perf tools: Defaults to 'caller' callchain order only if --children is enabled

[deliverable/linux.git] / tools / perf / Documentation / 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, socket, 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
	- socket: processor socket 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.
	- srcfile: file name of the source file of the same. Requires dwarf
	information.
	- 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: graph,0.5,caller

--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.
	Note that when using the --itrace option the synthesized callchain size
	will override this value if the synthesized callchain size is bigger.

	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:

include::itrace.txt[]

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

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

--show-ref-call-graph::
	When multiple events are sampled, it may not be needed to collect
	callgraphs for all of them. The sample sites are usually nearby,
	and it's enough to collect the callgraphs on a reference event.
	So user can use "call-graph=no" event modifier to disable callgraph
	for other events to reduce the overhead.
	However, perf report cannot show callgraphs for the event which
	disable the callgraph.
	This option extends the perf report to show reference callgraphs,
	which collected by reference event, in no callgraph event.

--socket-filter::
	Only report the samples on the processor socket that match with this filter

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

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