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