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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
-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.
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)
e synthesize error events
d create a debug log
g synthesize a call chain for instructions events
The default is all events i.e. the same as --itrace=ibe
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
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]
|