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)

           •   a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a hexadecimal
               event descriptor.

           •   a symbolically formed event like pmu/param1=0x3,param2/ where param1 and param2
               are defined as formats for the PMU in
               /sys/bus/event_sources/devices/<pmu>/format/*

           •   a symbolically formed event like pmu/config=M,config1=N,config2=K/ where M, N, K
               are numbers (in decimal, hex, octal format). Acceptable values for each of config,
               config1 and config2 parameters are defined by corresponding entries in
               /sys/bus/event_sources/devices/<pmu>/format/*

       -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: 10ms) The overhead percentage could
           be high in some cases, for instance with small, sub 100ms intervals. Use with caution.
           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.

       --per-thread
           Aggregate counts per monitored threads, when monitoring threads (-t option) or
           processes (-p option).

       -D msecs, --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.

       -T, --transaction
           Print statistics of transactional execution if supported.

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)