.335 M/sec

           Wall-clock time elapsed:   719.554352 msecs

SEE ALSO
       perf-top(1), perf-list(1)



perf                              06/22/2017                      PERF-STAT(1)