xref: /openbmc/linux/tools/perf/Documentation/perf-script.txt (revision 2cf1c348)

perf-script(1)
=============

NAME
----
perf-script - Read perf.data (created by perf record) and display trace output

SYNOPSIS
--------
[verse]
'perf script' [<options>]
'perf script' [<options>] record <script> [<record-options>] <command>
'perf script' [<options>] report <script> [script-args]
'perf script' [<options>] <script> <required-script-args> [<record-options>] <command>
'perf script' [<options>] <top-script> [script-args]

DESCRIPTION
-----------
This command reads the input file and displays the trace recorded.

There are several variants of perf script:

  'perf script' to see a detailed trace of the workload that was
  recorded.

  You can also run a set of pre-canned scripts that aggregate and
  summarize the raw trace data in various ways (the list of scripts is
  available via 'perf script -l').  The following variants allow you to
  record and run those scripts:

  'perf script record <script> <command>' to record the events required
  for 'perf script report'.  <script> is the name displayed in the
  output of 'perf script --list' i.e. the actual script name minus any
  language extension.  If <command> is not specified, the events are
  recorded using the -a (system-wide) 'perf record' option.

  'perf script report <script> [args]' to run and display the results
  of <script>.  <script> is the name displayed in the output of 'perf
  script --list' i.e. the actual script name minus any language
  extension.  The perf.data output from a previous run of 'perf script
  record <script>' is used and should be present for this command to
  succeed.  [args] refers to the (mainly optional) args expected by
  the script.

  'perf script <script> <required-script-args> <command>' to both
  record the events required for <script> and to run the <script>
  using 'live-mode' i.e. without writing anything to disk.  <script>
  is the name displayed in the output of 'perf script --list' i.e. the
  actual script name minus any language extension.  If <command> is
  not specified, the events are recorded using the -a (system-wide)
  'perf record' option.  If <script> has any required args, they
  should be specified before <command>.  This mode doesn't allow for
  optional script args to be specified; if optional script args are
  desired, they can be specified using separate 'perf script record'
  and 'perf script report' commands, with the stdout of the record step
  piped to the stdin of the report script, using the '-o -' and '-i -'
  options of the corresponding commands.

  'perf script <top-script>' to both record the events required for
  <top-script> and to run the <top-script> using 'live-mode'
  i.e. without writing anything to disk.  <top-script> is the name
  displayed in the output of 'perf script --list' i.e. the actual
  script name minus any language extension; a <top-script> is defined
  as any script name ending with the string 'top'.

  [<record-options>] can be passed to the record steps of 'perf script
  record' and 'live-mode' variants; this isn't possible however for
  <top-script> 'live-mode' or 'perf script report' variants.

  See the 'SEE ALSO' section for links to language-specific
  information on how to write and run your own trace scripts.

OPTIONS
-------
<command>...::
	Any command you can specify in a shell.

-D::
--dump-raw-trace=::
        Display verbose dump of the trace data.

-L::
--Latency=::
        Show latency attributes (irqs/preemption disabled, etc).

-l::
--list=::
        Display a list of available trace scripts.

-s ['lang']::
--script=::
        Process trace data with the given script ([lang]:script[.ext]).
	If the string 'lang' is specified in place of a script name, a
        list of supported languages will be displayed instead.

-g::
--gen-script=::
        Generate perf-script.[ext] starter script for given language,
        using current perf.data.

--dlfilter=<file>::
	Filter sample events using the given shared object file.
	Refer linkperf:perf-dlfilter[1]

--dlarg=<arg>::
	Pass 'arg' as an argument to the dlfilter. --dlarg may be repeated
	to add more arguments.

--list-dlfilters::
        Display a list of available dlfilters. Use with option -v (must come
        before option --list-dlfilters) to show long descriptions.

-a::
        Force system-wide collection.  Scripts run without a <command>
        normally use -a by default, while scripts run with a <command>
        normally don't - this option allows the latter to be run in
        system-wide mode.

-i::
--input=::
        Input file name. (default: perf.data unless stdin is a fifo)

-d::
--debug-mode::
        Do various checks like samples ordering and lost events.

-F::
--fields::
        Comma separated list of fields to print. Options are:
        comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr, symoff,
        srcline, period, iregs, uregs, brstack, brstacksym, flags, bpf-output,
        brstackinsn, brstackoff, callindent, insn, insnlen, synth, phys_addr,
        metric, misc, srccode, ipc, data_page_size, code_page_size, ins_lat.
        Field list can be prepended with the type, trace, sw or hw,
        to indicate to which event type the field list applies.
        e.g., -F sw:comm,tid,time,ip,sym  and -F trace:time,cpu,trace

		perf script -F <fields>

	is equivalent to:

		perf script -F trace:<fields> -F sw:<fields> -F hw:<fields>

	i.e., the specified fields apply to all event types if the type string
	is not given.

	In addition to overriding fields, it is also possible to add or remove
	fields from the defaults. For example

		-F -cpu,+insn

	removes the cpu field and adds the insn field. Adding/removing fields
	cannot be mixed with normal overriding.

	The arguments are processed in the order received. A later usage can
	reset a prior request. e.g.:

		-F trace: -F comm,tid,time,ip,sym

	The first -F suppresses trace events (field list is ""), but then the
	second invocation sets the fields to comm,tid,time,ip,sym. In this case a
	warning is given to the user:

		"Overriding previous field request for all events."

	Alternatively, consider the order:

		-F comm,tid,time,ip,sym -F trace:

	The first -F sets the fields for all events and the second -F
	suppresses trace events. The user is given a warning message about
	the override, and the result of the above is that only S/W and H/W
	events are displayed with the given fields.

	It's possible tp add/remove fields only for specific event type:

		-Fsw:-cpu,-period

	removes cpu and period from software events.

	For the 'wildcard' option if a user selected field is invalid for an
	event type, a message is displayed to the user that the option is
	ignored for that type. For example:

		$ perf script -F comm,tid,trace
		'trace' not valid for hardware events. Ignoring.
		'trace' not valid for software events. Ignoring.

	Alternatively, if the type is given an invalid field is specified it
	is an error. For example:

        perf script -v -F sw:comm,tid,trace
        'trace' not valid for software events.

	At this point usage is displayed, and perf-script exits.

	The flags field is synthesized and may have a value when Instruction
	Trace decoding. The flags are "bcrosyiABExgh" which stand for branch,
	call, return, conditional, system, asynchronous, interrupt,
	transaction abort, trace begin, trace end, in transaction, VM-Entry, and VM-Exit
	respectively. Known combinations of flags are printed more nicely e.g.
	"call" for "bc", "return" for "br", "jcc" for "bo", "jmp" for "b",
	"int" for "bci", "iret" for "bri", "syscall" for "bcs", "sysret" for "brs",
	"async" for "by", "hw int" for "bcyi", "tx abrt" for "bA", "tr strt" for "bB",
	"tr end" for "bE", "vmentry" for "bcg", "vmexit" for "bch".
	However the "x" flag will be displayed separately in those
	cases e.g. "jcc     (x)" for a condition branch within a transaction.

	The callindent field is synthesized and may have a value when
	Instruction Trace decoding. For calls and returns, it will display the
	name of the symbol indented with spaces to reflect the stack depth.

	When doing instruction trace decoding insn and insnlen give the
	instruction bytes and the instruction length of the current
	instruction.

	The synth field is used by synthesized events which may be created when
	Instruction Trace decoding.

	The ipc (instructions per cycle) field is synthesized and may have a value when
	Instruction Trace decoding.

	Finally, a user may not set fields to none for all event types.
	i.e., -F "" is not allowed.

	The brstack output includes branch related information with raw addresses using the
	/v/v/v/v/cycles syntax in the following order:
	FROM: branch source instruction
	TO  : branch target instruction
        M/P/-: M=branch target mispredicted or branch direction was mispredicted, P=target predicted or direction predicted, -=not supported
	X/- : X=branch inside a transactional region, -=not in transaction region or not supported
	A/- : A=TSX abort entry, -=not aborted region or not supported
	cycles

	The brstacksym is identical to brstack, except that the FROM and TO addresses are printed in a symbolic form if possible.

	When brstackinsn is specified the full assembler sequences of branch sequences for each sample
	is printed. This is the full execution path leading to the sample. This is only supported when the
	sample was recorded with perf record -b or -j any.

	The brstackoff field will print an offset into a specific dso/binary.

	With the metric option perf script can compute metrics for
	sampling periods, similar to perf stat. This requires
	specifying a group with multiple events defining metrics with the :S option
	for perf record. perf will sample on the first event, and
	print computed metrics for all the events in the group. Please note
	that the metric computed is averaged over the whole sampling
	period (since the last sample), not just for the sample point.

	For sample events it's possible to display misc field with -F +misc option,
	following letters are displayed for each bit:

	  PERF_RECORD_MISC_KERNEL               K
	  PERF_RECORD_MISC_USER                 U
	  PERF_RECORD_MISC_HYPERVISOR           H
	  PERF_RECORD_MISC_GUEST_KERNEL         G
	  PERF_RECORD_MISC_GUEST_USER           g
	  PERF_RECORD_MISC_MMAP_DATA*           M
	  PERF_RECORD_MISC_COMM_EXEC            E
	  PERF_RECORD_MISC_SWITCH_OUT           S
	  PERF_RECORD_MISC_SWITCH_OUT_PREEMPT   Sp

	  $ perf script -F +misc ...
	   sched-messaging  1414 K     28690.636582:       4590 cycles ...
	   sched-messaging  1407 U     28690.636600:     325620 cycles ...
	   sched-messaging  1414 K     28690.636608:      19473 cycles ...
	  misc field ___________/

-k::
--vmlinux=<file>::
        vmlinux pathname

--kallsyms=<file>::
        kallsyms pathname

--symfs=<directory>::
        Look for files with symbols relative to this directory.

-G::
--hide-call-graph::
        When printing symbols do not display call chain.

--stop-bt::
        Stop display of callgraph at these symbols

-C::
--cpu:: Only report samples for 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. Default is to report samples on all
	CPUs.

-c::
--comms=::
	Only display events for these comms. CSV that understands
	file://filename entries.

--pid=::
	Only show events for given process ID (comma separated list).

--tid=::
	Only show events for given thread ID (comma separated list).

-I::
--show-info::
	Display extended information about the perf.data file. This adds
	information which may be very large and thus may clutter the display.
	It currently includes: cpu and numa topology of the host system.
	It can only be used with the perf script report mode.

--show-kernel-path::
	Try to resolve the path of [kernel.kallsyms]

--show-task-events
	Display task related events (e.g. FORK, COMM, EXIT).

--show-mmap-events
	Display mmap related events (e.g. MMAP, MMAP2).

--show-namespace-events
	Display namespace events i.e. events of type PERF_RECORD_NAMESPACES.

--show-switch-events
	Display context switch events i.e. events of type PERF_RECORD_SWITCH or
	PERF_RECORD_SWITCH_CPU_WIDE.

--show-lost-events
	Display lost events i.e. events of type PERF_RECORD_LOST.

--show-round-events
	Display finished round events i.e. events of type PERF_RECORD_FINISHED_ROUND.

--show-bpf-events
	Display bpf events i.e. events of type PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT.

--show-cgroup-events
	Display cgroup events i.e. events of type PERF_RECORD_CGROUP.

--show-text-poke-events
	Display text poke events i.e. events of type PERF_RECORD_TEXT_POKE and
	PERF_RECORD_KSYMBOL.

--demangle::
	Demangle symbol names to human readable form. It's enabled by default,
	disable with --no-demangle.

--demangle-kernel::
	Demangle kernel symbol names to human readable form (for C++ kernels).

--header
	Show perf.data header.

--header-only
	Show only perf.data header.

--itrace::
	Options for decoding instruction tracing data. The options are:

include::itrace.txt[]

	To disable decoding entirely, use --no-itrace.

--full-source-path::
	Show the full path for source files for srcline output.

--max-stack::
        Set the stack depth limit when parsing the callchain, anything
        beyond the specified depth will be ignored. This is a trade-off
        between information loss and faster processing especially for
        workloads that can have a very long callchain stack.
        Note that when using the --itrace option the synthesized callchain size
        will override this value if the synthesized callchain size is bigger.

        Default: 127

--ns::
	Use 9 decimal places when displaying time (i.e. show the nanoseconds)

-f::
--force::
	Don't do ownership validation.

--time::
	Only analyze samples within given time window: <start>,<stop>. Times
	have the format seconds.nanoseconds. If start is not given (i.e. time
	string is ',x.y') then analysis starts at the beginning of the file. If
	stop time is not given (i.e. time string is 'x.y,') then analysis goes
	to end of file. Multiple ranges can be separated by spaces, which
	requires the argument to be quoted e.g. --time "1234.567,1234.789 1235,"

	Also support time percent with multiple time ranges. Time string is
	'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.

	For example:
	Select the second 10% time slice:
	perf script --time 10%/2

	Select from 0% to 10% time slice:
	perf script --time 0%-10%

	Select the first and second 10% time slices:
	perf script --time 10%/1,10%/2

	Select from 0% to 10% and 30% to 40% slices:
	perf script --time 0%-10%,30%-40%

--max-blocks::
	Set the maximum number of program blocks to print with brstackinsn for
	each sample.

--reltime::
	Print time stamps relative to trace start.

--deltatime::
	Print time stamps relative to previous event.

--per-event-dump::
	Create per event files with a "perf.data.EVENT.dump" name instead of
        printing to stdout, useful, for instance, for generating flamegraphs.

--inline::
	If a callgraph address belongs to an inlined function, the inline stack
	will be printed. Each entry has function name and file/line. Enabled by
	default, disable with --no-inline.

--insn-trace::
	Show instruction stream for intel_pt traces. Combine with --xed to
	show disassembly.

--xed::
	Run xed disassembler on output. Requires installing the xed disassembler.

-S::
--symbols=symbol[,symbol...]::
	Only consider the listed symbols. Symbols are typically a name
	but they may also be hexadecimal address.

	The hexadecimal address may be the start address of a symbol or
	any other address to filter the trace records

	For example, to select the symbol noploop or the address 0x4007a0:
	perf script --symbols=noploop,0x4007a0

	Support filtering trace records by symbol name, start address of
	symbol, any hexadecimal address and address range.

	The comparison order is:

	1. symbol name comparison
	2. symbol start address comparison.
	3. any hexadecimal address comparison.
	4. address range comparison (see --addr-range).

--addr-range::
       Use with -S or --symbols to list traced records within address range.

       For example, to list the traced records within the address range
       [0x4007a0, 0x0x4007a9]:
       perf script -S 0x4007a0 --addr-range 10

--dsos=::
	Only consider symbols in these DSOs.

--call-trace::
	Show call stream for intel_pt traces. The CPUs are interleaved, but
	can be filtered with -C.

--call-ret-trace::
	Show call and return stream for intel_pt traces.

--graph-function::
	For itrace only show specified functions and their callees for
	itrace. Multiple functions can be separated by comma.

--switch-on EVENT_NAME::
	Only consider events after this event is found.

--switch-off EVENT_NAME::
	Stop considering events after this event is found.

--show-on-off-events::
	Show the --switch-on/off events too.

--stitch-lbr::
	Show callgraph with stitched LBRs, which may have more complete
	callgraph. The perf.data file must have been obtained using
	perf record --call-graph lbr.
	Disabled by default. In common cases with call stack overflows,
	it can recreate better call stacks than the default lbr call stack
	output. But this approach is not full proof. There can be cases
	where it creates incorrect call stacks from incorrect matches.
	The known limitations include exception handing such as
	setjmp/longjmp will have calls/returns not match.

SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-script-perl[1],
linkperf:perf-script-python[1], linkperf:perf-intel-pt[1],
linkperf:perf-dlfilter[1]