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:
29
30	- a symbolic event name (use 'perf list' to list all events)
31
32	- a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
33	  hexadecimal event descriptor.
34
35	- a symbolically formed event like 'pmu/param1=0x3,param2/' where
36	  param1 and param2 are defined as formats for the PMU in
37	  /sys/bus/event_sources/devices/<pmu>/format/*
38
39	- a symbolically formed event like 'pmu/config=M,config1=N,config2=K/'
40	  where M, N, K are numbers (in decimal, hex, octal format).
41	  Acceptable values for each of 'config', 'config1' and 'config2'
42	  parameters are defined by corresponding entries in
43	  /sys/bus/event_sources/devices/<pmu>/format/*
44
45-i::
46--no-inherit::
47        child tasks do not inherit counters
48-p::
49--pid=<pid>::
50        stat events on existing process id (comma separated list)
51
52-t::
53--tid=<tid>::
54        stat events on existing thread id (comma separated list)
55
56
57-a::
58--all-cpus::
59        system-wide collection from all CPUs
60
61-c::
62--scale::
63	scale/normalize counter values
64
65-d::
66--detailed::
67	print more detailed statistics, can be specified up to 3 times
68
69	   -d:          detailed events, L1 and LLC data cache
70        -d -d:     more detailed events, dTLB and iTLB events
71     -d -d -d:     very detailed events, adding prefetch events
72
73-r::
74--repeat=<n>::
75	repeat command and print average + stddev (max: 100). 0 means forever.
76
77-B::
78--big-num::
79        print large numbers with thousands' separators according to locale
80
81-C::
82--cpu=::
83Count only on the list of CPUs provided. Multiple CPUs can be provided as a
84comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
85In per-thread mode, this option is ignored. The -a option is still necessary
86to activate system-wide monitoring. Default is to count on all CPUs.
87
88-A::
89--no-aggr::
90Do not aggregate counts across all monitored CPUs in system-wide mode (-a).
91This option is only valid in system-wide mode.
92
93-n::
94--null::
95        null run - don't start any counters
96
97-v::
98--verbose::
99        be more verbose (show counter open errors, etc)
100
101-x SEP::
102--field-separator SEP::
103print counts using a CSV-style output to make it easy to import directly into
104spreadsheets. Columns are separated by the string specified in SEP.
105
106-G name::
107--cgroup name::
108monitor only in the container (cgroup) called "name". This option is available only
109in per-cpu mode. The cgroup filesystem must be mounted. All threads belonging to
110container "name" are monitored when they run on the monitored CPUs. Multiple cgroups
111can be provided. Each cgroup is applied to the corresponding event, i.e., first cgroup
112to first event, second cgroup to second event and so on. It is possible to provide
113an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must have
114corresponding events, i.e., they always refer to events defined earlier on the command
115line.
116
117-o file::
118--output file::
119Print the output into the designated file.
120
121--append::
122Append to the output file designated with the -o option. Ignored if -o is not specified.
123
124--log-fd::
125
126Log output to fd, instead of stderr.  Complementary to --output, and mutually exclusive
127with it.  --append may be used here.  Examples:
128     3>results  perf stat --log-fd 3          -- $cmd
129     3>>results perf stat --log-fd 3 --append -- $cmd
130
131--pre::
132--post::
133	Pre and post measurement hooks, e.g.:
134
135perf stat --repeat 10 --null --sync --pre 'make -s O=defconfig-build/clean' -- make -s -j64 O=defconfig-build/ bzImage
136
137-I msecs::
138--interval-print msecs::
139Print count deltas every N milliseconds (minimum: 10ms)
140The overhead percentage could be high in some cases, for instance with small, sub 100ms intervals.  Use with caution.
141	example: 'perf stat -I 1000 -e cycles -a sleep 5'
142
143--per-socket::
144Aggregate counts per processor socket for system-wide mode measurements.  This
145is a useful mode to detect imbalance between sockets.  To enable this mode,
146use --per-socket in addition to -a. (system-wide).  The output includes the
147socket number and the number of online processors on that socket. This is
148useful to gauge the amount of aggregation.
149
150--per-core::
151Aggregate counts per physical processor for system-wide mode measurements.  This
152is a useful mode to detect imbalance between physical cores.  To enable this mode,
153use --per-core in addition to -a. (system-wide).  The output includes the
154core number and the number of online logical processors on that physical processor.
155
156--per-thread::
157Aggregate counts per monitored threads, when monitoring threads (-t option)
158or processes (-p option).
159
160-D msecs::
161--delay msecs::
162After starting the program, wait msecs before measuring. This is useful to
163filter out the startup phase of the program, which is often very different.
164
165-T::
166--transaction::
167
168Print statistics of transactional execution if supported.
169
170EXAMPLES
171--------
172
173$ perf stat -- make -j
174
175 Performance counter stats for 'make -j':
176
177    8117.370256  task clock ticks     #      11.281 CPU utilization factor
178            678  context switches     #       0.000 M/sec
179            133  CPU migrations       #       0.000 M/sec
180         235724  pagefaults           #       0.029 M/sec
181    24821162526  CPU cycles           #    3057.784 M/sec
182    18687303457  instructions         #    2302.138 M/sec
183      172158895  cache references     #      21.209 M/sec
184       27075259  cache misses         #       3.335 M/sec
185
186 Wall-clock time elapsed:   719.554352 msecs
187
188SEE ALSO
189--------
190linkperf:perf-top[1], linkperf:perf-list[1]
191