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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-d::
54--detailed::
55	print more detailed statistics, can be specified up to 3 times
56
57	   -d:          detailed events, L1 and LLC data cache
58        -d -d:     more detailed events, dTLB and iTLB events
59     -d -d -d:     very detailed events, adding prefetch events
60
61-r::
62--repeat=<n>::
63	repeat command and print average + stddev (max: 100). 0 means forever.
64
65-B::
66--big-num::
67        print large numbers with thousands' separators according to locale
68
69-C::
70--cpu=::
71Count only on the list of CPUs provided. Multiple CPUs can be provided as a
72comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
73In per-thread mode, this option is ignored. The -a option is still necessary
74to activate system-wide monitoring. Default is to count on all CPUs.
75
76-A::
77--no-aggr::
78Do not aggregate counts across all monitored CPUs in system-wide mode (-a).
79This option is only valid in system-wide mode.
80
81-n::
82--null::
83        null run - don't start any counters
84
85-v::
86--verbose::
87        be more verbose (show counter open errors, etc)
88
89-x SEP::
90--field-separator SEP::
91print counts using a CSV-style output to make it easy to import directly into
92spreadsheets. Columns are separated by the string specified in SEP.
93
94-G name::
95--cgroup name::
96monitor only in the container (cgroup) called "name". This option is available only
97in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
98container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
99can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
100to first event, second cgroup to second event and so on. It is possible to provide
101an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
102corresponding events, i.e., they always refer to events defined earlier on the command
103line.
104
105-o file::
106--output file::
107Print the output into the designated file.
108
109--append::
110Append to the output file designated with the -o option. Ignored if -o is not specified.
111
112--log-fd::
113
114Log output to fd, instead of stderr.  Complementary to --output, and mutually exclusive
115with it.  --append may be used here.  Examples:
116     3>results  perf stat --log-fd 3          -- $cmd
117     3>>results perf stat --log-fd 3 --append -- $cmd
118
119--pre::
120--post::
121	Pre and post measurement hooks, e.g.:
122
123perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage
124
125-I msecs::
126--interval-print msecs::
127	Print count deltas every N milliseconds (minimum: 100ms)
128	example: perf stat -I 1000 -e cycles -a sleep 5
129
130--per-socket::
131Aggregate counts per processor socket for system-wide mode measurements.  This
132is a useful mode to detect imbalance between sockets.  To enable this mode,
133use --per-socket in addition to -a. (system-wide).  The output includes the
134socket number and the number of online processors on that socket. This is
135useful to gauge the amount of aggregation.
136
137--per-core::
138Aggregate counts per physical processor for system-wide mode measurements.  This
139is a useful mode to detect imbalance between physical cores.  To enable this mode,
140use --per-core in addition to -a. (system-wide).  The output includes the
141core number and the number of online logical processors on that physical processor.
142
143-D msecs::
144--delay msecs::
145After starting the program, wait msecs before measuring. This is useful to
146filter out the startup phase of the program, which is often very different.
147
148-T::
149--transaction::
150
151Print statistics of transactional execution if supported.
152
153EXAMPLES
154--------
155
156$ perf stat -- make -j
157
158 Performance counter stats for 'make -j':
159
160    8117.370256  task clock ticks     #      11.281 CPU utilization factor
161            678  context switches     #       0.000 M/sec
162            133  CPU migrations       #       0.000 M/sec
163         235724  pagefaults           #       0.029 M/sec
164    24821162526  CPU cycles           #    3057.784 M/sec
165    18687303457  instructions         #    2302.138 M/sec
166      172158895  cache references     #      21.209 M/sec
167       27075259  cache misses         #       3.335 M/sec
168
169 Wall-clock time elapsed:   719.554352 msecs
170
171SEE ALSO
172--------
173linkperf:perf-top[1], linkperf:perf-list[1]
174