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PERF-REPORT(1) perf Manual PERF-REPORT(1)

NAME

perf-report - Read perf.data (created by perf record) and display the profile

SYNOPSIS

perf report [-i <file> | --input=file]

DESCRIPTION

This command displays the performance counter profile information recorded via perf record.

OPTIONS

-i, --input=

Input file name. (default: perf.data unless stdin is a fifo)

-v, --verbose

Be more verbose. (show symbol address, etc)

-n, --show-nr-samples

Show the number of samples for each symbol

--showcpuutilization

Show sample percentage for different cpu modes.

-T, --threads

Show per-thread event counters

-c, --comms=

Only consider symbols in these comms. CSV that understands file://filename entries. This option will affect the percentage of the overhead column. See --percentage for more info.

--pid=

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

--tid=

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

-d, --dsos=

Only consider symbols in these dsos. CSV that understands file://filename entries. This option will affect the percentage of the overhead column. See --percentage for more info.

-S, --symbols=

Only consider these symbols. CSV that understands file://filename entries. This option will affect the percentage of the overhead column. See --percentage for more info.

--symbol-filter=

Only show symbols that match (partially) with this filter.

-U, --hide-unresolved

Only display entries resolved to a symbol.

-s, --sort=

Sort histogram entries by given key(s) - multiple keys can be specified in CSV format. Following sort keys are available: pid, comm, dso, symbol, parent, cpu, srcline, weight, local_weight. 

Each key has following meaning:

•comm: command (name) of the task which can be read via /proc/<pid>/comm

•pid: command and tid of the task

•dso: name of library or module executed at the time of sample

•symbol: name of function executed at the time of sample

•parent: name of function matched to the parent regex filter. Unmatched entries are displayed as "[other]".

•cpu: cpu number the task ran at the time of sample

•srcline: filename and line number executed at the time of sample. The DWARF debugging info must be provided.

•weight: Event specific weight, e.g. memory latency or transaction abort cost. This is the global weight.

•local_weight: Local weight version of the weight above.

•transaction: Transaction abort flags.

•overhead: Overhead percentage of sample

•overhead_sys: Overhead percentage of sample running in system mode

•overhead_us: Overhead percentage of sample running in user mode

•overhead_guest_sys: Overhead percentage of sample running in system mode on guest machine

•overhead_guest_us: Overhead percentage of sample running in user mode on guest machine

•sample: Number of sample

•period: Raw number of event count of sample 

By default, comm, dso and symbol keys are used.
(i.e. --sort comm,dso,symbol)

If --branch-stack option is used, following sort keys are also
available:
dso_from, dso_to, symbol_from, symbol_to, mispredict.

•dso_from: name of library or module branched from

•dso_to: name of library or module branched to

•symbol_from: name of function branched from

•symbol_to: name of function branched to

•mispredict: "N" for predicted branch, "Y" for mispredicted branch

•in_tx: branch in TSX transaction

•abort: TSX transaction abort.

•cycles: Cycles in basic block 

And default sort keys are changed to comm, dso_from, symbol_from, dso_to
and symbol_to, see ´--branch-stack´.

-F, --fields=

Specify output field - multiple keys can be specified in CSV format. Following fields are available: overhead, overhead_sys, overhead_us, overhead_children, sample and period. Also it can contain any sort key(s). 

By default, every sort keys not specified in -F will be appended
automatically.

If --mem-mode option is used, following sort keys are also available
(incompatible with --branch-stack):
symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline.

•symbol_daddr: name of data symbol being executed on at the time of sample

•dso_daddr: name of library or module containing the data being executed on at the time of sample

•locked: whether the bus was locked at the time of sample

•tlb: type of tlb access for the data at the time of sample

•mem: type of memory access for the data at the time of sample

•snoop: type of snoop (if any) for the data at the time of sample

•dcacheline: the cacheline the data address is on at the time of sample 

And default sort keys are changed to local_weight, mem, sym, dso,
symbol_daddr, dso_daddr, snoop, tlb, locked, see ´--mem-mode´.

-p, --parent=<regex>

A regex filter to identify parent. The parent is a caller of this function and searched through the callchain, thus it requires callchain information recorded. The pattern is in the exteneded regex format and defaults to "^sys_|^do_page_fault", see --sort parent.

-x, --exclude-other

Only display entries with parent-match.

-w, --column-widths=<width[,width...]>

Force each column width to the provided list, for large terminal readability. 0 means no limit (default behavior).

-t, --field-separator=

Use a special separator character and don’t pad with spaces, replacing all occurrences of this separator in symbol names (and other output) with a . character, that thus it’s the only non valid separator.

-D, --dump-raw-trace

Dump raw trace in ASCII.

-g [type,min[,limit],order[,key][,branch]], --call-graph

Display call chains using type, min percent threshold, optional print limit and order. type can be either:

•flat: single column, linear exposure of call chains.

•graph: use a graph tree, displaying absolute overhead rates.

•fractal: like graph, but displays relative rates. Each branch of the tree is considered as a new profiled object. 

order can be either:
- callee: callee based call graph.
- caller: inverted caller based call graph.

key can be:
- function: compare on functions
- address: compare on individual code addresses

branch can be:
- branch: include last branch information in callgraph
when available. Usually more convenient to use --branch-history
for this.

Default: fractal,0.5,callee,function.

--children

Accumulate callchain of children to parent entry so that then can show up in the output. The output will have a new "Children" column and will be sorted on the data. It requires callchains are recorded.

--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. 

Default: 127

-G, --inverted

alias for inverted caller based call graph.

--ignore-callees=<regex>

Ignore callees of the function(s) matching the given regex. This has the effect of collecting the callers of each such function into one place in the call-graph tree.

--pretty=<key>

Pretty printing style. key: normal, raw

--stdio

Use the stdio interface.

--tui

Use the TUI interface, that is integrated with annotate and allows zooming into DSOs or threads, among other features. Use of --tui requires a tty, if one is not present, as when piping to other commands, the stdio interface is used.

--gtk

Use the GTK2 interface.

-k, --vmlinux=<file>

vmlinux pathname

--kallsyms=<file>

kallsyms pathname

-m, --modules

Load module symbols. WARNING: This should only be used with -k and a LIVE kernel.

-f, --force

Don’t complain, do it.

--symfs=<directory>

Look for files with symbols relative to this directory.

-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.

-M, --disassembler-style=

Set disassembler style for objdump.

--source

Interleave source code with assembly code. Enabled by default, disable with --no-source.

--asm-raw

Show raw instruction encoding of assembly instructions.

--show-total-period

Show a column with the sum of periods.

-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.

-b, --branch-stack

Use the addresses of sampled taken branches instead of the instruction address to build the histograms. To generate meaningful output, the perf.data file must have been obtained using perf record -b or perf record --branch-filter xxx where xxx is a branch filter option. perf report is able to auto-detect whether a perf.data file contains branch stacks and it will automatically switch to the branch view mode, unless --no-branch-stack is used.

--branch-history

Add the addresses of sampled taken branches to the callstack. This allows to examine the path the program took to each sample. The data collection must have used -b (or -j) and -g.

--objdump=<path>

Path to objdump binary.

--group

Show event group information together.

--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).

--mem-mode

Use the data addresses of samples in addition to instruction addresses to build the histograms. To generate meaningful output, the perf.data file must have been obtained using perf record -d -W and using a special event -e cpu/mem-loads/ or -e cpu/mem-stores/. See perf mem for simpler access.

--percent-limit

Do not show entries which have an overhead under that percent. (Default: 0).

--percentage

Determine how to display the overhead percentage of filtered entries. Filters can be applied by --comms, --dsos and/or --symbols options and Zoom operations on the TUI (thread, dso, etc). 

"relative" means it´s relative to filtered entries only so that the
sum of shown entries will be always 100%.  "absolute" means it retains
the original value before and after the filter is applied.

--header

Show header information in the perf.data file. This includes various information like hostname, OS and perf version, cpu/mem info, perf command line, event list and so on. Currently only --stdio output supports this feature.

--header-only

Show only perf.data header (forces --stdio).

--full-source-path

Show the full path for source files for srcline output.

SEE ALSO

perf-stat(1), perf-annotate(1)

05/02/2024 perf