perf-report.txt

perf-report(1)
==============

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

SYNOPSIS
--------
[verse]
'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.  The input data file should be recorded
	with -s option.
-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.
	See the `overhead calculation' section for more details.

--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).

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

		i	synthesize instructions events
		b	synthesize branches events
		c	synthesize branches events (calls only)
		r	synthesize branches events (returns only)
		x	synthesize transactions events
		e	synthesize error events
		d	create a debug log
		g	synthesize a call chain (use with i or x)

	The default is all events i.e. the same as --itrace=ibxe

	In addition, the period (default 100000) 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.

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


include::callchain-overhead-calculation.txt[]

SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-annotate[1]