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 $HOME/.perfconfig like this:
73 # This is the config file, and
74 # a '#' and ';' character indicates a comment
80 medium = green, default
81 normal = lightgray, default
82 selected = white, lightgray
83 jump_arrows = blue, default
84 addr = magenta, default
88 # Defaults if linked with libslang
94 # Default, disable using /dev/null
102 show_nr_jumps = false
105 # Format can be man, info, web or html
113 # fp (framepointer), dwarf
121 sort_order = comm,dso,symbol
132 You can hide source code of annotate feature setting the config to false with
134 % perf config annotate.hide_src_code=true
136 If you want to add or modify several config items, you can do like
138 % perf config ui.show-headers=false kmem.default=slab
140 To modify the sort order of report functionality in user config file(i.e. `~/.perfconfig`), do
142 % perf config --user report.sort-order=srcline
144 To change colors of selected line to other foreground and background colors
145 in system config file (i.e. `$(sysconf)/perfconfig`), do
147 % perf config --system colors.selected=yellow,green
149 To query the record mode of call graph, do
151 % perf config call-graph.record-mode
153 If you want to know multiple config key/value pairs, you can do like
155 % perf config report.queue-size call-graph.order report.children
157 To query the config value of sort order of call graph in user config file (i.e. `~/.perfconfig`), do
159 % perf config --user call-graph.sort-order
161 To query the config value of buildid directory in system config file (i.e. `$(sysconf)/perfconfig`), do
163 % perf config --system buildid.dir
169 The variables for customizing the colors used in the output for the
170 'report', 'top' and 'annotate' in the TUI. They should specify the
171 foreground and background colors, separated by a comma, for example:
173 medium = green, lightgray
175 If you want to use the color configured for you terminal, just leave it
176 as 'default', for example:
178 medium = default, lightgray
181 red, yellow, green, cyan, gray, black, blue,
182 white, default, magenta, lightgray
185 'top' means a overhead percentage which is more than 5%.
186 And values of this variable specify percentage colors.
187 Basic key values are foreground-color 'red' and
188 background-color 'default'.
190 'medium' means a overhead percentage which has more than 0.5%.
191 Default values are 'green' and 'default'.
193 'normal' means the rest of overhead percentages
194 except 'top', 'medium', 'selected'.
195 Default values are 'lightgray' and 'default'.
197 This selects the colors for the current entry in a list of entries
198 from sub-commands (top, report, annotate).
199 Default values are 'black' and 'lightgray'.
201 Colors for jump arrows on assembly code listings
202 such as 'jns', 'jmp', 'jane', etc.
203 Default values are 'blue', 'default'.
205 This selects colors for addresses from 'annotate'.
206 Default values are 'magenta', 'default'.
208 Colors for headers in the output of a sub-commands (top, report).
209 Default values are 'white', 'blue'.
212 core.proc-map-timeout::
213 Sets a timeout (in milliseconds) for parsing /proc/<pid>/maps files.
214 Can be overridden by the --proc-map-timeout option on supported
215 subcommands. The default timeout is 500ms.
218 Subcommands that can be configured here are 'top', 'report' and 'annotate'.
219 These values are booleans, for example:
224 will make the TUI be the default for the 'top' subcommand. Those will be
225 available if the required libs were detected at tool build time.
229 Each executable and shared library in modern distributions comes with a
230 content based identifier that, if available, will be inserted in a
231 'perf.data' file header to, at analysis time find what is needed to do
232 symbol resolution, code annotation, etc.
234 The recording tools also stores a hard link or copy in a per-user
235 directory, $HOME/.debug/, of binaries, shared libraries, /proc/kallsyms
236 and /proc/kcore files to be used at analysis time.
238 The buildid.dir variable can be used to either change this directory
239 cache location, or to disable it altogether. If you want to disable it,
240 set buildid.dir to /dev/null. The default is $HOME/.debug
243 buildid-cache.debuginfod=URLs
244 Specify debuginfod URLs to be used when retrieving perf.data binaries,
245 it follows the same syntax as the DEBUGINFOD_URLS variable, like:
247 buildid-cache.debuginfod=http://192.168.122.174:8002
250 These are in control of addresses, jump function, source code
251 in lines of assembly code from a specific program.
254 addr2line binary to use for file names and line numbers.
257 objdump binary to use for disassembly and annotations.
259 annotate.disassembler_style::
260 Use this to change the default disassembler style to some other value
261 supported by binutils, such as "intel", see the '-M' option help in the
264 annotate.hide_src_code::
265 If a program which is analyzed has source code,
266 this option lets 'annotate' print a list of assembly code with the source code.
267 For example, let's see a part of a program. There're four lines.
268 If this option is 'true', they can be printed
269 without source code from a program as below.
276 But if this option is 'false', source code of the part
277 can be also printed as below. Default is 'false'.
279 │ struct rb_node *rb_next(const struct rb_node *node)
284 │ struct rb_node *parent;
286 │ if (RB_EMPTY_NODE(node))
290 This option works with tui, stdio2 browsers.
292 annotate.use_offset::
293 Basing on a first address of a loaded function, offset can be used.
294 Instead of using original addresses of assembly code,
295 addresses subtracted from a base address can be printed.
296 Let's illustrate an example.
297 If a base address is 0XFFFFFFFF81624d50 as below,
299 ffffffff81624d50 <load0>
301 an address on assembly code has a specific absolute address as below
303 ffffffff816250b8:│ mov 0x8(%r14),%rdi
305 but if use_offset is 'true', an address subtracted from a base address is printed.
306 Default is true. This option is only applied to TUI.
308 368:│ mov 0x8(%r14),%rdi
310 This option works with tui, stdio2 browsers.
312 annotate.jump_arrows::
313 There can be jump instruction among assembly code.
314 Depending on a boolean value of jump_arrows,
315 arrows can be printed or not which represent
316 where do the instruction jump into as below.
318 │ ┌──jmp 1333
320 │1330:│ mov %r15,%r10
321 │1333:└─→cmp %r15,%r14
323 If jump_arrow is 'false', the arrows isn't printed as below.
328 │1330: mov %r15,%r10
329 │1333: cmp %r15,%r14
331 This option works with tui browser.
333 annotate.show_linenr::
334 When showing source code if this option is 'true',
335 line numbers are printed as below.
337 │1628 if (type & PERF_SAMPLE_IDENTIFIER) {
339 │1628 data->id = *array;
343 However if this option is 'false', they aren't printed as below.
346 │ if (type & PERF_SAMPLE_IDENTIFIER) {
348 │ data->id = *array;
352 This option works with tui, stdio2 browsers.
354 annotate.show_nr_jumps::
355 Let's see a part of assembly code.
357 │1382: movb $0x1,-0x270(%rbp)
359 If use this, the number of branches jumping to that address can be printed as below.
362 │1 1382: movb $0x1,-0x270(%rbp)
364 This option works with tui, stdio2 browsers.
366 annotate.show_total_period::
367 To compare two records on an instruction base, with this option
368 provided, display total number of samples that belong to a line
369 in assembly code. If this option is 'true', total periods are printed
370 instead of percent values as below.
372 302 │ mov %eax,%eax
374 But if this option is 'false', percent values for overhead are printed i.e.
377 99.93 │ mov %eax,%eax
379 This option works with tui, stdio2, stdio browsers.
381 annotate.show_nr_samples::
382 By default perf annotate shows percentage of samples. This option
383 can be used to print absolute number of samples. Ex, when set as
387 74.03 │ mov %fs:0x28,%rax
392 6 │ mov %fs:0x28,%rax
394 This option works with tui, stdio2, stdio browsers.
396 annotate.offset_level::
397 Default is '1', meaning just jump targets will have offsets show right beside
398 the instruction. When set to '2' 'call' instructions will also have its offsets
399 shown, 3 or higher will show offsets for all instructions.
401 This option works with tui, stdio2 browsers.
404 Demangle symbol names to human readable form. Default is 'true'.
406 annotate.demangle_kernel::
407 Demangle kernel symbol names to human readable form. Default is 'true'.
411 This option control the way to calculate overhead of filtered entries -
412 that means the value of this option is effective only if there's a
413 filter (by comm, dso or symbol name). Suppose a following example:
421 This is an original overhead and we'll filter out the first 'foo'
422 entry. The value of 'relative' would increase the overhead of 'bar'
423 and 'baz' to 50.00% for each, while 'absolute' would show their
424 current overhead (33.33%).
428 This option controls display of column headers (like 'Overhead' and 'Symbol')
429 in 'report' and 'top'. If this option is false, they are hidden.
430 This option is only applied to TUI.
433 The following controls the handling of call-graphs (obtained via the
434 -g/--call-graph options).
436 call-graph.record-mode::
437 The mode for user space can be 'fp' (frame pointer), 'dwarf'
438 and 'lbr'. The value 'dwarf' is effective only if libunwind
439 (or a recent version of libdw) is present on the system;
440 the value 'lbr' only works for certain cpus. The method for
441 kernel space is controlled not by this option but by the
442 kernel config (CONFIG_UNWINDER_*).
444 call-graph.dump-size::
445 The size of stack to dump in order to do post-unwinding. Default is 8192 (byte).
446 When using dwarf into record-mode, the default size will be used if omitted.
448 call-graph.print-type::
449 The print-types can be graph (graph absolute), fractal (graph relative),
450 flat and folded. This option controls a way to show overhead for each callchain
451 entry. Suppose a following example.
465 This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
466 half and half so 'fractal' shows 50.00% for each
467 (meaning that it assumes 100% total overhead of 'foo').
469 The 'graph' uses absolute overhead value of 'foo' as total so each of
470 'bar' and 'baz' callchain will have 20.00% of overhead.
471 If 'flat' is used, single column and linear exposure of call chains.
472 'folded' mean call chains are displayed in a line, separated by semicolons.
475 This option controls print order of callchains. The default is
476 'callee' which means callee is printed at top and then followed by its
477 caller and so on. The 'caller' prints it in reverse order.
479 If this option is not set and report.children or top.children is
480 set to true (or the equivalent command line option is given),
481 the default value of this option is changed to 'caller' for the
482 execution of 'perf report' or 'perf top'. Other commands will
483 still default to 'callee'.
485 call-graph.sort-key::
486 The callchains are merged if they contain same information.
487 The sort-key option determines a way to compare the callchains.
488 A value of 'sort-key' can be 'function' or 'address'.
489 The default is 'function'.
491 call-graph.threshold::
492 When there're many callchains it'd print tons of lines. So perf omits
493 small callchains under a certain overhead (threshold) and this option
494 control the threshold. Default is 0.5 (%). The overhead is calculated
495 by value depends on call-graph.print-type.
497 call-graph.print-limit::
498 This is a maximum number of lines of callchain printed for a single
499 histogram entry. Default is 0 which means no limitation.
503 Allows changing the default sort order from "comm,dso,symbol" to
504 some other default, for instance "sym,dso" may be more fitting for
506 report.percent-limit::
507 This one is mostly the same as call-graph.threshold but works for
508 histogram entries. Entries having an overhead lower than this
509 percentage will not be printed. Default is '0'. If percent-limit
510 is '10', only entries which have more than 10% of overhead will be
514 This option sets up the maximum allocation size of the internal
515 event queue for ordering events. Default is 0, meaning no limit.
518 'Children' means functions called from another function.
519 If this option is true, 'perf report' cumulates callchains of children
520 and show (accumulated) total overhead as well as 'Self' overhead.
521 Please refer to the 'perf report' manual. The default is 'true'.
524 This option is to show event group information together.
525 Example output with this turned on, notice that there is one column
526 per event in the group, ref-cycles and cycles:
528 # group: {ref-cycles,cycles}
531 # Samples: 7K of event 'anon group { ref-cycles, cycles }'
532 # Event count (approx.): 6876107743
534 # Overhead Command Shared Object Symbol
535 # ................ ....... ................. ...................
537 99.84% 99.76% noploop noploop [.] main
538 0.07% 0.00% noploop ld-2.15.so [.] strcmp
539 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
542 This option can change default stat behavior with empty results.
543 If it's set true, 'perf report --stat' will not show 0 stats.
547 Same as 'report.children'. So if it is enabled, the output of 'top'
548 command will have 'Children' overhead column as well as 'Self' overhead
550 The default is 'true'.
553 This is identical to 'call-graph.record-mode', except it is
554 applicable only for 'top' subcommand. This option ONLY setup
555 the unwind method. To enable 'perf top' to actually use it,
556 the command line option -g must be specified.
560 This option can assign a tool to view manual pages when 'help'
561 subcommand was invoked. Supported tools are 'man', 'woman'
562 (with emacs client) and 'konqueror'. Default is 'man'.
564 New man viewer tool can be also added using 'man.<tool>.cmd'
565 or use different path using 'man.<tool>.path' config option.
569 When the subcommand is run on stdio, determine whether it uses
570 pager or not based on this value. Default is 'unspecified'.
574 This option decides which allocator is to be analyzed if neither
575 '--slab' nor '--page' option is used. Default is 'slab'.
579 This option can be 'cache', 'no-cache', 'skip' or 'mmap'.
580 'cache' is to post-process data and save/update the binaries into
581 the build-id cache (in ~/.debug). This is the default.
582 But if this option is 'no-cache', it will not update the build-id cache.
583 'skip' skips post-processing and does not update the cache.
584 'mmap' skips post-processing and reads build-ids from MMAP events.
587 This is identical to 'call-graph.record-mode', except it is
588 applicable only for 'record' subcommand. This option ONLY setup
589 the unwind method. To enable 'perf record' to actually use it,
590 the command line option -g must be specified.
593 Use 'n' control blocks in asynchronous (Posix AIO) trace writing
594 mode ('n' default: 1, max: 4).
597 Specify debuginfod URL to be used when cacheing perf.data binaries,
598 it follows the same syntax as the DEBUGINFOD_URLS variable, like:
600 http://192.168.122.174:8002
602 If the URLs is 'system', the value of DEBUGINFOD_URLS system environment
607 This option sets the number of columns to sort the result.
608 The default is 0, which means sorting by baseline.
609 Setting it to 1 will sort the result by delta (or other
610 compute method selected).
613 This options sets the method for computing the diff result.
614 Possible values are 'delta', 'delta-abs', 'ratio' and
615 'wdiff'. Default is 'delta'.
619 Allows adding a set of events to add to the ones specified
620 by the user, or use as a default one if none was specified.
621 The initial use case is to add augmented_raw_syscalls.o to
622 activate the 'perf trace' logic that looks for syscall
623 pointer contents after the normal tracepoint payload.
625 trace.args_alignment::
626 Number of columns to align the argument list, default is 70,
627 use 40 for the strace default, zero to no alignment.
630 Do not follow children threads.
632 trace.show_arg_names::
633 Should syscall argument names be printed? If not then trace.show_zeros
636 trace.show_duration::
637 Show syscall duration.
640 If set to 'yes' will show common string prefixes in tables. The default
641 is to remove the common prefix in things like "MAP_SHARED", showing just "SHARED".
643 trace.show_timestamp::
644 Show syscall start timestamp.
647 Do not suppress syscall arguments that are equal to zero.
649 trace.tracepoint_beautifiers::
650 Use "libtraceevent" to use that library to augment the tracepoint arguments,
651 "libbeauty", the default, to use the same argument beautifiers used in the
652 strace-like sys_enter+sys_exit lines.
656 Can be used to select the default tracer when neither -G nor
657 -F option is not specified. Possible values are 'function' and
662 Path to clang. If omit, search it from $PATH.
664 llvm.clang-bpf-cmd-template::
665 Cmdline template. Below lines show its default value. Environment
666 variable is used to pass options.
667 "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
668 "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
669 "$CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS " \
670 "-Wno-unused-value -Wno-pointer-sign " \
671 "-working-directory $WORKING_DIR " \
672 "-c \"$CLANG_SOURCE\" --target=bpf $CLANG_EMIT_LLVM -O2 -o - $LLVM_OPTIONS_PIPE"
675 Options passed to clang.
678 kbuild directory. If not set, use /lib/modules/`uname -r`/build.
679 If set to "" deliberately, skip kernel header auto-detector.
682 Options passed to 'make' when detecting kernel header options.
685 Enable perf dump BPF object files compiled by LLVM.
688 Options passed to llc.
693 Define how many ns worth of time to show
694 around samples in perf report sample context browser.
698 Any option defines a script that is added to the scripts menu
699 in the interactive perf browser and whose output is displayed.
700 The name of the option is the name, the value is a script command line.
701 The script gets the same options passed as a full perf script,
702 in particular -i perfdata file, --cpu, --tid
707 Limit the size of ordered_events queue, so we could control
708 allocation size of perf data files without proper finished
713 (boolean) Change the default for "--big-num". To make
714 "--no-big-num" the default, set "stat.big-num=false".
718 intel-pt.cache-divisor::
720 intel-pt.mispred-all::
721 If set, Intel PT decoder will set the mispred flag on all
725 If set and non-zero, the maximum number of unconditional
726 branches decoded without consuming any trace packets. If
727 the maximum is exceeded there will be a "Never-ending loop"
728 error. The default is 100000.
733 s390 only. The directory to save the auxiliary trace buffer
734 can be changed using this option. Ex, auxtrace.dumpdir=/tmp.
735 If the directory does not exist or has the wrong file type,
736 the current directory is used.
740 debug-log-buffer-size::
741 Log size in bytes to output when using the option --itrace=d+e
742 Refer 'itrace' option of linkperf:perf-script[1] or
743 linkperf:perf-report[1]. The default is 16384.
748 Base path for daemon data. All sessions data are stored under
755 Defines new record session for daemon. The value is record's
756 command line without the 'record' keyword.