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PERF-RECORD(1) perf Manual PERF-RECORD(1)

NAME

perf-record - Run a command and record its profile into perf.data

SYNOPSIS

perf record [-e <EVENT> | --event=EVENT] [-l] [-a] <command>
perf record [-e <EVENT> | --event=EVENT] [-l] [-a] — <command> [<options>]

DESCRIPTION

This command runs a command and gathers a performance counter profile from it, into perf.data - without displaying anything.

This file can then be inspected later on, using perf report.

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 PMU event like pmu/param1=0x3,param2/ where param1, param2, etc 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,config3=K/ 

where M, N, K are numbers (in decimal, hex, octal format). Acceptable
values for each of ´config´, ´config1´ and ´config2´ are defined by
corresponding entries in /sys/bus/event_sources/devices/<pmu>/format/*
param1 and param2 are defined as formats for the PMU in:
/sys/bus/event_sources/devices/<pmu>/format/*

•a group of events surrounded by a pair of brace ("{event1,event2,...}"). Each event is separated by commas and the group should be quoted to prevent the shell interpretation. You also need to use --group on "perf report" to view group events together.

--filter=<filter>

Event filter.

-a, --all-cpus

System-wide collection from all CPUs.

-p, --pid=

Record events on existing process ID (comma separated list).

-t, --tid=

Record events on existing thread ID (comma separated list). This option also disables inheritance by default. Enable it by adding --inherit.

-u, --uid=

Record events in threads owned by uid. Name or number.

-r, --realtime=

Collect data with this RT SCHED_FIFO priority.

--no-buffering

Collect data without buffering.

-c, --count=

Event period to sample.

-o, --output=

Output file name.

-i, --no-inherit

Child tasks do not inherit counters.

-F, --freq=

Profile at this frequency.

-m, --mmap-pages=

Number of mmap data pages (must be a power of two) or size specification with appended unit character - B/K/M/G. The size is rounded up to have nearest pages power of two value.

--group

Put all events in a single event group. This precedes the --event option and remains only for backward compatibility. See --event.

-g

Enables call-graph (stack chain/backtrace) recording.

--call-graph

Setup and enable call-graph (stack chain/backtrace) recording, implies -g. 

Allows specifying "fp" (frame pointer) or "dwarf"
(DWARF´s CFI - Call Frame Information) or "lbr"
(Hardware Last Branch Record facility) as the method to collect
the information used to show the call graphs.

In some systems, where binaries are build with gcc
--fomit-frame-pointer, using the "fp" method will produce bogus
call graphs, using "dwarf", if available (perf tools linked to
the libunwind library) should be used instead.
Using the "lbr" method doesn´t require any compiler options. It
will produce call graphs from the hardware LBR registers. The
main limition is that it is only available on new Intel
platforms, such as Haswell. It can only get user call chain. It
doesn´t work with branch stack sampling at the same time.

-q, --quiet

Don’t print any message, useful for scripting.

-v, --verbose

Be more verbose (show counter open errors, etc).

-s, --stat

Per thread counts.

-d, --data

Sample addresses.

-T, --timestamp

Sample timestamps. Use it with perf report -D to see the timestamps, for instance.

-n, --no-samples

Don’t sample.

-R, --raw-samples

Collect raw sample records from all opened counters (default for tracepoint counters).

-C, --cpu

Collect samples 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 with inheritance mode on (default), samples are captured only when the thread executes on the designated CPUs. Default is to monitor all CPUs.

-N, --no-buildid-cache

Do not update the buildid cache. This saves some overhead in situations where the information in the perf.data file (which includes buildids) is sufficient.

-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.

-b, --branch-any

Enable taken branch stack sampling. Any type of taken branch may be sampled. This is a shortcut for --branch-filter any. See --branch-filter for more infos.

-j, --branch-filter

Enable taken branch stack sampling. Each sample captures a series of consecutive taken branches. The number of branches captured with each sample depends on the underlying hardware, the type of branches of interest, and the executed code. It is possible to select the types of branches captured by enabling filters. The following filters are defined:

•any: any type of branches

•any_call: any function call or system call

•any_ret: any function return or system call return

•ind_call: any indirect branch

•u: only when the branch target is at the user level

•k: only when the branch target is in the kernel

•hv: only when the target is at the hypervisor level

•in_tx: only when the target is in a hardware transaction

•no_tx: only when the target is not in a hardware transaction

•abort_tx: only when the target is a hardware transaction abort
The option requires at least one branch type among any, any_call, any_ret, ind_call. The privilege levels may be omitted, in which case, the privilege levels of the associated event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege levels are subject to permissions. When sampling on multiple events, branch stack sampling is enabled for all the sampling events. The sampled branch type is the same for all events. The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k Note that this feature may not be available on all processors.

--weight

Enable weightened sampling. An additional weight is recorded per sample and can be displayed with the weight and local_weight sort keys. This currently works for TSX abort events and some memory events in precise mode on modern Intel CPUs.

--transaction

Record transaction flags for transaction related events.

--per-thread

Use per-thread mmaps. By default per-cpu mmaps are created. This option overrides that and uses per-thread mmaps. A side-effect of that is that inheritance is automatically disabled. --per-thread is ignored with a warning if combined with -a or -C options.

-D, --delay=

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.

-I, --intr-regs

Capture machine state (registers) at interrupt, i.e., on counter overflows for each sample. List of captured registers depends on the architecture. This option is off by default.

--running-time

Record running and enabled time for read events (:S)

SEE ALSO

perf-stat(1), perf-list(1)

05/02/2024 perf