<command>...
Any command you can specify in a shell.
record
See STAT RECORD.
report
See STAT REPORT.
-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 symbolic or raw PMU event followed by an optional colon
and a list of event modifiers, e.g., cpu-cycles:p. See
the perf-list(1) man page for details on event modifiers.
• a symbolically formed event like pmu/param1=0x3,param2/
where param1 and param2 are defined as formats for the
PMU in /sys/bus/event_source/devices/<pmu>/format/*
'percore' is a event qualifier that sums up the event counts for both
hardware threads in a core. For example:
perf stat -A -a -e cpu/event,percore=1/,otherevent ...
• 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_source/devices/<pmu>/format/*
Note that the last two syntaxes support prefix and glob matching in
the PMU name to simplify creation of events across multiple instances
of the same type of PMU in large systems (e.g. memory controller PMUs).
Multiple PMU instances are typical for uncore PMUs, so the prefix
'uncore_' is also ignored when performing this match.
-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)
-b, --bpf-prog
stat events on existing bpf program id (comma separated
list), requiring root rights. bpftool-prog could be used to
find program id all bpf programs in the system. For example:
# bpftool prog | head -n 1
17247: tracepoint name sys_enter tag 192d548b9d754067 gpl
# perf stat -e cycles,instructions --bpf-prog 17247 --timeout 1000
Performance counter stats for 'BPF program(s) 17247':
85,967 cycles
28,982 instructions # 0.34 insn per cycle
1.102235068 seconds time elapsed
--bpf-counters
Use BPF programs to aggregate readings from perf_events. This
allows multiple perf-stat sessions that are counting the same
metric (cycles, instructions, etc.) to share hardware
counters. To use BPF programs on common events by default,
use "perf config stat.bpf-counter-events=<list_of_events>".
--bpf-attr-map
With option "--bpf-counters", different perf-stat sessions
share information about shared BPF programs and maps via a
pinned hashmap. Use "--bpf-attr-map" to specify the path of
this pinned hashmap. The default path is
/sys/fs/bpf/perf_attr_map.
-a, --all-cpus
system-wide collection from all CPUs (default if no target is
specified)
--no-scale
Don't scale/normalize counter values
-d, --detailed
print more detailed statistics, can be specified up to 3
times
-d: detailed events, L1 and LLC data cache
-d -d: more detailed events, dTLB and iTLB events
-d -d -d: very detailed events, adding prefetch events
-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. Enabled by default. Use "--no-big-num" to disable.
Default setting can be changed with "perf config
stat.big-num=false".
-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.
-n, --null
null run - Don't start any counters.
This can be useful to measure just elapsed wall-clock time - or
to assess the raw overhead of perf stat itself, without running
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.
--table
Display time for each run (-r option), in a table format,
e.g.:
$ perf stat --null -r 5 --table perf bench sched pipe
Performance counter stats for 'perf bench sched pipe' (5 runs):
# Table of individual measurements:
5.189 (-0.293) #
5.189 (-0.294) #
5.186 (-0.296) #
5.663 (+0.181) ##
6.186 (+0.703) ####
# Final result:
5.483 +- 0.198 seconds time elapsed ( +- 3.62% )
-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. If the user wants to track multiple events
for a specific cgroup, the user can use -e e1 -e e2 -G
foo,foo or just use -e e1 -e e2 -G foo.
If wanting to monitor, say, cycles for a cgroup and also for
system wide, this command line can be used: perf stat -e cycles
-G cgroup_name -a -e cycles.
--for-each-cgroup name
Expand event list for each cgroup in "name" (allow multiple
cgroups separated by comma). It also support regex patterns
to match multiple groups. This has same effect that repeating
-e option and -G option for each event x name. This option
cannot be used with -G/--cgroup option.
-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 — $cmd
--control=fifo:ctl-fifo[,ack-fifo], --control=fd:ctl-fd[,ack-fd]
ctl-fifo / ack-fifo are opened and used as ctl-fd / ack-fd as
follows. Listen on ctl-fd descriptor for command to control
measurement (enable: enable events, disable: disable events).
Measurements can be started with events disabled using
--delay=-1 option. Optionally send control command completion
(ack\n) to ack-fd descriptor to synchronize with the
controlling process. Example of bash shell script to enable
and disable events during measurements:
#!/bin/bash
ctl_dir=/tmp/
ctl_fifo=${ctl_dir}perf_ctl.fifo
test -p ${ctl_fifo} && unlink ${ctl_fifo}
mkfifo ${ctl_fifo}
exec {ctl_fd}<>${ctl_fifo}
ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
mkfifo ${ctl_ack_fifo}
exec {ctl_fd_ack}<>${ctl_ack_fifo}
perf stat -D -1 -e cpu-cycles -a -I 1000 \
--control fd:${ctl_fd},${ctl_fd_ack} \
-- sleep 30 &
perf_pid=$!
sleep 5 && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
exec {ctl_fd_ack}>&-
unlink ${ctl_ack_fifo}
exec {ctl_fd}>&-
unlink ${ctl_fifo}
wait -n ${perf_pid}
exit $?
--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: 1ms) The
overhead percentage could be high in some cases, for instance
with small, sub 100ms intervals. Use with caution. example:
perf stat -I 1000 -e cycles -a sleep 5
If the metric exists, it is calculated by the counts generated in
this interval and the metric is printed after #.
--interval-count times
Print count deltas for fixed number of times. This option
should be used together with "-I" option. example: perf stat
-I 1000 --interval-count 2 -e cycles -a
--interval-clear
Clear the screen before next interval.
--timeout msecs
Stop the perf stat session and print count deltas after N
milliseconds (minimum: 10 ms). This option is not supported
with the "-I" option. example: perf stat --time 2000 -e
cycles -a
--metric-only
Only print computed metrics. Print them in a single line.
Don't show any raw values. Not supported with --per-thread.
--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-die
Aggregate counts per processor die for system-wide mode
measurements. This is a useful mode to detect imbalance
between dies. To enable this mode, use --per-die in addition
to -a. (system-wide). The output includes the die number and
the number of online processors on that die. 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.
--per-thread
Aggregate counts per monitored threads, when monitoring
threads (-t option) or processes (-p option).
--per-node
Aggregate counts per NUMA nodes for system-wide mode
measurements. This is a useful mode to detect imbalance
between NUMA nodes. To enable this mode, use --per-node in
addition to -a. (system-wide).
-D msecs, --delay msecs
After starting the program, wait msecs before measuring (-1:
start with events disabled). 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.
--metric-no-group
By default, events to compute a metric are placed in weak
groups. The group tries to enforce scheduling all or none of
the events. The --metric-no-group option places events
outside of groups and may increase the chance of the event
being scheduled - leading to more accuracy. However, as
events may not be scheduled together accuracy for metrics
like instructions per cycle can be lower - as both metrics
may no longer be being measured at the same time.
--metric-no-merge
By default metric events in different weak groups can be
shared if one group contains all the events needed by
another. In such cases one group will be eliminated reducing
event multiplexing and making it so that certain groups of
metrics sum to 100%. A downside to sharing a group is that
the group may require multiplexing and so accuracy for a
small group that need not have multiplexing is lowered. This
option forbids the event merging logic from sharing events
between groups and may be used to increase accuracy in this
case.
--quiet
Don't print output. This is useful with perf stat record
below to only write data to the perf.data file.
