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.
250 annotate.disassemblers::
251 Choose the disassembler to use: "objdump", "llvm", "capstone",
252 if not specified it will first try, if available, the "llvm" one,
253 then, if it fails, "capstone", and finally the original "objdump"
256 Choosing a different one is useful when handling some feature that
257 is known to be best support at some point by one of the options,
258 to compare the output when in doubt about some bug, etc.
260 This can be a list, in order of preference, the first one that works
261 finishes the process.
264 addr2line binary to use for file names and line numbers.
267 objdump binary to use for disassembly and annotations,
268 including in the 'perf test' command.
270 annotate.disassembler_style::
271 Use this to change the default disassembler style to some other value
272 supported by binutils, such as "intel", see the '-M' option help in the
275 annotate.hide_src_code::
276 If a program which is analyzed has source code,
277 this option lets 'annotate' print a list of assembly code with the source code.
278 For example, let's see a part of a program. There're four lines.
279 If this option is 'true', they can be printed
280 without source code from a program as below.
287 But if this option is 'false', source code of the part
288 can be also printed as below. Default is 'false'.
290 │ struct rb_node *rb_next(const struct rb_node *node)
295 │ struct rb_node *parent;
297 │ if (RB_EMPTY_NODE(node))
301 This option works with tui, stdio2 browsers.
303 annotate.use_offset::
304 Basing on a first address of a loaded function, offset can be used.
305 Instead of using original addresses of assembly code,
306 addresses subtracted from a base address can be printed.
307 Let's illustrate an example.
308 If a base address is 0XFFFFFFFF81624d50 as below,
310 ffffffff81624d50 <load0>
312 an address on assembly code has a specific absolute address as below
314 ffffffff816250b8:│ mov 0x8(%r14),%rdi
316 but if use_offset is 'true', an address subtracted from a base address is printed.
317 Default is true. This option is only applied to TUI.
319 368:│ mov 0x8(%r14),%rdi
321 This option works with tui, stdio2 browsers.
323 annotate.jump_arrows::
324 There can be jump instruction among assembly code.
325 Depending on a boolean value of jump_arrows,
326 arrows can be printed or not which represent
327 where do the instruction jump into as below.
329 │ ┌──jmp 1333
331 │1330:│ mov %r15,%r10
332 │1333:└─→cmp %r15,%r14
334 If jump_arrow is 'false', the arrows isn't printed as below.
339 │1330: mov %r15,%r10
340 │1333: cmp %r15,%r14
342 This option works with tui browser.
344 annotate.show_linenr::
345 When showing source code if this option is 'true',
346 line numbers are printed as below.
348 │1628 if (type & PERF_SAMPLE_IDENTIFIER) {
350 │1628 data->id = *array;
354 However if this option is 'false', they aren't printed as below.
357 │ if (type & PERF_SAMPLE_IDENTIFIER) {
359 │ data->id = *array;
363 This option works with tui, stdio2 browsers.
365 annotate.show_nr_jumps::
366 Let's see a part of assembly code.
368 │1382: movb $0x1,-0x270(%rbp)
370 If use this, the number of branches jumping to that address can be printed as below.
373 │1 1382: movb $0x1,-0x270(%rbp)
375 This option works with tui, stdio2 browsers.
377 annotate.show_total_period::
378 To compare two records on an instruction base, with this option
379 provided, display total number of samples that belong to a line
380 in assembly code. If this option is 'true', total periods are printed
381 instead of percent values as below.
383 302 │ mov %eax,%eax
385 But if this option is 'false', percent values for overhead are printed i.e.
388 99.93 │ mov %eax,%eax
390 This option works with tui, stdio2, stdio browsers.
392 annotate.show_nr_samples::
393 By default perf annotate shows percentage of samples. This option
394 can be used to print absolute number of samples. Ex, when set as
398 74.03 │ mov %fs:0x28,%rax
403 6 │ mov %fs:0x28,%rax
405 This option works with tui, stdio2, stdio browsers.
407 annotate.offset_level::
408 Default is '1', meaning just jump targets will have offsets show right beside
409 the instruction. When set to '2' 'call' instructions will also have its offsets
410 shown, 3 or higher will show offsets for all instructions.
412 This option works with tui, stdio2 browsers.
415 Demangle symbol names to human readable form. Default is 'true'.
417 annotate.demangle_kernel::
418 Demangle kernel symbol names to human readable form. Default is 'true'.
422 This option control the way to calculate overhead of filtered entries -
423 that means the value of this option is effective only if there's a
424 filter (by comm, dso or symbol name). Suppose a following example:
432 This is an original overhead and we'll filter out the first 'foo'
433 entry. The value of 'relative' would increase the overhead of 'bar'
434 and 'baz' to 50.00% for each, while 'absolute' would show their
435 current overhead (33.33%).
439 This option controls display of column headers (like 'Overhead' and 'Symbol')
440 in 'report' and 'top'. If this option is false, they are hidden.
441 This option is only applied to TUI.
444 The following controls the handling of call-graphs (obtained via the
445 -g/--call-graph options).
447 call-graph.record-mode::
448 The mode for user space can be 'fp' (frame pointer), 'dwarf'
449 and 'lbr'. The value 'dwarf' is effective only if libunwind
450 (or a recent version of libdw) is present on the system;
451 the value 'lbr' only works for certain cpus. The method for
452 kernel space is controlled not by this option but by the
453 kernel config (CONFIG_UNWINDER_*).
455 call-graph.dump-size::
456 The size of stack to dump in order to do post-unwinding. Default is 8192 (byte).
457 When using dwarf into record-mode, the default size will be used if omitted.
459 call-graph.print-type::
460 The print-types can be graph (graph absolute), fractal (graph relative),
461 flat and folded. This option controls a way to show overhead for each callchain
462 entry. Suppose a following example.
476 This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
477 half and half so 'fractal' shows 50.00% for each
478 (meaning that it assumes 100% total overhead of 'foo').
480 The 'graph' uses absolute overhead value of 'foo' as total so each of
481 'bar' and 'baz' callchain will have 20.00% of overhead.
482 If 'flat' is used, single column and linear exposure of call chains.
483 'folded' mean call chains are displayed in a line, separated by semicolons.
486 This option controls print order of callchains. The default is
487 'callee' which means callee is printed at top and then followed by its
488 caller and so on. The 'caller' prints it in reverse order.
490 If this option is not set and report.children or top.children is
491 set to true (or the equivalent command line option is given),
492 the default value of this option is changed to 'caller' for the
493 execution of 'perf report' or 'perf top'. Other commands will
494 still default to 'callee'.
496 call-graph.sort-key::
497 The callchains are merged if they contain same information.
498 The sort-key option determines a way to compare the callchains.
499 A value of 'sort-key' can be 'function' or 'address'.
500 The default is 'function'.
502 call-graph.threshold::
503 When there're many callchains it'd print tons of lines. So perf omits
504 small callchains under a certain overhead (threshold) and this option
505 control the threshold. Default is 0.5 (%). The overhead is calculated
506 by value depends on call-graph.print-type.
508 call-graph.print-limit::
509 This is a maximum number of lines of callchain printed for a single
510 histogram entry. Default is 0 which means no limitation.
514 Allows changing the default sort order from "comm,dso,symbol" to
515 some other default, for instance "sym,dso" may be more fitting for
517 report.percent-limit::
518 This one is mostly the same as call-graph.threshold but works for
519 histogram entries. Entries having an overhead lower than this
520 percentage will not be printed. Default is '0'. If percent-limit
521 is '10', only entries which have more than 10% of overhead will be
525 This option sets up the maximum allocation size of the internal
526 event queue for ordering events. Default is 0, meaning no limit.
529 'Children' means functions called from another function.
530 If this option is true, 'perf report' cumulates callchains of children
531 and show (accumulated) total overhead as well as 'Self' overhead.
532 Please refer to the 'perf report' manual. The default is 'true'.
535 This option is to show event group information together.
536 Example output with this turned on, notice that there is one column
537 per event in the group, ref-cycles and cycles:
539 # group: {ref-cycles,cycles}
542 # Samples: 7K of event 'anon group { ref-cycles, cycles }'
543 # Event count (approx.): 6876107743
545 # Overhead Command Shared Object Symbol
546 # ................ ....... ................. ...................
548 99.84% 99.76% noploop noploop [.] main
549 0.07% 0.00% noploop ld-2.15.so [.] strcmp
550 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
553 This option can change default stat behavior with empty results.
554 If it's set true, 'perf report --stat' will not show 0 stats.
558 Same as 'report.children'. So if it is enabled, the output of 'top'
559 command will have 'Children' overhead column as well as 'Self' overhead
561 The default is 'true'.
564 This is identical to 'call-graph.record-mode', except it is
565 applicable only for 'top' subcommand. This option ONLY setup
566 the unwind method. To enable 'perf top' to actually use it,
567 the command line option -g must be specified.
571 This option can assign a tool to view manual pages when 'help'
572 subcommand was invoked. Supported tools are 'man', 'woman'
573 (with emacs client) and 'konqueror'. Default is 'man'.
575 New man viewer tool can be also added using 'man.<tool>.cmd'
576 or use different path using 'man.<tool>.path' config option.
580 When the subcommand is run on stdio, determine whether it uses
581 pager or not based on this value. Default is 'unspecified'.
585 This option decides which allocator is to be analyzed if neither
586 '--slab' nor '--page' option is used. Default is 'slab'.
590 This option can be 'cache', 'no-cache', 'skip' or 'mmap'.
591 'cache' is to post-process data and save/update the binaries into
592 the build-id cache (in ~/.debug). This is the default.
593 But if this option is 'no-cache', it will not update the build-id cache.
594 'skip' skips post-processing and does not update the cache.
595 'mmap' skips post-processing and reads build-ids from MMAP events.
598 This is identical to 'call-graph.record-mode', except it is
599 applicable only for 'record' subcommand. This option ONLY setup
600 the unwind method. To enable 'perf record' to actually use it,
601 the command line option -g must be specified.
604 Use 'n' control blocks in asynchronous (Posix AIO) trace writing
605 mode ('n' default: 1, max: 4).
608 Specify debuginfod URL to be used when cacheing perf.data binaries,
609 it follows the same syntax as the DEBUGINFOD_URLS variable, like:
611 http://192.168.122.174:8002
613 If the URLs is 'system', the value of DEBUGINFOD_URLS system environment
618 This option sets the number of columns to sort the result.
619 The default is 0, which means sorting by baseline.
620 Setting it to 1 will sort the result by delta (or other
621 compute method selected).
624 This options sets the method for computing the diff result.
625 Possible values are 'delta', 'delta-abs', 'ratio' and
626 'wdiff'. Default is 'delta'.
630 Allows adding a set of events to add to the ones specified
631 by the user, or use as a default one if none was specified.
632 The initial use case is to add augmented_raw_syscalls.o to
633 activate the 'perf trace' logic that looks for syscall
634 pointer contents after the normal tracepoint payload.
636 trace.args_alignment::
637 Number of columns to align the argument list, default is 70,
638 use 40 for the strace default, zero to no alignment.
641 Do not follow children threads.
643 trace.show_arg_names::
644 Should syscall argument names be printed? If not then trace.show_zeros
647 trace.show_duration::
648 Show syscall duration.
651 If set to 'yes' will show common string prefixes in tables. The default
652 is to remove the common prefix in things like "MAP_SHARED", showing just "SHARED".
654 trace.show_timestamp::
655 Show syscall start timestamp.
658 Do not suppress syscall arguments that are equal to zero.
660 trace.tracepoint_beautifiers::
661 Use "libtraceevent" to use that library to augment the tracepoint arguments,
662 "libbeauty", the default, to use the same argument beautifiers used in the
663 strace-like sys_enter+sys_exit lines.
667 Can be used to select the default tracer when neither -G nor
668 -F option is not specified. Possible values are 'function' and
674 Define how many ns worth of time to show
675 around samples in perf report sample context browser.
679 Any option defines a script that is added to the scripts menu
680 in the interactive perf browser and whose output is displayed.
681 The name of the option is the name, the value is a script command line.
682 The script gets the same options passed as a full perf script,
683 in particular -i perfdata file, --cpu, --tid
688 Limit the size of ordered_events queue, so we could control
689 allocation size of perf data files without proper finished
694 (boolean) Change the default for "--big-num". To make
695 "--no-big-num" the default, set "stat.big-num=false".
699 intel-pt.cache-divisor::
701 intel-pt.mispred-all::
702 If set, Intel PT decoder will set the mispred flag on all
706 If set and non-zero, the maximum number of unconditional
707 branches decoded without consuming any trace packets. If
708 the maximum is exceeded there will be a "Never-ending loop"
709 error. The default is 100000.
714 s390 only. The directory to save the auxiliary trace buffer
715 can be changed using this option. Ex, auxtrace.dumpdir=/tmp.
716 If the directory does not exist or has the wrong file type,
717 the current directory is used.
721 debug-log-buffer-size::
722 Log size in bytes to output when using the option --itrace=d+e
723 Refer 'itrace' option of linkperf:perf-script[1] or
724 linkperf:perf-report[1]. The default is 16384.
729 Base path for daemon data. All sessions data are stored under
736 Defines new record session for daemon. The value is record's
737 command line without the 'record' keyword.