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diff --git a/kernel/tools/perf/Documentation/perf-stat.txt b/kernel/tools/perf/Documentation/perf-stat.txt new file mode 100644 index 000000000..04e150d83 --- /dev/null +++ b/kernel/tools/perf/Documentation/perf-stat.txt @@ -0,0 +1,177 @@ +perf-stat(1) +============ + +NAME +---- +perf-stat - Run a command and gather performance counter statistics + +SYNOPSIS +-------- +[verse] +'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 + +-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 -- $cmd + +--pre:: +--post:: + Pre and post measurement hooks, e.g.: + +perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage + +-I msecs:: +--interval-print msecs:: + Print count deltas every N milliseconds (minimum: 100ms) + example: perf stat -I 1000 -e cycles -a sleep 5 + +--per-socket:: +Aggregate counts per processor socket for system-wide mode measurements. This +is a useful mode to detect imbalance between sockets. To enable this mode, +use --per-socket in addition to -a. (system-wide). The output includes the +socket number and the number of online processors on that socket. This is +useful to gauge the amount of aggregation. + +--per-core:: +Aggregate counts per physical processor for system-wide mode measurements. This +is a useful mode to detect imbalance between physical cores. To enable this mode, +use --per-core in addition to -a. (system-wide). The output includes the +core number and the number of online logical processors on that physical processor. + +-D msecs:: +--delay msecs:: +After starting the program, wait msecs before measuring. This is useful to +filter out the startup phase of the program, which is often very different. + +-T:: +--transaction:: + +Print statistics of transactional execution if supported. + +EXAMPLES +-------- + +$ 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 +-------- +linkperf:perf-top[1], linkperf:perf-list[1] |