b21484f1a1
For example, in an application with an expensive function implemented
with deeply nested recursive calls, the default call-graph presentation
is dominated by the different callchains within that function. By
ignoring these callees, we can collect the callchains leading into the
function and compactly identify what to blame for expensive calls.
For example, in this report the callers of garbage_collect() are
scattered across the tree:
$ perf report -d ruby 2>- | grep -m10 ^[^#]*[a-z]
22.03% ruby [.] gc_mark
--- gc_mark
|--59.40%-- mark_keyvalue
| st_foreach
| gc_mark_children
| |--99.75%-- rb_gc_mark
| | rb_vm_mark
| | gc_mark_children
| | gc_marks
| | |--99.00%-- garbage_collect
If we ignore the callees of garbage_collect(), its callers are coalesced:
$ perf report --ignore-callees garbage_collect -d ruby 2>- | grep -m10 ^[^#]*[a-z]
72.92% ruby [.] garbage_collect
--- garbage_collect
vm_xmalloc
|--47.08%-- ruby_xmalloc
| st_insert2
| rb_hash_aset
| |--98.45%-- features_index_add
| | rb_provide_feature
| | rb_require_safe
| | vm_call_method
Signed-off-by: Greg Price <price@mit.edu>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130623031720.GW22203@biohazard-cafe.mit.edu
Link: http://lkml.kernel.org/r/20130708115746.GO22203@biohazard-cafe.mit.edu
Cc: Fengguang Wu <fengguang.wu@intel.com>
[ remove spaces at beginning of line, reported by Fengguang Wu ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
225 lines
6.3 KiB
Plaintext
225 lines
6.3 KiB
Plaintext
perf-report(1)
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==============
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NAME
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----
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perf-report - Read perf.data (created by perf record) and display the profile
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SYNOPSIS
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--------
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[verse]
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'perf report' [-i <file> | --input=file]
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DESCRIPTION
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-----------
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This command displays the performance counter profile information recorded
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via perf record.
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OPTIONS
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-------
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-i::
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--input=::
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Input file name. (default: perf.data unless stdin is a fifo)
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-v::
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--verbose::
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Be more verbose. (show symbol address, etc)
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-d::
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--dsos=::
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Only consider symbols in these dsos. CSV that understands
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file://filename entries.
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-n::
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--show-nr-samples::
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Show the number of samples for each symbol
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--showcpuutilization::
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Show sample percentage for different cpu modes.
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-T::
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--threads::
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Show per-thread event counters
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-c::
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--comms=::
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Only consider symbols in these comms. CSV that understands
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file://filename entries.
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-S::
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--symbols=::
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Only consider these symbols. CSV that understands
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file://filename entries.
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--symbol-filter=::
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Only show symbols that match (partially) with this filter.
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-U::
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--hide-unresolved::
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Only display entries resolved to a symbol.
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-s::
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--sort=::
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Sort histogram entries by given key(s) - multiple keys can be specified
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in CSV format. Following sort keys are available:
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pid, comm, dso, symbol, parent, cpu, srcline, weight, local_weight.
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Each key has following meaning:
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- comm: command (name) of the task which can be read via /proc/<pid>/comm
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- pid: command and tid of the task
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- dso: name of library or module executed at the time of sample
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- symbol: name of function executed at the time of sample
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- parent: name of function matched to the parent regex filter. Unmatched
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entries are displayed as "[other]".
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- cpu: cpu number the task ran at the time of sample
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- srcline: filename and line number executed at the time of sample. The
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DWARF debuggin info must be provided.
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By default, comm, dso and symbol keys are used.
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(i.e. --sort comm,dso,symbol)
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If --branch-stack option is used, following sort keys are also
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available:
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dso_from, dso_to, symbol_from, symbol_to, mispredict.
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- dso_from: name of library or module branched from
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- dso_to: name of library or module branched to
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- symbol_from: name of function branched from
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- symbol_to: name of function branched to
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- mispredict: "N" for predicted branch, "Y" for mispredicted branch
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And default sort keys are changed to comm, dso_from, symbol_from, dso_to
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and symbol_to, see '--branch-stack'.
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-p::
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--parent=<regex>::
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A regex filter to identify parent. The parent is a caller of this
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function and searched through the callchain, thus it requires callchain
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information recorded. The pattern is in the exteneded regex format and
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defaults to "\^sys_|^do_page_fault", see '--sort parent'.
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-x::
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--exclude-other::
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Only display entries with parent-match.
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-w::
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--column-widths=<width[,width...]>::
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Force each column width to the provided list, for large terminal
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readability.
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-t::
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--field-separator=::
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Use a special separator character and don't pad with spaces, replacing
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all occurrences of this separator in symbol names (and other output)
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with a '.' character, that thus it's the only non valid separator.
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-D::
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--dump-raw-trace::
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Dump raw trace in ASCII.
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-g [type,min[,limit],order]::
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--call-graph::
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Display call chains using type, min percent threshold, optional print
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limit and order.
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type can be either:
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- flat: single column, linear exposure of call chains.
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- graph: use a graph tree, displaying absolute overhead rates.
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- fractal: like graph, but displays relative rates. Each branch of
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the tree is considered as a new profiled object. +
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order can be either:
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- callee: callee based call graph.
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- caller: inverted caller based call graph.
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Default: fractal,0.5,callee.
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-G::
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--inverted::
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alias for inverted caller based call graph.
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--ignore-callees=<regex>::
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Ignore callees of the function(s) matching the given regex.
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This has the effect of collecting the callers of each such
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function into one place in the call-graph tree.
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--pretty=<key>::
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Pretty printing style. key: normal, raw
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--stdio:: Use the stdio interface.
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--tui:: Use the TUI interface, that is integrated with annotate and allows
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zooming into DSOs or threads, among other features. Use of --tui
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requires a tty, if one is not present, as when piping to other
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commands, the stdio interface is used.
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--gtk:: Use the GTK2 interface.
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-k::
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--vmlinux=<file>::
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vmlinux pathname
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--kallsyms=<file>::
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kallsyms pathname
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-m::
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--modules::
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Load module symbols. WARNING: This should only be used with -k and
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a LIVE kernel.
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-f::
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--force::
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Don't complain, do it.
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--symfs=<directory>::
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Look for files with symbols relative to this directory.
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-C::
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--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
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be provided as a comma-separated list with no space: 0,1. Ranges of
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CPUs are specified with -: 0-2. Default is to report samples on all
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CPUs.
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-M::
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--disassembler-style=:: Set disassembler style for objdump.
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--source::
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Interleave source code with assembly code. Enabled by default,
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disable with --no-source.
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--asm-raw::
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Show raw instruction encoding of assembly instructions.
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--show-total-period:: Show a column with the sum of periods.
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-I::
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--show-info::
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Display extended information about the perf.data file. This adds
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information which may be very large and thus may clutter the display.
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It currently includes: cpu and numa topology of the host system.
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-b::
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--branch-stack::
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Use the addresses of sampled taken branches instead of the instruction
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address to build the histograms. To generate meaningful output, the
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perf.data file must have been obtained using perf record -b or
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perf record --branch-filter xxx where xxx is a branch filter option.
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perf report is able to auto-detect whether a perf.data file contains
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branch stacks and it will automatically switch to the branch view mode,
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unless --no-branch-stack is used.
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--objdump=<path>::
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Path to objdump binary.
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--group::
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Show event group information together.
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--demangle::
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Demangle symbol names to human readable form. It's enabled by default,
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disable with --no-demangle.
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--percent-limit::
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Do not show entries which have an overhead under that percent.
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(Default: 0).
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SEE ALSO
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--------
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linkperf:perf-stat[1], linkperf:perf-annotate[1]
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