| blob | c4dd23c4b47811e7c896fe90532bdc11ac2580b9 |
1 perf-config(1)
2 ==============
4 NAME
5 ----
6 perf-config - Get and set variables in a configuration file.
8 SYNOPSIS
9 --------
10 [verse]
11 'perf config' [<file-option>] [section.name[=value] ...]
12 or
13 'perf config' [<file-option>] -l | --list
15 DESCRIPTION
16 -----------
17 You can manage variables in a configuration file with this command.
19 OPTIONS
20 -------
22 -l::
23 --list::
24 Show current config variables, name and value, for all sections.
26 --user::
27 For writing and reading options: write to user
28 '$HOME/.perfconfig' file or read it.
30 --system::
31 For writing and reading options: write to system-wide
32 '$(sysconfdir)/perfconfig' or read it.
34 CONFIGURATION FILE
35 ------------------
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
45 variable.
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.
51 Syntax
52 ~~~~~~
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:
59 [section]
60 name1 = value1
61 name2 = value2
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.
67 Example
68 ~~~~~~~
70 Given a $HOME/.perfconfig like this:
72 #
73 # This is the config file, and
74 # a '#' and ';' character indicates a comment
75 #
77 [colors]
78 # Color variables
79 top = red, default
80 medium = green, default
81 normal = lightgray, default
82 selected = white, lightgray
83 jump_arrows = blue, default
84 addr = magenta, default
85 root = white, blue
87 [tui]
88 # Defaults if linked with libslang
89 report = on
90 annotate = on
91 top = on
93 [buildid]
94 # Default, disable using /dev/null
95 dir = ~/.debug
97 [annotate]
98 # Defaults
99 hide_src_code = false
100 use_offset = true
101 jump_arrows = true
102 show_nr_jumps = false
104 [help]
105 # Format can be man, info, web or html
106 format = man
107 autocorrect = 0
109 [ui]
110 show-headers = true
112 [call-graph]
113 # fp (framepointer), dwarf
114 record-mode = fp
115 print-type = graph
116 order = caller
117 sort-key = function
119 [report]
120 # Defaults
121 sort_order = comm,dso,symbol
122 percent-limit = 0
123 queue-size = 0
124 children = true
125 group = true
127 [llvm]
128 dump-obj = true
129 clang-opt = -g
131 You can hide source code of annotate feature setting the config to false with
133 % perf config annotate.hide_src_code=true
135 If you want to add or modify several config items, you can do like
137 % perf config ui.show-headers=false kmem.default=slab
139 To modify the sort order of report functionality in user config file(i.e. `~/.perfconfig`), do
141 % perf config --user report sort-order=srcline
143 To change colors of selected line to other foreground and background colors
144 in system config file (i.e. `$(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
164 Variables
165 ~~~~~~~~~
167 colors.*::
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
179 Available colors:
180 red, yellow, green, cyan, gray, black, blue,
181 white, default, magenta, lightgray
183 colors.top::
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'.
188 colors.medium::
189 'medium' means a overhead percentage which has more than 0.5%.
190 Default values are 'green' and 'default'.
191 colors.normal::
192 'normal' means the rest of overhead percentages
193 except 'top', 'medium', 'selected'.
194 Default values are 'lightgray' and 'default'.
195 colors.selected::
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'.
199 colors.jump_arrows::
200 Colors for jump arrows on assembly code listings
201 such as 'jns', 'jmp', 'jane', etc.
202 Default values are 'blue', 'default'.
203 colors.addr::
204 This selects colors for addresses from 'annotate'.
205 Default values are 'magenta', 'default'.
206 colors.root::
207 Colors for headers in the output of a sub-commands (top, report).
208 Default values are 'white', 'blue'.
210 core.*::
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.
216 tui.*, gtk.*::
217 Subcommands that can be configured here are 'top', 'report' and 'annotate'.
218 These values are booleans, for example:
220 [tui]
221 top = true
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.
226 buildid.*::
227 buildid.dir::
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
241 annotate.*::
242 These options work only for TUI.
243 These are in control of addresses, jump function, source code
244 in lines of assembly code from a specific program.
246 annotate.hide_src_code::
247 If a program which is analyzed has source code,
248 this option lets 'annotate' print a list of assembly code with the source code.
249 For example, let's see a part of a program. There're four lines.
250 If this option is 'true', they can be printed
251 without source code from a program as below.
253 │ push %rbp
254 │ mov %rsp,%rbp
255 │ sub $0x10,%rsp
256 │ mov (%rdi),%rdx
258 But if this option is 'false', source code of the part
259 can be also printed as below. Default is 'false'.
261 │ struct rb_node *rb_next(const struct rb_node *node)
262 │ {
263 │ push %rbp
264 │ mov %rsp,%rbp
265 │ sub $0x10,%rsp
266 │ struct rb_node *parent;
267 │
268 │ if (RB_EMPTY_NODE(node))
269 │ mov (%rdi),%rdx
270 │ return n;
272 annotate.use_offset::
273 Basing on a first address of a loaded function, offset can be used.
274 Instead of using original addresses of assembly code,
275 addresses subtracted from a base address can be printed.
276 Let's illustrate an example.
277 If a base address is 0XFFFFFFFF81624d50 as below,
279 ffffffff81624d50 <load0>
281 an address on assembly code has a specific absolute address as below
283 ffffffff816250b8:│ mov 0x8(%r14),%rdi
285 but if use_offset is 'true', an address subtracted from a base address is printed.
286 Default is true. This option is only applied to TUI.
288 368:│ mov 0x8(%r14),%rdi
290 annotate.jump_arrows::
291 There can be jump instruction among assembly code.
292 Depending on a boolean value of jump_arrows,
293 arrows can be printed or not which represent
294 where do the instruction jump into as below.
296 │ ┌──jmp 1333
297 │ │ xchg %ax,%ax
298 │1330:│ mov %r15,%r10
299 │1333:└─→cmp %r15,%r14
301 If jump_arrow is 'false', the arrows isn't printed as below.
302 Default is 'false'.
304 │ ↓ jmp 1333
305 │ xchg %ax,%ax
306 │1330: mov %r15,%r10
307 │1333: cmp %r15,%r14
309 annotate.show_linenr::
310 When showing source code if this option is 'true',
311 line numbers are printed as below.
313 │1628 if (type & PERF_SAMPLE_IDENTIFIER) {
314 │ ↓ jne 508
315 │1628 data->id = *array;
316 │1629 array++;
317 │1630 }
319 However if this option is 'false', they aren't printed as below.
320 Default is 'false'.
322 │ if (type & PERF_SAMPLE_IDENTIFIER) {
323 │ ↓ jne 508
324 │ data->id = *array;
325 │ array++;
326 │ }
328 annotate.show_nr_jumps::
329 Let's see a part of assembly code.
331 │1382: movb $0x1,-0x270(%rbp)
333 If use this, the number of branches jumping to that address can be printed as below.
334 Default is 'false'.
336 │1 1382: movb $0x1,-0x270(%rbp)
338 annotate.show_total_period::
339 To compare two records on an instruction base, with this option
340 provided, display total number of samples that belong to a line
341 in assembly code. If this option is 'true', total periods are printed
342 instead of percent values as below.
344 302 │ mov %eax,%eax
346 But if this option is 'false', percent values for overhead are printed i.e.
347 Default is 'false'.
349 99.93 │ mov %eax,%eax
351 annotate.offset_level::
352 Default is '1', meaning just jump targets will have offsets show right beside
353 the instruction. When set to '2' 'call' instructions will also have its offsets
354 shown, 3 or higher will show offsets for all instructions.
356 hist.*::
357 hist.percentage::
358 This option control the way to calculate overhead of filtered entries -
359 that means the value of this option is effective only if there's a
360 filter (by comm, dso or symbol name). Suppose a following example:
362 Overhead Symbols
363 ........ .......
364 33.33% foo
365 33.33% bar
366 33.33% baz
368 This is an original overhead and we'll filter out the first 'foo'
369 entry. The value of 'relative' would increase the overhead of 'bar'
370 and 'baz' to 50.00% for each, while 'absolute' would show their
371 current overhead (33.33%).
373 ui.*::
374 ui.show-headers::
375 This option controls display of column headers (like 'Overhead' and 'Symbol')
376 in 'report' and 'top'. If this option is false, they are hidden.
377 This option is only applied to TUI.
379 call-graph.*::
380 When sub-commands 'top' and 'report' work with -g/—-children
381 there're options in control of call-graph.
383 call-graph.record-mode::
384 The record-mode can be 'fp' (frame pointer), 'dwarf' and 'lbr'.
385 The value of 'dwarf' is effective only if perf detect needed library
386 (libunwind or a recent version of libdw).
387 'lbr' only work for cpus that support it.
389 call-graph.dump-size::
390 The size of stack to dump in order to do post-unwinding. Default is 8192 (byte).
391 When using dwarf into record-mode, the default size will be used if omitted.
393 call-graph.print-type::
394 The print-types can be graph (graph absolute), fractal (graph relative),
395 flat and folded. This option controls a way to show overhead for each callchain
396 entry. Suppose a following example.
398 Overhead Symbols
399 ........ .......
400 40.00% foo
401 |
402 ---foo
403 |
404 |--50.00%--bar
405 | main
406 |
407 --50.00%--baz
408 main
410 This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
411 half and half so 'fractal' shows 50.00% for each
412 (meaning that it assumes 100% total overhead of 'foo').
414 The 'graph' uses absolute overhead value of 'foo' as total so each of
415 'bar' and 'baz' callchain will have 20.00% of overhead.
416 If 'flat' is used, single column and linear exposure of call chains.
417 'folded' mean call chains are displayed in a line, separated by semicolons.
419 call-graph.order::
420 This option controls print order of callchains. The default is
421 'callee' which means callee is printed at top and then followed by its
422 caller and so on. The 'caller' prints it in reverse order.
424 If this option is not set and report.children or top.children is
425 set to true (or the equivalent command line option is given),
426 the default value of this option is changed to 'caller' for the
427 execution of 'perf report' or 'perf top'. Other commands will
428 still default to 'callee'.
430 call-graph.sort-key::
431 The callchains are merged if they contain same information.
432 The sort-key option determines a way to compare the callchains.
433 A value of 'sort-key' can be 'function' or 'address'.
434 The default is 'function'.
436 call-graph.threshold::
437 When there're many callchains it'd print tons of lines. So perf omits
438 small callchains under a certain overhead (threshold) and this option
439 control the threshold. Default is 0.5 (%). The overhead is calculated
440 by value depends on call-graph.print-type.
442 call-graph.print-limit::
443 This is a maximum number of lines of callchain printed for a single
444 histogram entry. Default is 0 which means no limitation.
446 report.*::
447 report.sort_order::
448 Allows changing the default sort order from "comm,dso,symbol" to
449 some other default, for instance "sym,dso" may be more fitting for
450 kernel developers.
451 report.percent-limit::
452 This one is mostly the same as call-graph.threshold but works for
453 histogram entries. Entries having an overhead lower than this
454 percentage will not be printed. Default is '0'. If percent-limit
455 is '10', only entries which have more than 10% of overhead will be
456 printed.
458 report.queue-size::
459 This option sets up the maximum allocation size of the internal
460 event queue for ordering events. Default is 0, meaning no limit.
462 report.children::
463 'Children' means functions called from another function.
464 If this option is true, 'perf report' cumulates callchains of children
465 and show (accumulated) total overhead as well as 'Self' overhead.
466 Please refer to the 'perf report' manual. The default is 'true'.
468 report.group::
469 This option is to show event group information together.
470 Example output with this turned on, notice that there is one column
471 per event in the group, ref-cycles and cycles:
473 # group: {ref-cycles,cycles}
474 # ========
475 #
476 # Samples: 7K of event 'anon group { ref-cycles, cycles }'
477 # Event count (approx.): 6876107743
478 #
479 # Overhead Command Shared Object Symbol
480 # ................ ....... ................. ...................
481 #
482 99.84% 99.76% noploop noploop [.] main
483 0.07% 0.00% noploop ld-2.15.so [.] strcmp
484 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
486 top.*::
487 top.children::
488 Same as 'report.children'. So if it is enabled, the output of 'top'
489 command will have 'Children' overhead column as well as 'Self' overhead
490 column by default.
491 The default is 'true'.
493 man.*::
494 man.viewer::
495 This option can assign a tool to view manual pages when 'help'
496 subcommand was invoked. Supported tools are 'man', 'woman'
497 (with emacs client) and 'konqueror'. Default is 'man'.
499 New man viewer tool can be also added using 'man.<tool>.cmd'
500 or use different path using 'man.<tool>.path' config option.
502 pager.*::
503 pager.<subcommand>::
504 When the subcommand is run on stdio, determine whether it uses
505 pager or not based on this value. Default is 'unspecified'.
507 kmem.*::
508 kmem.default::
509 This option decides which allocator is to be analyzed if neither
510 '--slab' nor '--page' option is used. Default is 'slab'.
512 record.*::
513 record.build-id::
514 This option can be 'cache', 'no-cache' or 'skip'.
515 'cache' is to post-process data and save/update the binaries into
516 the build-id cache (in ~/.debug). This is the default.
517 But if this option is 'no-cache', it will not update the build-id cache.
518 'skip' skips post-processing and does not update the cache.
520 diff.*::
521 diff.order::
522 This option sets the number of columns to sort the result.
523 The default is 0, which means sorting by baseline.
524 Setting it to 1 will sort the result by delta (or other
525 compute method selected).
527 diff.compute::
528 This options sets the method for computing the diff result.
529 Possible values are 'delta', 'delta-abs', 'ratio' and
530 'wdiff'. Default is 'delta'.
532 trace.*::
533 trace.add_events::
534 Allows adding a set of events to add to the ones specified
535 by the user, or use as a default one if none was specified.
536 The initial use case is to add augmented_raw_syscalls.o to
537 activate the 'perf trace' logic that looks for syscall
538 pointer contents after the normal tracepoint payload.
540 trace.args_alignment::
541 Number of columns to align the argument list, default is 70,
542 use 40 for the strace default, zero to no alignment.
544 trace.no_inherit::
545 Do not follow children threads.
547 trace.show_arg_names::
548 Should syscall argument names be printed? If not then trace.show_zeros
549 will be set.
551 trace.show_duration::
552 Show syscall duration.
554 trace.show_prefix::
555 If set to 'yes' will show common string prefixes in tables. The default
556 is to remove the common prefix in things like "MAP_SHARED", showing just "SHARED".
558 trace.show_timestamp::
559 Show syscall start timestamp.
561 trace.show_zeros::
562 Do not suppress syscall arguments that are equal to zero.
564 trace.tracepoint_beautifiers::
565 Use "libtraceevent" to use that library to augment the tracepoint arguments,
566 "libbeauty", the default, to use the same argument beautifiers used in the
567 strace-like sys_enter+sys_exit lines.
569 llvm.*::
570 llvm.clang-path::
571 Path to clang. If omit, search it from $PATH.
573 llvm.clang-bpf-cmd-template::
574 Cmdline template. Below lines show its default value. Environment
575 variable is used to pass options.
576 "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
577 "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
578 "$CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS " \
579 "-Wno-unused-value -Wno-pointer-sign " \
580 "-working-directory $WORKING_DIR " \
581 "-c \"$CLANG_SOURCE\" -target bpf $CLANG_EMIT_LLVM -O2 -o - $LLVM_OPTIONS_PIPE"
583 llvm.clang-opt::
584 Options passed to clang.
586 llvm.kbuild-dir::
587 kbuild directory. If not set, use /lib/modules/`uname -r`/build.
588 If set to "" deliberately, skip kernel header auto-detector.
590 llvm.kbuild-opts::
591 Options passed to 'make' when detecting kernel header options.
593 llvm.dump-obj::
594 Enable perf dump BPF object files compiled by LLVM.
596 llvm.opts::
597 Options passed to llc.
599 samples.*::
601 samples.context::
602 Define how many ns worth of time to show
603 around samples in perf report sample context browser.
605 scripts.*::
607 Any option defines a script that is added to the scripts menu
608 in the interactive perf browser and whose output is displayed.
609 The name of the option is the name, the value is a script command line.
610 The script gets the same options passed as a full perf script,
611 in particular -i perfdata file, --cpu, --tid
613 SEE ALSO
614 --------
615 linkperf:perf[1]