6 perf-config - Get and set variables in a configuration file.
11 'perf config' [<file-option>] [section.name[=value] ...]
13 'perf config' [<file-option>] -l | --list
17 You can manage variables in a configuration file with this command.
24 Show current config variables, name and value, for all sections.
27 For writing and reading options: write to user
28 '$HOME/.perfconfig' file or read it.
31 For writing and reading options: write to system-wide
32 '$(sysconfdir)/perfconfig' or read it.
37 The perf configuration file contains many variables to change various
38 aspects of each of its tools, including output, disk usage, etc.
39 The '$HOME/.perfconfig' file is used to store a per-user configuration.
40 The file '$(sysconfdir)/perfconfig' can be used to
41 store a system-wide default configuration.
43 One an disable reading config files by setting the PERF_CONFIG environment
44 variable to /dev/null, or provide an alternate config file by setting that
47 When reading or writing, the values are read from the system and user
48 configuration files by default, and options '--system' and '--user'
49 can be used to tell the command to read from or write to only that location.
54 The file consist of sections. A section starts with its name
55 surrounded by square brackets and continues till the next section
56 begins. Each variable must be in a section, and have the form
57 'name = value', for example:
63 Section names are case sensitive and can contain any characters except
64 newline (double quote `"` and backslash have to be escaped as `\"` and `\\`,
65 respectively). Section headers can't span multiple lines.
70 Given a $HOME/.perfconfig like this:
73 # This is the config file, and
74 # a '#' and ';' character indicates a comment
80 medium = green, default
81 normal = lightgray, default
82 selected = white, lightgray
83 jump_arrows = blue, default
84 addr = magenta, default
88 # Defaults if linked with libslang
94 # Default, disable using /dev/null
102 show_nr_jumps = false
105 # Format can be man, info, web or html
113 # fp (framepointer), dwarf
121 sort_order = comm,dso,symbol
129 You can hide source code of annotate feature setting the config to false with
131 % perf config annotate.hide_src_code=true
133 If you want to add or modify several config items, you can do like
135 % perf config ui.show-headers=false kmem.default=slab
137 To modify the sort order of report functionality in user config file(i.e. `~/.perfconfig`), do
139 % perf config --user report.sort-order=srcline
141 To change colors of selected line to other foreground and background colors
142 in system config file (i.e. `$(sysconf)/perfconfig`), do
144 % perf config --system colors.selected=yellow,green
146 To query the record mode of call graph, do
148 % perf config call-graph.record-mode
150 If you want to know multiple config key/value pairs, you can do like
152 % perf config report.queue-size call-graph.order report.children
154 To query the config value of sort order of call graph in user config file (i.e. `~/.perfconfig`), do
156 % perf config --user call-graph.sort-order
158 To query the config value of buildid directory in system config file (i.e. `$(sysconf)/perfconfig`), do
160 % perf config --system buildid.dir
166 The variables for customizing the colors used in the output for the
167 'report', 'top' and 'annotate' in the TUI. They should specify the
168 foreground and background colors, separated by a comma, for example:
170 medium = green, lightgray
172 If you want to use the color configured for you terminal, just leave it
173 as 'default', for example:
175 medium = default, lightgray
178 red, yellow, green, cyan, gray, black, blue,
179 white, default, magenta, lightgray
182 'top' means a overhead percentage which is more than 5%.
183 And values of this variable specify percentage colors.
184 Basic key values are foreground-color 'red' and
185 background-color 'default'.
187 'medium' means a overhead percentage which has more than 0.5%.
188 Default values are 'green' and 'default'.
190 'normal' means the rest of overhead percentages
191 except 'top', 'medium', 'selected'.
192 Default values are 'lightgray' and 'default'.
194 This selects the colors for the current entry in a list of entries
195 from sub-commands (top, report, annotate).
196 Default values are 'black' and 'lightgray'.
198 Colors for jump arrows on assembly code listings
199 such as 'jns', 'jmp', 'jane', etc.
200 Default values are 'blue', 'default'.
202 This selects colors for addresses from 'annotate'.
203 Default values are 'magenta', 'default'.
205 Colors for headers in the output of a sub-commands (top, report).
206 Default values are 'white', 'blue'.
209 core.proc-map-timeout::
210 Sets a timeout (in milliseconds) for parsing /proc/<pid>/maps files.
211 Can be overridden by the --proc-map-timeout option on supported
212 subcommands. The default timeout is 500ms.
215 Subcommands that can be configured here are 'top', 'report' and 'annotate'.
216 These values are booleans, for example:
221 will make the TUI be the default for the 'top' subcommand. Those will be
222 available if the required libs were detected at tool build time.
226 Each executable and shared library in modern distributions comes with a
227 content based identifier that, if available, will be inserted in a
228 'perf.data' file header to, at analysis time find what is needed to do
229 symbol resolution, code annotation, etc.
231 The recording tools also stores a hard link or copy in a per-user
232 directory, $HOME/.debug/, of binaries, shared libraries, /proc/kallsyms
233 and /proc/kcore files to be used at analysis time.
235 The buildid.dir variable can be used to either change this directory
236 cache location, or to disable it altogether. If you want to disable it,
237 set buildid.dir to /dev/null. The default is $HOME/.debug
240 buildid-cache.debuginfod=URLs
241 Specify debuginfod URLs to be used when retrieving perf.data binaries,
242 it follows the same syntax as the DEBUGINFOD_URLS variable, like:
244 buildid-cache.debuginfod=http://192.168.122.174:8002
247 These are in control of addresses, jump function, source code
248 in lines of assembly code from a specific program.
251 addr2line binary to use for file names and line numbers.
254 objdump binary to use for disassembly and annotations.
256 annotate.disassembler_style::
257 Use this to change the default disassembler style to some other value
258 supported by binutils, such as "intel", see the '-M' option help in the
261 annotate.hide_src_code::
262 If a program which is analyzed has source code,
263 this option lets 'annotate' print a list of assembly code with the source code.
264 For example, let's see a part of a program. There're four lines.
265 If this option is 'true', they can be printed
266 without source code from a program as below.
273 But if this option is 'false', source code of the part
274 can be also printed as below. Default is 'false'.
276 │ struct rb_node *rb_next(const struct rb_node *node)
281 │ struct rb_node *parent;
283 │ if (RB_EMPTY_NODE(node))
287 This option works with tui, stdio2 browsers.
289 annotate.use_offset::
290 Basing on a first address of a loaded function, offset can be used.
291 Instead of using original addresses of assembly code,
292 addresses subtracted from a base address can be printed.
293 Let's illustrate an example.
294 If a base address is 0XFFFFFFFF81624d50 as below,
296 ffffffff81624d50 <load0>
298 an address on assembly code has a specific absolute address as below
300 ffffffff816250b8:│ mov 0x8(%r14),%rdi
302 but if use_offset is 'true', an address subtracted from a base address is printed.
303 Default is true. This option is only applied to TUI.
305 368:│ mov 0x8(%r14),%rdi
307 This option works with tui, stdio2 browsers.
309 annotate.jump_arrows::
310 There can be jump instruction among assembly code.
311 Depending on a boolean value of jump_arrows,
312 arrows can be printed or not which represent
313 where do the instruction jump into as below.
315 │ ┌──jmp 1333
317 │1330:│ mov %r15,%r10
318 │1333:└─→cmp %r15,%r14
320 If jump_arrow is 'false', the arrows isn't printed as below.
325 │1330: mov %r15,%r10
326 │1333: cmp %r15,%r14
328 This option works with tui browser.
330 annotate.show_linenr::
331 When showing source code if this option is 'true',
332 line numbers are printed as below.
334 │1628 if (type & PERF_SAMPLE_IDENTIFIER) {
336 │1628 data->id = *array;
340 However if this option is 'false', they aren't printed as below.
343 │ if (type & PERF_SAMPLE_IDENTIFIER) {
345 │ data->id = *array;
349 This option works with tui, stdio2 browsers.
351 annotate.show_nr_jumps::
352 Let's see a part of assembly code.
354 │1382: movb $0x1,-0x270(%rbp)
356 If use this, the number of branches jumping to that address can be printed as below.
359 │1 1382: movb $0x1,-0x270(%rbp)
361 This option works with tui, stdio2 browsers.
363 annotate.show_total_period::
364 To compare two records on an instruction base, with this option
365 provided, display total number of samples that belong to a line
366 in assembly code. If this option is 'true', total periods are printed
367 instead of percent values as below.
369 302 │ mov %eax,%eax
371 But if this option is 'false', percent values for overhead are printed i.e.
374 99.93 │ mov %eax,%eax
376 This option works with tui, stdio2, stdio browsers.
378 annotate.show_nr_samples::
379 By default perf annotate shows percentage of samples. This option
380 can be used to print absolute number of samples. Ex, when set as
384 74.03 │ mov %fs:0x28,%rax
389 6 │ mov %fs:0x28,%rax
391 This option works with tui, stdio2, stdio browsers.
393 annotate.offset_level::
394 Default is '1', meaning just jump targets will have offsets show right beside
395 the instruction. When set to '2' 'call' instructions will also have its offsets
396 shown, 3 or higher will show offsets for all instructions.
398 This option works with tui, stdio2 browsers.
401 Demangle symbol names to human readable form. Default is 'true'.
403 annotate.demangle_kernel::
404 Demangle kernel symbol names to human readable form. Default is 'true'.
408 This option control the way to calculate overhead of filtered entries -
409 that means the value of this option is effective only if there's a
410 filter (by comm, dso or symbol name). Suppose a following example:
418 This is an original overhead and we'll filter out the first 'foo'
419 entry. The value of 'relative' would increase the overhead of 'bar'
420 and 'baz' to 50.00% for each, while 'absolute' would show their
421 current overhead (33.33%).
425 This option controls display of column headers (like 'Overhead' and 'Symbol')
426 in 'report' and 'top'. If this option is false, they are hidden.
427 This option is only applied to TUI.
430 The following controls the handling of call-graphs (obtained via the
431 -g/--call-graph options).
433 call-graph.record-mode::
434 The mode for user space can be 'fp' (frame pointer), 'dwarf'
435 and 'lbr'. The value 'dwarf' is effective only if libunwind
436 (or a recent version of libdw) is present on the system;
437 the value 'lbr' only works for certain cpus. The method for
438 kernel space is controlled not by this option but by the
439 kernel config (CONFIG_UNWINDER_*).
441 call-graph.dump-size::
442 The size of stack to dump in order to do post-unwinding. Default is 8192 (byte).
443 When using dwarf into record-mode, the default size will be used if omitted.
445 call-graph.print-type::
446 The print-types can be graph (graph absolute), fractal (graph relative),
447 flat and folded. This option controls a way to show overhead for each callchain
448 entry. Suppose a following example.
462 This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
463 half and half so 'fractal' shows 50.00% for each
464 (meaning that it assumes 100% total overhead of 'foo').
466 The 'graph' uses absolute overhead value of 'foo' as total so each of
467 'bar' and 'baz' callchain will have 20.00% of overhead.
468 If 'flat' is used, single column and linear exposure of call chains.
469 'folded' mean call chains are displayed in a line, separated by semicolons.
472 This option controls print order of callchains. The default is
473 'callee' which means callee is printed at top and then followed by its
474 caller and so on. The 'caller' prints it in reverse order.
476 If this option is not set and report.children or top.children is
477 set to true (or the equivalent command line option is given),
478 the default value of this option is changed to 'caller' for the
479 execution of 'perf report' or 'perf top'. Other commands will
480 still default to 'callee'.
482 call-graph.sort-key::
483 The callchains are merged if they contain same information.
484 The sort-key option determines a way to compare the callchains.
485 A value of 'sort-key' can be 'function' or 'address'.
486 The default is 'function'.
488 call-graph.threshold::
489 When there're many callchains it'd print tons of lines. So perf omits
490 small callchains under a certain overhead (threshold) and this option
491 control the threshold. Default is 0.5 (%). The overhead is calculated
492 by value depends on call-graph.print-type.
494 call-graph.print-limit::
495 This is a maximum number of lines of callchain printed for a single
496 histogram entry. Default is 0 which means no limitation.
500 Allows changing the default sort order from "comm,dso,symbol" to
501 some other default, for instance "sym,dso" may be more fitting for
503 report.percent-limit::
504 This one is mostly the same as call-graph.threshold but works for
505 histogram entries. Entries having an overhead lower than this
506 percentage will not be printed. Default is '0'. If percent-limit
507 is '10', only entries which have more than 10% of overhead will be
511 This option sets up the maximum allocation size of the internal
512 event queue for ordering events. Default is 0, meaning no limit.
515 'Children' means functions called from another function.
516 If this option is true, 'perf report' cumulates callchains of children
517 and show (accumulated) total overhead as well as 'Self' overhead.
518 Please refer to the 'perf report' manual. The default is 'true'.
521 This option is to show event group information together.
522 Example output with this turned on, notice that there is one column
523 per event in the group, ref-cycles and cycles:
525 # group: {ref-cycles,cycles}
528 # Samples: 7K of event 'anon group { ref-cycles, cycles }'
529 # Event count (approx.): 6876107743
531 # Overhead Command Shared Object Symbol
532 # ................ ....... ................. ...................
534 99.84% 99.76% noploop noploop [.] main
535 0.07% 0.00% noploop ld-2.15.so [.] strcmp
536 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
539 This option can change default stat behavior with empty results.
540 If it's set true, 'perf report --stat' will not show 0 stats.
544 Same as 'report.children'. So if it is enabled, the output of 'top'
545 command will have 'Children' overhead column as well as 'Self' overhead
547 The default is 'true'.
550 This is identical to 'call-graph.record-mode', except it is
551 applicable only for 'top' subcommand. This option ONLY setup
552 the unwind method. To enable 'perf top' to actually use it,
553 the command line option -g must be specified.
557 This option can assign a tool to view manual pages when 'help'
558 subcommand was invoked. Supported tools are 'man', 'woman'
559 (with emacs client) and 'konqueror'. Default is 'man'.
561 New man viewer tool can be also added using 'man.<tool>.cmd'
562 or use different path using 'man.<tool>.path' config option.
566 When the subcommand is run on stdio, determine whether it uses
567 pager or not based on this value. Default is 'unspecified'.
571 This option decides which allocator is to be analyzed if neither
572 '--slab' nor '--page' option is used. Default is 'slab'.
576 This option can be 'cache', 'no-cache', 'skip' or 'mmap'.
577 'cache' is to post-process data and save/update the binaries into
578 the build-id cache (in ~/.debug). This is the default.
579 But if this option is 'no-cache', it will not update the build-id cache.
580 'skip' skips post-processing and does not update the cache.
581 'mmap' skips post-processing and reads build-ids from MMAP events.
584 This is identical to 'call-graph.record-mode', except it is
585 applicable only for 'record' subcommand. This option ONLY setup
586 the unwind method. To enable 'perf record' to actually use it,
587 the command line option -g must be specified.
590 Use 'n' control blocks in asynchronous (Posix AIO) trace writing
591 mode ('n' default: 1, max: 4).
594 Specify debuginfod URL to be used when cacheing perf.data binaries,
595 it follows the same syntax as the DEBUGINFOD_URLS variable, like:
597 http://192.168.122.174:8002
599 If the URLs is 'system', the value of DEBUGINFOD_URLS system environment
604 This option sets the number of columns to sort the result.
605 The default is 0, which means sorting by baseline.
606 Setting it to 1 will sort the result by delta (or other
607 compute method selected).
610 This options sets the method for computing the diff result.
611 Possible values are 'delta', 'delta-abs', 'ratio' and
612 'wdiff'. Default is 'delta'.
616 Allows adding a set of events to add to the ones specified
617 by the user, or use as a default one if none was specified.
618 The initial use case is to add augmented_raw_syscalls.o to
619 activate the 'perf trace' logic that looks for syscall
620 pointer contents after the normal tracepoint payload.
622 trace.args_alignment::
623 Number of columns to align the argument list, default is 70,
624 use 40 for the strace default, zero to no alignment.
627 Do not follow children threads.
629 trace.show_arg_names::
630 Should syscall argument names be printed? If not then trace.show_zeros
633 trace.show_duration::
634 Show syscall duration.
637 If set to 'yes' will show common string prefixes in tables. The default
638 is to remove the common prefix in things like "MAP_SHARED", showing just "SHARED".
640 trace.show_timestamp::
641 Show syscall start timestamp.
644 Do not suppress syscall arguments that are equal to zero.
646 trace.tracepoint_beautifiers::
647 Use "libtraceevent" to use that library to augment the tracepoint arguments,
648 "libbeauty", the default, to use the same argument beautifiers used in the
649 strace-like sys_enter+sys_exit lines.
653 Can be used to select the default tracer when neither -G nor
654 -F option is not specified. Possible values are 'function' and
660 Define how many ns worth of time to show
661 around samples in perf report sample context browser.
665 Any option defines a script that is added to the scripts menu
666 in the interactive perf browser and whose output is displayed.
667 The name of the option is the name, the value is a script command line.
668 The script gets the same options passed as a full perf script,
669 in particular -i perfdata file, --cpu, --tid
674 Limit the size of ordered_events queue, so we could control
675 allocation size of perf data files without proper finished
680 (boolean) Change the default for "--big-num". To make
681 "--no-big-num" the default, set "stat.big-num=false".
685 intel-pt.cache-divisor::
687 intel-pt.mispred-all::
688 If set, Intel PT decoder will set the mispred flag on all
692 If set and non-zero, the maximum number of unconditional
693 branches decoded without consuming any trace packets. If
694 the maximum is exceeded there will be a "Never-ending loop"
695 error. The default is 100000.
700 s390 only. The directory to save the auxiliary trace buffer
701 can be changed using this option. Ex, auxtrace.dumpdir=/tmp.
702 If the directory does not exist or has the wrong file type,
703 the current directory is used.
707 debug-log-buffer-size::
708 Log size in bytes to output when using the option --itrace=d+e
709 Refer 'itrace' option of linkperf:perf-script[1] or
710 linkperf:perf-report[1]. The default is 16384.
715 Base path for daemon data. All sessions data are stored under
722 Defines new record session for daemon. The value is record's
723 command line without the 'record' keyword.