1perf-stat(1)
2============
3
4NAME
5----
6perf-stat - Run a command and gather performance counter statistics
7
8SYNOPSIS
9--------
10[verse]
11'perf stat' [-e <EVENT> | --event=EVENT] [-a] <command>
12'perf stat' [-e <EVENT> | --event=EVENT] [-a] -- <command> [<options>]
13
14DESCRIPTION
15-----------
16This command runs a command and gathers performance counter statistics
17from it.
18
19
20OPTIONS
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=::
63Count only on the list of CPUs provided. Multiple CPUs can be provided as a
64comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
65In per-thread mode, this option is ignored. The -a option is still necessary
66to activate system-wide monitoring. Default is to count on all CPUs.
67
68-A::
69--no-aggr::
70Do not aggregate counts across all monitored CPUs in system-wide mode (-a).
71This 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::
83print counts using a CSV-style output to make it easy to import directly into
84spreadsheets. Columns are separated by the string specified in SEP.
85
86-G name::
87--cgroup name::
88monitor only in the container (cgroup) called "name". This option is available only
89in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
90container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
91can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
92to first event, second cgroup to second event and so on. It is possible to provide
93an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
94corresponding events, i.e., they always refer to events defined earlier on the command
95line.
96
97-o file::
98--output file::
99Print the output into the designated file.
100
101--append::
102Append to the output file designated with the -o option. Ignored if -o is not specified.
103
104--log-fd::
105
106Log output to fd, instead of stderr.  Complementary to --output, and mutually exclusive
107with 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 -- $cmd
110
111--pre::
112--post::
113	Pre and post measurement hooks, e.g.:
114
115perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage
116
117-I msecs::
118--interval-print msecs::
119	Print count deltas every N milliseconds (minimum: 100ms)
120	example: perf stat -I 1000 -e cycles -a sleep 5
121
122--per-socket::
123Aggregate counts per processor socket for system-wide mode measurements.  This
124is a useful mode to detect imbalance between sockets.  To enable this mode,
125use --per-socket in addition to -a. (system-wide).  The output includes the
126socket number and the number of online processors on that socket. This is
127useful to gauge the amount of aggregation.
128
129--per-core::
130Aggregate counts per physical processor for system-wide mode measurements.  This
131is a useful mode to detect imbalance between physical cores.  To enable this mode,
132use --per-core in addition to -a. (system-wide).  The output includes the
133core number and the number of online logical processors on that physical processor.
134
135-D msecs::
136--delay msecs::
137After starting the program, wait msecs before measuring. This is useful to
138filter out the startup phase of the program, which is often very different.
139
140-T::
141--transaction::
142
143Print statistics of transactional execution if supported.
144
145EXAMPLES
146--------
147
148$ perf stat -- make -j
149
150 Performance counter stats for 'make -j':
151
152    8117.370256  task clock ticks     #      11.281 CPU utilization factor
153            678  context switches     #       0.000 M/sec
154            133  CPU migrations       #       0.000 M/sec
155         235724  pagefaults           #       0.029 M/sec
156    24821162526  CPU cycles           #    3057.784 M/sec
157    18687303457  instructions         #    2302.138 M/sec
158      172158895  cache references     #      21.209 M/sec
159       27075259  cache misses         #       3.335 M/sec
160
161 Wall-clock time elapsed:   719.554352 msecs
162
163SEE ALSO
164--------
165linkperf:perf-top[1], linkperf:perf-list[1]
166