perf-script(1) — Linux manual page


PERF-SCRIPT(1)                 perf Manual                PERF-SCRIPT(1)

NAME         top

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

SYNOPSIS         top

       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         top

       This command reads the input file and displays the trace

       There are several variants of perf script:

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

           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 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         top

           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

           Filter sample events using the given shared object file.
           Refer perf-dlfilter(1)

           Pass arg as an argument to the dlfilter. --dlarg may be
           repeated to add more arguments.

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

           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: 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. 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:


               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

               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

               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 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 pathname

           Look for files with symbols relative to this directory.

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

           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.

           Only show events for given process ID (comma separated list).

           Only show events for given thread ID (comma separated list).

       -I, --show-info
           Display extended information about the 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.

           Try to resolve the path of [kernel.kallsyms]

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

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

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

       --show-switch-events Display context switch events i.e. events of

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

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

       --show-bpf-events Display bpf events i.e. events of type

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

       --show-text-poke-events Display text poke events i.e. events of

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

           Demangle kernel symbol names to human readable form (for C++

       --header Show header.

       --header-only Show only header.

           Options for decoding instruction tracing data. The options

               i       synthesize instructions events
               b       synthesize branches events (branch misses for Arm SPE)
               c       synthesize branches events (calls only)
               r       synthesize branches events (returns only)
               x       synthesize transactions events
               w       synthesize ptwrite events
               p       synthesize power events (incl. PSB events for Intel PT)
               o       synthesize other events recorded due to the use
                       of aux-output (refer to perf record)
               e       synthesize error events
               d       create a debug log
               f       synthesize first level cache events
               m       synthesize last level cache events
               M       synthesize memory events
               t       synthesize TLB events
               a       synthesize remote access events
               g       synthesize a call chain (use with i or x)
               G       synthesize a call chain on existing event records
               l       synthesize last branch entries (use with i or x)
               L       synthesize last branch entries on existing event records
               s       skip initial number of events
               q       quicker (less detailed) decoding
               Z       prefer to ignore timestamps (so-called "timeless" decoding)

               The default is all events i.e. the same as --itrace=ibxwpe,
               except for perf script where it is --itrace=ce

               In addition, the period (default 100000, except for perf script where it is 1)
               for instructions events can be specified in units of:

               i       instructions
               t       ticks
               ms      milliseconds
               us      microseconds
               ns      nanoseconds (default)

               Also the call chain size (default 16, max. 1024) for instructions or
               transactions events can be specified.

               Also the number of last branch entries (default 64, max. 1024) for
               instructions or transactions events can be specified.

               Similar to options g and l, size may also be specified for options G and L.
               On x86, note that G and L work poorly when data has been recorded with
               large PEBS. Refer linkperf:perf-intel-pt[1] man page for details.

               It is also possible to skip events generated (instructions, branches, transactions,
               ptwrite, power) at the beginning. This is useful to ignore initialization code.


               skips the first million instructions.

               The 'e' option may be followed by flags which affect what errors will or
               will not be reported. Each flag must be preceded by either '+' or '-'.
               The flags are:
                       o       overflow
                       l       trace data lost

               If supported, the 'd' option may be followed by flags which affect what
               debug messages will or will not be logged. Each flag must be preceded
               by either '+' or '-'. The flags are:
                       a       all perf events

               If supported, the 'q' option may be repeated to increase the effect.

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

           Show the full path for source files for srcline output.

           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

           Use 9 decimal places when displaying time (i.e. show the

       -f, --force
           Don’t do ownership validation.

           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%

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

           Print time stamps relative to trace start.

           Print time stamps relative to previous event.

           Create per event files with a "" name
           instead of printing to stdout, useful, for instance, for
           generating flamegraphs.

           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.

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

           Run xed disassembler on output. Requires installing the xed

       -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).

           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

           Only consider symbols in these DSOs.

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

           Show call and return stream for intel_pt traces.

           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 the --switch-on/off events too.

           Show callgraph with stitched LBRs, which may have more
           complete callgraph. The 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         top

       perf-record(1), perf-script-perl(1), perf-script-python(1),
       perf-intel-pt(1), perf-dlfilter(1)

COLOPHON         top

       This page is part of the perf (Performance analysis tools for
       Linux (in Linux source tree)) project.  Information about the
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       bug report for this manual page, send it to  This page was obtained from the
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perf                           2021-07-01                 PERF-SCRIPT(1)

Pages that refer to this page: perf(1)perf-dlfilter(1)perf-intel-pt(1)perf-script-perl(1)perf-script-python(1)perf-trace(1)