| PERF-STAT(1) | perf Manual | PERF-STAT(1) |
NAME¶
perf-stat - Run a command and gather performance counter statistics
SYNOPSIS¶
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¶
| 05/02/2024 | perf |