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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFIGURATION FILE | SEE ALSO | COLOPHON |
PERF-CONFIG(1) perf Manual PERF-CONFIG(1)
perf-config - Get and set variables in a configuration file.
perf config [<file-option>] [section.name[=value] ...]
or
perf config [<file-option>] -l | --list
You can manage variables in a configuration file with this command.
-l, --list
Show current config variables, name and value, for all sections.
--user
For writing and reading options: write to user $HOME/.perfconfig
file or read it.
--system
For writing and reading options: write to system-wide
$(sysconfdir)/perfconfig or read it.
The perf configuration file contains many variables to change various
aspects of each of its tools, including output, disk usage, etc. The
$HOME/.perfconfig file is used to store a per-user configuration. The
file $(sysconfdir)/perfconfig can be used to store a system-wide
default configuration.
When reading or writing, the values are read from the system and user
configuration files by default, and options --system and --user can
be used to tell the command to read from or write to only that
location.
Syntax
The file consist of sections. A section starts with its name
surrounded by square brackets and continues till the next section
begins. Each variable must be in a section, and have the form name =
value, for example:
[section]
name1 = value1
name2 = value2
Section names are case sensitive and can contain any characters
except newline (double quote " and backslash have to be escaped as \"
and \\, respectively). Section headers can’t span multiple lines.
Example
Given a $HOME/.perfconfig like this:
# # This is the config file, and # a # and ; character indicates a
comment #
[colors]
# Color variables
top = red, default
medium = green, default
normal = lightgray, default
selected = white, lightgray
jump_arrows = blue, default
addr = magenta, default
root = white, blue
[tui]
# Defaults if linked with libslang
report = on
annotate = on
top = on
[buildid]
# Default, disable using /dev/null
dir = ~/.debug
[annotate]
# Defaults
hide_src_code = false
use_offset = true
jump_arrows = true
show_nr_jumps = false
[help]
# Format can be man, info, web or html
format = man
autocorrect = 0
[ui]
show-headers = true
[call-graph]
# fp (framepointer), dwarf
record-mode = fp
print-type = graph
order = caller
sort-key = function
[report]
# Defaults
sort-order = comm,dso,symbol
percent-limit = 0
queue-size = 0
children = true
group = true
You can hide source code of annotate feature setting the config to
false with
% perf config annotate.hide_src_code=true
If you want to add or modify several config items, you can do like
% perf config ui.show-headers=false kmem.default=slab
To modify the sort order of report functionality in user config
file(i.e. ~/.perfconfig), do
% perf config --user report sort-order=srcline
To change colors of selected line to other foreground and background
colors in system config file (i.e. $(sysconf)/perfconfig), do
% perf config --system colors.selected=yellow,green
To query the record mode of call graph, do
% perf config call-graph.record-mode
If you want to know multiple config key/value pairs, you can do like
% perf config report.queue-size call-graph.order report.children
To query the config value of sort order of call graph in user config
file (i.e. ~/.perfconfig), do
% perf config --user call-graph.sort-order
To query the config value of buildid directory in system config file
(i.e. $(sysconf)/perfconfig), do
% perf config --system buildid.dir
Variables
colors.*
The variables for customizing the colors used in the output for
the report, top and annotate in the TUI. They should specify the
foreground and background colors, separated by a comma, for
example:
medium = green, lightgray
If you want to use the color configured for you terminal, just leave it
as 'default', for example:
medium = default, lightgray
Available colors:
red, yellow, green, cyan, gray, black, blue,
white, default, magenta, lightgray
colors.top
top means a overhead percentage which is more than 5%. And values
of this variable specify percentage colors. Basic key values are
foreground-color red and background-color default.
colors.medium
medium means a overhead percentage which has more than 0.5%.
Default values are green and default.
colors.normal
normal means the rest of overhead percentages except top, medium,
selected. Default values are lightgray and default.
colors.selected
This selects the colors for the current entry in a list of
entries from sub-commands (top, report, annotate). Default values
are black and lightgray.
colors.jump_arrows
Colors for jump arrows on assembly code listings such as jns,
jmp, jane, etc. Default values are blue, default.
colors.addr
This selects colors for addresses from annotate. Default values
are magenta, default.
colors.root
Colors for headers in the output of a sub-commands (top, report).
Default values are white, blue.
tui., gtk.
Subcommands that can be configured here are top, report and
annotate. These values are booleans, for example:
[tui]
top = true
will make the TUI be the default for the 'top' subcommand. Those will be
available if the required libs were detected at tool build time.
buildid.*, buildid.dir
Each executable and shared library in modern distributions comes
with a content based identifier that, if available, will be
inserted in a perf.data file header to, at analysis time find
what is needed to do symbol resolution, code annotation, etc.
The recording tools also stores a hard link or copy in a per-user
directory, $HOME/.debug/, of binaries, shared libraries, /proc/kallsyms
and /proc/kcore files to be used at analysis time.
The buildid.dir variable can be used to either change this directory
cache location, or to disable it altogether. If you want to disable it,
set buildid.dir to /dev/null. The default is $HOME/.debug
annotate.*
These options work only for TUI. These are in control of
addresses, jump function, source code in lines of assembly code
from a specific program.
annotate.hide_src_code
If a program which is analyzed has source code, this option lets
annotate print a list of assembly code with the source code. For
example, let’s see a part of a program. There’re four lines. If
this option is true, they can be printed without source code from
a program as below.
│ push %rbp
│ mov %rsp,%rbp
│ sub $0x10,%rsp
│ mov (%rdi),%rdx
But if this option is 'false', source code of the part
can be also printed as below. Default is 'false'.
│ struct rb_node *rb_next(const struct rb_node *node)
│ {
│ push %rbp
│ mov %rsp,%rbp
│ sub $0x10,%rsp
│ struct rb_node *parent;
│
│ if (RB_EMPTY_NODE(node))
│ mov (%rdi),%rdx
│ return n;
annotate.use_offset
Basing on a first address of a loaded function, offset can be
used. Instead of using original addresses of assembly code,
addresses subtracted from a base address can be printed. Let’s
illustrate an example. If a base address is 0XFFFFFFFF81624d50 as
below,
ffffffff81624d50 <load0>
an address on assembly code has a specific absolute address as below
ffffffff816250b8:│ mov 0x8(%r14),%rdi
but if use_offset is 'true', an address subtracted from a base address is printed.
Default is true. This option is only applied to TUI.
368:│ mov 0x8(%r14),%rdi
annotate.jump_arrows
There can be jump instruction among assembly code. Depending on a
boolean value of jump_arrows, arrows can be printed or not which
represent where do the instruction jump into as below.
│ ┌──jmp 1333
│ │ xchg %ax,%ax
│1330:│ mov %r15,%r10
│1333:└─→cmp %r15,%r14
If jump_arrow is 'false', the arrows isn't printed as below.
Default is 'false'.
│ ↓ jmp 1333
│ xchg %ax,%ax
│1330: mov %r15,%r10
│1333: cmp %r15,%r14
annotate.show_linenr
When showing source code if this option is true, line numbers are
printed as below.
│1628 if (type & PERF_SAMPLE_IDENTIFIER) {
│ ↓ jne 508
│1628 data->id = *array;
│1629 array++;
│1630 }
However if this option is 'false', they aren't printed as below.
Default is 'false'.
│ if (type & PERF_SAMPLE_IDENTIFIER) {
│ ↓ jne 508
│ data->id = *array;
│ array++;
│ }
annotate.show_nr_jumps
Let’s see a part of assembly code.
│1382: movb $0x1,-0x270(%rbp)
If use this, the number of branches jumping to that address can be printed as below.
Default is 'false'.
│1 1382: movb $0x1,-0x270(%rbp)
annotate.show_total_period
To compare two records on an instruction base, with this option
provided, display total number of samples that belong to a line
in assembly code. If this option is true, total periods are
printed instead of percent values as below.
302 │ mov %eax,%eax
But if this option is 'false', percent values for overhead are printed i.e.
Default is 'false'.
99.93 │ mov %eax,%eax
hist.*, hist.percentage
This option control the way to calculate overhead of filtered
entries - that means the value of this option is effective only
if there’s a filter (by comm, dso or symbol name). Suppose a
following example:
Overhead Symbols
........ .......
33.33% foo
33.33% bar
33.33% baz
This is an original overhead and we'll filter out the first 'foo'
entry. The value of 'relative' would increase the overhead of 'bar'
and 'baz' to 50.00% for each, while 'absolute' would show their
current overhead (33.33%).
ui.*, ui.show-headers
This option controls display of column headers (like Overhead and
Symbol) in report and top. If this option is false, they are
hidden. This option is only applied to TUI.
call-graph.*
When sub-commands top and report work with -g/—-children there’re
options in control of call-graph.
call-graph.record-mode
The record-mode can be fp (frame pointer), dwarf and lbr. The
value of dwarf is effective only if perf detect needed library
(libunwind or a recent version of libdw). lbr only work for cpus
that support it.
call-graph.dump-size
The size of stack to dump in order to do post-unwinding. Default
is 8192 (byte). When using dwarf into record-mode, the default
size will be used if omitted.
call-graph.print-type
The print-types can be graph (graph absolute), fractal (graph
relative), flat and folded. This option controls a way to show
overhead for each callchain entry. Suppose a following example.
Overhead Symbols
........ .......
40.00% foo
|
---foo
|
|--50.00%--bar
| main
|
--50.00%--baz
main
This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
half and half so 'fractal' shows 50.00% for each
(meaning that it assumes 100% total overhead of 'foo').
The 'graph' uses absolute overhead value of 'foo' as total so each of
'bar' and 'baz' callchain will have 20.00% of overhead.
If 'flat' is used, single column and linear exposure of call chains.
'folded' mean call chains are displayed in a line, separated by semicolons.
call-graph.order
This option controls print order of callchains. The default is
callee which means callee is printed at top and then followed by
its caller and so on. The caller prints it in reverse order.
If this option is not set and report.children or top.children is
set to true (or the equivalent command line option is given),
the default value of this option is changed to 'caller' for the
execution of 'perf report' or 'perf top'. Other commands will
still default to 'callee'.
call-graph.sort-key
The callchains are merged if they contain same information. The
sort-key option determines a way to compare the callchains. A
value of sort-key can be function or address. The default is
function.
call-graph.threshold
When there’re many callchains it’d print tons of lines. So perf
omits small callchains under a certain overhead (threshold) and
this option control the threshold. Default is 0.5 (%). The
overhead is calculated by value depends on call-graph.print-type.
call-graph.print-limit
This is a maximum number of lines of callchain printed for a
single histogram entry. Default is 0 which means no limitation.
report.*, report.sort_order
Allows changing the default sort order from "comm,dso,symbol" to
some other default, for instance "sym,dso" may be more fitting
for kernel developers.
report.percent-limit
This one is mostly the same as call-graph.threshold but works for
histogram entries. Entries having an overhead lower than this
percentage will not be printed. Default is 0. If percent-limit is
10, only entries which have more than 10% of overhead will be
printed.
report.queue-size
This option sets up the maximum allocation size of the internal
event queue for ordering events. Default is 0, meaning no limit.
report.children
Children means functions called from another function. If this
option is true, perf report cumulates callchains of children and
show (accumulated) total overhead as well as Self overhead.
Please refer to the perf report manual. The default is true.
report.group
This option is to show event group information together. Example
output with this turned on, notice that there is one column per
event in the group, ref-cycles and cycles:
# group: {ref-cycles,cycles}
# ========
#
# Samples: 7K of event 'anon group { ref-cycles, cycles }'
# Event count (approx.): 6876107743
#
# Overhead Command Shared Object Symbol
# ................ ....... ................. ...................
#
99.84% 99.76% noploop noploop [.] main
0.07% 0.00% noploop ld-2.15.so [.] strcmp
0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
top.*, top.children
Same as report.children. So if it is enabled, the output of top
command will have Children overhead column as well as Self
overhead column by default. The default is true.
man.*, man.viewer
This option can assign a tool to view manual pages when help
subcommand was invoked. Supported tools are man, woman (with
emacs client) and konqueror. Default is man.
New man viewer tool can be also added using 'man.<tool>.cmd'
or use different path using 'man.<tool>.path' config option.
pager.*, pager.<subcommand>
When the subcommand is run on stdio, determine whether it uses
pager or not based on this value. Default is unspecified.
kmem.*, kmem.default
This option decides which allocator is to be analyzed if neither
--slab nor --page option is used. Default is slab.
record.*, record.build-id
This option can be cache, no-cache or skip. cache is to
post-process data and save/update the binaries into the build-id
cache (in ~/.debug). This is the default. But if this option is
no-cache, it will not update the build-id cache. skip skips
post-processing and does not update the cache.
diff.*, diff.order
This option sets the number of columns to sort the result. The
default is 0, which means sorting by baseline. Setting it to 1
will sort the result by delta (or other compute method selected).
diff.compute
This options sets the method for computing the diff result.
Possible values are delta, delta-abs, ratio and wdiff. Default is
delta.
perf(1)
This page is part of the perf (Performance analysis tools for Linux
(in Linux source tree)) project. Information about the project can
be found at ⟨https://perf.wiki.kernel.org/index.php/Main_Page⟩. If
you have a bug report for this manual page, send it to
linux-kernel@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git⟩ on
2017-07-05. If you discover any rendering problems in this HTML ver‐
sion of the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original man‐
ual page), send a mail to man-pages@man7.org
perf 03/12/2017 PERF-CONFIG(1)