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 $HOME/.perfconfig like this:
73 # This is the config file, and
74 # a '#' and ';' character indicates a comment
80 medium = green, default
81 normal = lightgray, default
82 selected = white, lightgray
83 jump_arrows = blue, default
84 addr = magenta, default
88 # Defaults if linked with libslang
94 # Default, disable using /dev/null
102 show_nr_jumps = false
105 # Format can be man, info, web or html
113 # fp (framepointer), dwarf
121 sort_order = comm,dso,symbol
131 You can hide source code of annotate feature setting the config to false with
133 % perf config annotate.hide_src_code=true
135 If you want to add or modify several config items, you can do like
137 % perf config ui.show-headers=false kmem.default=slab
139 To modify the sort order of report functionality in user config file(i.e. `~/.perfconfig`), do
141 % perf config --user report.sort-order=srcline
143 To change colors of selected line to other foreground and background colors
144 in system config file (i.e. `$(sysconf)/perfconfig`), do
146 % perf config --system colors.selected=yellow,green
148 To query the record mode of call graph, do
150 % perf config call-graph.record-mode
152 If you want to know multiple config key/value pairs, you can do like
154 % perf config report.queue-size call-graph.order report.children
156 To query the config value of sort order of call graph in user config file (i.e. `~/.perfconfig`), do
158 % perf config --user call-graph.sort-order
160 To query the config value of buildid directory in system config file (i.e. `$(sysconf)/perfconfig`), do
162 % perf config --system buildid.dir
168 The variables for customizing the colors used in the output for the
169 'report', 'top' and 'annotate' in the TUI. They should specify the
170 foreground and background colors, separated by a comma, for example:
172 medium = green, lightgray
174 If you want to use the color configured for you terminal, just leave it
175 as 'default', for example:
177 medium = default, lightgray
180 red, yellow, green, cyan, gray, black, blue,
181 white, default, magenta, lightgray
184 'top' means a overhead percentage which is more than 5%.
185 And values of this variable specify percentage colors.
186 Basic key values are foreground-color 'red' and
187 background-color 'default'.
189 'medium' means a overhead percentage which has more than 0.5%.
190 Default values are 'green' and 'default'.
192 'normal' means the rest of overhead percentages
193 except 'top', 'medium', 'selected'.
194 Default values are 'lightgray' and 'default'.
196 This selects the colors for the current entry in a list of entries
197 from sub-commands (top, report, annotate).
198 Default values are 'black' and 'lightgray'.
200 Colors for jump arrows on assembly code listings
201 such as 'jns', 'jmp', 'jane', etc.
202 Default values are 'blue', 'default'.
204 This selects colors for addresses from 'annotate'.
205 Default values are 'magenta', 'default'.
207 Colors for headers in the output of a sub-commands (top, report).
208 Default values are 'white', 'blue'.
211 core.proc-map-timeout::
212 Sets a timeout (in milliseconds) for parsing /proc/<pid>/maps files.
213 Can be overridden by the --proc-map-timeout option on supported
214 subcommands. The default timeout is 500ms.
217 Subcommands that can be configured here are 'top', 'report' and 'annotate'.
218 These values are booleans, for example:
223 will make the TUI be the default for the 'top' subcommand. Those will be
224 available if the required libs were detected at tool build time.
228 Each executable and shared library in modern distributions comes with a
229 content based identifier that, if available, will be inserted in a
230 'perf.data' file header to, at analysis time find what is needed to do
231 symbol resolution, code annotation, etc.
233 The recording tools also stores a hard link or copy in a per-user
234 directory, $HOME/.debug/, of binaries, shared libraries, /proc/kallsyms
235 and /proc/kcore files to be used at analysis time.
237 The buildid.dir variable can be used to either change this directory
238 cache location, or to disable it altogether. If you want to disable it,
239 set buildid.dir to /dev/null. The default is $HOME/.debug
242 buildid-cache.debuginfod=URLs
243 Specify debuginfod URLs to be used when retrieving perf.data binaries,
244 it follows the same syntax as the DEBUGINFOD_URLS variable, like:
246 buildid-cache.debuginfod=http://192.168.122.174:8002
249 These are in control of addresses, jump function, source code
250 in lines of assembly code from a specific program.
252 annotate.disassembler_style:
253 Use this to change the default disassembler style to some other value
254 supported by binutils, such as "intel", see the '-M' option help in the
257 annotate.hide_src_code::
258 If a program which is analyzed has source code,
259 this option lets 'annotate' print a list of assembly code with the source code.
260 For example, let's see a part of a program. There're four lines.
261 If this option is 'true', they can be printed
262 without source code from a program as below.
269 But if this option is 'false', source code of the part
270 can be also printed as below. Default is 'false'.
272 │ struct rb_node *rb_next(const struct rb_node *node)
277 │ struct rb_node *parent;
279 │ if (RB_EMPTY_NODE(node))
283 This option works with tui, stdio2 browsers.
285 annotate.use_offset::
286 Basing on a first address of a loaded function, offset can be used.
287 Instead of using original addresses of assembly code,
288 addresses subtracted from a base address can be printed.
289 Let's illustrate an example.
290 If a base address is 0XFFFFFFFF81624d50 as below,
292 ffffffff81624d50 <load0>
294 an address on assembly code has a specific absolute address as below
296 ffffffff816250b8:│ mov 0x8(%r14),%rdi
298 but if use_offset is 'true', an address subtracted from a base address is printed.
299 Default is true. This option is only applied to TUI.
301 368:│ mov 0x8(%r14),%rdi
303 This option works with tui, stdio2 browsers.
305 annotate.jump_arrows::
306 There can be jump instruction among assembly code.
307 Depending on a boolean value of jump_arrows,
308 arrows can be printed or not which represent
309 where do the instruction jump into as below.
311 │ ┌──jmp 1333
313 │1330:│ mov %r15,%r10
314 │1333:└─→cmp %r15,%r14
316 If jump_arrow is 'false', the arrows isn't printed as below.
321 │1330: mov %r15,%r10
322 │1333: cmp %r15,%r14
324 This option works with tui browser.
326 annotate.show_linenr::
327 When showing source code if this option is 'true',
328 line numbers are printed as below.
330 │1628 if (type & PERF_SAMPLE_IDENTIFIER) {
332 │1628 data->id = *array;
336 However if this option is 'false', they aren't printed as below.
339 │ if (type & PERF_SAMPLE_IDENTIFIER) {
341 │ data->id = *array;
345 This option works with tui, stdio2 browsers.
347 annotate.show_nr_jumps::
348 Let's see a part of assembly code.
350 │1382: movb $0x1,-0x270(%rbp)
352 If use this, the number of branches jumping to that address can be printed as below.
355 │1 1382: movb $0x1,-0x270(%rbp)
357 This option works with tui, stdio2 browsers.
359 annotate.show_total_period::
360 To compare two records on an instruction base, with this option
361 provided, display total number of samples that belong to a line
362 in assembly code. If this option is 'true', total periods are printed
363 instead of percent values as below.
365 302 │ mov %eax,%eax
367 But if this option is 'false', percent values for overhead are printed i.e.
370 99.93 │ mov %eax,%eax
372 This option works with tui, stdio2, stdio browsers.
374 annotate.show_nr_samples::
375 By default perf annotate shows percentage of samples. This option
376 can be used to print absolute number of samples. Ex, when set as
380 74.03 │ mov %fs:0x28,%rax
385 6 │ mov %fs:0x28,%rax
387 This option works with tui, stdio2, stdio browsers.
389 annotate.offset_level::
390 Default is '1', meaning just jump targets will have offsets show right beside
391 the instruction. When set to '2' 'call' instructions will also have its offsets
392 shown, 3 or higher will show offsets for all instructions.
394 This option works with tui, stdio2 browsers.
398 This option control the way to calculate overhead of filtered entries -
399 that means the value of this option is effective only if there's a
400 filter (by comm, dso or symbol name). Suppose a following example:
408 This is an original overhead and we'll filter out the first 'foo'
409 entry. The value of 'relative' would increase the overhead of 'bar'
410 and 'baz' to 50.00% for each, while 'absolute' would show their
411 current overhead (33.33%).
415 This option controls display of column headers (like 'Overhead' and 'Symbol')
416 in 'report' and 'top'. If this option is false, they are hidden.
417 This option is only applied to TUI.
420 The following controls the handling of call-graphs (obtained via the
421 -g/--call-graph options).
423 call-graph.record-mode::
424 The mode for user space can be 'fp' (frame pointer), 'dwarf'
425 and 'lbr'. The value 'dwarf' is effective only if libunwind
426 (or a recent version of libdw) is present on the system;
427 the value 'lbr' only works for certain cpus. The method for
428 kernel space is controlled not by this option but by the
429 kernel config (CONFIG_UNWINDER_*).
431 call-graph.dump-size::
432 The size of stack to dump in order to do post-unwinding. Default is 8192 (byte).
433 When using dwarf into record-mode, the default size will be used if omitted.
435 call-graph.print-type::
436 The print-types can be graph (graph absolute), fractal (graph relative),
437 flat and folded. This option controls a way to show overhead for each callchain
438 entry. Suppose a following example.
452 This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
453 half and half so 'fractal' shows 50.00% for each
454 (meaning that it assumes 100% total overhead of 'foo').
456 The 'graph' uses absolute overhead value of 'foo' as total so each of
457 'bar' and 'baz' callchain will have 20.00% of overhead.
458 If 'flat' is used, single column and linear exposure of call chains.
459 'folded' mean call chains are displayed in a line, separated by semicolons.
462 This option controls print order of callchains. The default is
463 'callee' which means callee is printed at top and then followed by its
464 caller and so on. The 'caller' prints it in reverse order.
466 If this option is not set and report.children or top.children is
467 set to true (or the equivalent command line option is given),
468 the default value of this option is changed to 'caller' for the
469 execution of 'perf report' or 'perf top'. Other commands will
470 still default to 'callee'.
472 call-graph.sort-key::
473 The callchains are merged if they contain same information.
474 The sort-key option determines a way to compare the callchains.
475 A value of 'sort-key' can be 'function' or 'address'.
476 The default is 'function'.
478 call-graph.threshold::
479 When there're many callchains it'd print tons of lines. So perf omits
480 small callchains under a certain overhead (threshold) and this option
481 control the threshold. Default is 0.5 (%). The overhead is calculated
482 by value depends on call-graph.print-type.
484 call-graph.print-limit::
485 This is a maximum number of lines of callchain printed for a single
486 histogram entry. Default is 0 which means no limitation.
490 Allows changing the default sort order from "comm,dso,symbol" to
491 some other default, for instance "sym,dso" may be more fitting for
493 report.percent-limit::
494 This one is mostly the same as call-graph.threshold but works for
495 histogram entries. Entries having an overhead lower than this
496 percentage will not be printed. Default is '0'. If percent-limit
497 is '10', only entries which have more than 10% of overhead will be
501 This option sets up the maximum allocation size of the internal
502 event queue for ordering events. Default is 0, meaning no limit.
505 'Children' means functions called from another function.
506 If this option is true, 'perf report' cumulates callchains of children
507 and show (accumulated) total overhead as well as 'Self' overhead.
508 Please refer to the 'perf report' manual. The default is 'true'.
511 This option is to show event group information together.
512 Example output with this turned on, notice that there is one column
513 per event in the group, ref-cycles and cycles:
515 # group: {ref-cycles,cycles}
518 # Samples: 7K of event 'anon group { ref-cycles, cycles }'
519 # Event count (approx.): 6876107743
521 # Overhead Command Shared Object Symbol
522 # ................ ....... ................. ...................
524 99.84% 99.76% noploop noploop [.] main
525 0.07% 0.00% noploop ld-2.15.so [.] strcmp
526 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
530 Same as 'report.children'. So if it is enabled, the output of 'top'
531 command will have 'Children' overhead column as well as 'Self' overhead
533 The default is 'true'.
536 This is identical to 'call-graph.record-mode', except it is
537 applicable only for 'top' subcommand. This option ONLY setup
538 the unwind method. To enable 'perf top' to actually use it,
539 the command line option -g must be specified.
543 This option can assign a tool to view manual pages when 'help'
544 subcommand was invoked. Supported tools are 'man', 'woman'
545 (with emacs client) and 'konqueror'. Default is 'man'.
547 New man viewer tool can be also added using 'man.<tool>.cmd'
548 or use different path using 'man.<tool>.path' config option.
552 When the subcommand is run on stdio, determine whether it uses
553 pager or not based on this value. Default is 'unspecified'.
557 This option decides which allocator is to be analyzed if neither
558 '--slab' nor '--page' option is used. Default is 'slab'.
562 This option can be 'cache', 'no-cache', 'skip' or 'mmap'.
563 'cache' is to post-process data and save/update the binaries into
564 the build-id cache (in ~/.debug). This is the default.
565 But if this option is 'no-cache', it will not update the build-id cache.
566 'skip' skips post-processing and does not update the cache.
567 'mmap' skips post-processing and reads build-ids from MMAP events.
570 This is identical to 'call-graph.record-mode', except it is
571 applicable only for 'record' subcommand. This option ONLY setup
572 the unwind method. To enable 'perf record' to actually use it,
573 the command line option -g must be specified.
576 Use 'n' control blocks in asynchronous (Posix AIO) trace writing
577 mode ('n' default: 1, max: 4).
581 This option sets the number of columns to sort the result.
582 The default is 0, which means sorting by baseline.
583 Setting it to 1 will sort the result by delta (or other
584 compute method selected).
587 This options sets the method for computing the diff result.
588 Possible values are 'delta', 'delta-abs', 'ratio' and
589 'wdiff'. Default is 'delta'.
593 Allows adding a set of events to add to the ones specified
594 by the user, or use as a default one if none was specified.
595 The initial use case is to add augmented_raw_syscalls.o to
596 activate the 'perf trace' logic that looks for syscall
597 pointer contents after the normal tracepoint payload.
599 trace.args_alignment::
600 Number of columns to align the argument list, default is 70,
601 use 40 for the strace default, zero to no alignment.
604 Do not follow children threads.
606 trace.show_arg_names::
607 Should syscall argument names be printed? If not then trace.show_zeros
610 trace.show_duration::
611 Show syscall duration.
614 If set to 'yes' will show common string prefixes in tables. The default
615 is to remove the common prefix in things like "MAP_SHARED", showing just "SHARED".
617 trace.show_timestamp::
618 Show syscall start timestamp.
621 Do not suppress syscall arguments that are equal to zero.
623 trace.tracepoint_beautifiers::
624 Use "libtraceevent" to use that library to augment the tracepoint arguments,
625 "libbeauty", the default, to use the same argument beautifiers used in the
626 strace-like sys_enter+sys_exit lines.
630 Can be used to select the default tracer when neither -G nor
631 -F option is not specified. Possible values are 'function' and
636 Path to clang. If omit, search it from $PATH.
638 llvm.clang-bpf-cmd-template::
639 Cmdline template. Below lines show its default value. Environment
640 variable is used to pass options.
641 "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
642 "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
643 "$CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS " \
644 "-Wno-unused-value -Wno-pointer-sign " \
645 "-working-directory $WORKING_DIR " \
646 "-c \"$CLANG_SOURCE\" -target bpf $CLANG_EMIT_LLVM -O2 -o - $LLVM_OPTIONS_PIPE"
649 Options passed to clang.
652 kbuild directory. If not set, use /lib/modules/`uname -r`/build.
653 If set to "" deliberately, skip kernel header auto-detector.
656 Options passed to 'make' when detecting kernel header options.
659 Enable perf dump BPF object files compiled by LLVM.
662 Options passed to llc.
667 Define how many ns worth of time to show
668 around samples in perf report sample context browser.
672 Any option defines a script that is added to the scripts menu
673 in the interactive perf browser and whose output is displayed.
674 The name of the option is the name, the value is a script command line.
675 The script gets the same options passed as a full perf script,
676 in particular -i perfdata file, --cpu, --tid
681 Limit the size of ordered_events queue, so we could control
682 allocation size of perf data files without proper finished
687 (boolean) Change the default for "--big-num". To make
688 "--no-big-num" the default, set "stat.big-num=false".
692 intel-pt.cache-divisor::
694 intel-pt.mispred-all::
695 If set, Intel PT decoder will set the mispred flag on all
701 s390 only. The directory to save the auxiliary trace buffer
702 can be changed using this option. Ex, auxtrace.dumpdir=/tmp.
703 If the directory does not exist or has the wrong file type,
704 the current directory is used.
709 Base path for daemon data. All sessions data are stored under
716 Defines new record session for daemon. The value is record's
717 command line without the 'record' keyword.