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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /tools/perf/Documentation/perf-config.txt | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/Documentation/perf-config.txt')
-rw-r--r-- | tools/perf/Documentation/perf-config.txt | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt new file mode 100644 index 000000000..05c10eb56 --- /dev/null +++ b/tools/perf/Documentation/perf-config.txt @@ -0,0 +1,520 @@ +perf-config(1) +============== + +NAME +---- +perf-config - Get and set variables in a configuration file. + +SYNOPSIS +-------- +[verse] +'perf config' [<file-option>] [section.name[=value] ...] +or +'perf config' [<file-option>] -l | --list + +DESCRIPTION +----------- +You can manage variables in a configuration file with this command. + +OPTIONS +------- + +-l:: +--list:: + Show current config variables, name and value, for all sections. + +--user:: + For writing and reading options: write to user + '$HOME/.perfconfig' file or read it. + +--system:: + For writing and reading options: write to system-wide + '$(sysconfdir)/perfconfig' or read it. + +CONFIGURATION FILE +------------------ + +The perf configuration file contains many variables to change various +aspects of each of its tools, including output, disk usage, etc. +The '$HOME/.perfconfig' file is used to store a per-user configuration. +The file '$(sysconfdir)/perfconfig' can be used to +store a system-wide default configuration. + +When reading or writing, the values are read from the system and user +configuration files by default, and options '--system' and '--user' +can be used to tell the command to read from or write to only that location. + +Syntax +~~~~~~ + +The file consist of sections. A section starts with its name +surrounded by square brackets and continues till the next section +begins. Each variable must be in a section, and have the form +'name = value', for example: + + [section] + name1 = value1 + name2 = value2 + +Section names are case sensitive and can contain any characters except +newline (double quote `"` and backslash have to be escaped as `\"` and `\\`, +respectively). Section headers can't span multiple lines. + +Example +~~~~~~~ + +Given a $HOME/.perfconfig like this: + +# +# This is the config file, and +# a '#' and ';' character indicates a comment +# + + [colors] + # Color variables + top = red, default + medium = green, default + normal = lightgray, default + selected = white, lightgray + jump_arrows = blue, default + addr = magenta, default + root = white, blue + + [tui] + # Defaults if linked with libslang + report = on + annotate = on + top = on + + [buildid] + # Default, disable using /dev/null + dir = ~/.debug + + [annotate] + # Defaults + hide_src_code = false + use_offset = true + jump_arrows = true + show_nr_jumps = false + + [help] + # Format can be man, info, web or html + format = man + autocorrect = 0 + + [ui] + show-headers = true + + [call-graph] + # fp (framepointer), dwarf + record-mode = fp + print-type = graph + order = caller + sort-key = function + + [report] + # Defaults + sort_order = comm,dso,symbol + percent-limit = 0 + queue-size = 0 + children = true + group = true + +You can hide source code of annotate feature setting the config to false with + + % perf config annotate.hide_src_code=true + +If you want to add or modify several config items, you can do like + + % perf config ui.show-headers=false kmem.default=slab + +To modify the sort order of report functionality in user config file(i.e. `~/.perfconfig`), do + + % perf config --user report sort-order=srcline + +To change colors of selected line to other foreground and background colors +in system config file (i.e. `$(sysconf)/perfconfig`), do + + % perf config --system colors.selected=yellow,green + +To query the record mode of call graph, do + + % perf config call-graph.record-mode + +If you want to know multiple config key/value pairs, you can do like + + % perf config report.queue-size call-graph.order report.children + +To query the config value of sort order of call graph in user config file (i.e. `~/.perfconfig`), do + + % perf config --user call-graph.sort-order + +To query the config value of buildid directory in system config file (i.e. `$(sysconf)/perfconfig`), do + + % perf config --system buildid.dir + +Variables +~~~~~~~~~ + +colors.*:: + The variables for customizing the colors used in the output for the + 'report', 'top' and 'annotate' in the TUI. They should specify the + foreground and background colors, separated by a comma, for example: + + medium = green, lightgray + + If you want to use the color configured for you terminal, just leave it + as 'default', for example: + + medium = default, lightgray + + Available colors: + red, yellow, green, cyan, gray, black, blue, + white, default, magenta, lightgray + + colors.top:: + 'top' means a overhead percentage which is more than 5%. + And values of this variable specify percentage colors. + Basic key values are foreground-color 'red' and + background-color 'default'. + colors.medium:: + 'medium' means a overhead percentage which has more than 0.5%. + Default values are 'green' and 'default'. + colors.normal:: + 'normal' means the rest of overhead percentages + except 'top', 'medium', 'selected'. + Default values are 'lightgray' and 'default'. + colors.selected:: + This selects the colors for the current entry in a list of entries + from sub-commands (top, report, annotate). + Default values are 'black' and 'lightgray'. + colors.jump_arrows:: + Colors for jump arrows on assembly code listings + such as 'jns', 'jmp', 'jane', etc. + Default values are 'blue', 'default'. + colors.addr:: + This selects colors for addresses from 'annotate'. + Default values are 'magenta', 'default'. + colors.root:: + Colors for headers in the output of a sub-commands (top, report). + Default values are 'white', 'blue'. + +tui.*, gtk.*:: + Subcommands that can be configured here are 'top', 'report' and 'annotate'. + These values are booleans, for example: + + [tui] + top = true + + will make the TUI be the default for the 'top' subcommand. Those will be + available if the required libs were detected at tool build time. + +buildid.*:: + buildid.dir:: + Each executable and shared library in modern distributions comes with a + content based identifier that, if available, will be inserted in a + 'perf.data' file header to, at analysis time find what is needed to do + symbol resolution, code annotation, etc. + + The recording tools also stores a hard link or copy in a per-user + directory, $HOME/.debug/, of binaries, shared libraries, /proc/kallsyms + and /proc/kcore files to be used at analysis time. + + The buildid.dir variable can be used to either change this directory + cache location, or to disable it altogether. If you want to disable it, + set buildid.dir to /dev/null. The default is $HOME/.debug + +annotate.*:: + These options work only for TUI. + These are in control of addresses, jump function, source code + in lines of assembly code from a specific program. + + annotate.hide_src_code:: + If a program which is analyzed has source code, + this option lets 'annotate' print a list of assembly code with the source code. + For example, let's see a part of a program. There're four lines. + If this option is 'true', they can be printed + without source code from a program as below. + + │ push %rbp + │ mov %rsp,%rbp + │ sub $0x10,%rsp + │ mov (%rdi),%rdx + + But if this option is 'false', source code of the part + can be also printed as below. Default is 'false'. + + │ struct rb_node *rb_next(const struct rb_node *node) + │ { + │ push %rbp + │ mov %rsp,%rbp + │ sub $0x10,%rsp + │ struct rb_node *parent; + │ + │ if (RB_EMPTY_NODE(node)) + │ mov (%rdi),%rdx + │ return n; + + annotate.use_offset:: + Basing on a first address of a loaded function, offset can be used. + Instead of using original addresses of assembly code, + addresses subtracted from a base address can be printed. + Let's illustrate an example. + If a base address is 0XFFFFFFFF81624d50 as below, + + ffffffff81624d50 <load0> + + an address on assembly code has a specific absolute address as below + + ffffffff816250b8:│ mov 0x8(%r14),%rdi + + but if use_offset is 'true', an address subtracted from a base address is printed. + Default is true. This option is only applied to TUI. + + 368:│ mov 0x8(%r14),%rdi + + annotate.jump_arrows:: + There can be jump instruction among assembly code. + Depending on a boolean value of jump_arrows, + arrows can be printed or not which represent + where do the instruction jump into as below. + + │ ┌──jmp 1333 + │ │ xchg %ax,%ax + │1330:│ mov %r15,%r10 + │1333:└─→cmp %r15,%r14 + + If jump_arrow is 'false', the arrows isn't printed as below. + Default is 'false'. + + │ ↓ jmp 1333 + │ xchg %ax,%ax + │1330: mov %r15,%r10 + │1333: cmp %r15,%r14 + + annotate.show_linenr:: + When showing source code if this option is 'true', + line numbers are printed as below. + + │1628 if (type & PERF_SAMPLE_IDENTIFIER) { + │ ↓ jne 508 + │1628 data->id = *array; + │1629 array++; + │1630 } + + However if this option is 'false', they aren't printed as below. + Default is 'false'. + + │ if (type & PERF_SAMPLE_IDENTIFIER) { + │ ↓ jne 508 + │ data->id = *array; + │ array++; + │ } + + annotate.show_nr_jumps:: + Let's see a part of assembly code. + + │1382: movb $0x1,-0x270(%rbp) + + If use this, the number of branches jumping to that address can be printed as below. + Default is 'false'. + + │1 1382: movb $0x1,-0x270(%rbp) + + annotate.show_total_period:: + To compare two records on an instruction base, with this option + provided, display total number of samples that belong to a line + in assembly code. If this option is 'true', total periods are printed + instead of percent values as below. + + 302 │ mov %eax,%eax + + But if this option is 'false', percent values for overhead are printed i.e. + Default is 'false'. + + 99.93 │ mov %eax,%eax + + annotate.offset_level:: + Default is '1', meaning just jump targets will have offsets show right beside + the instruction. When set to '2' 'call' instructions will also have its offsets + shown, 3 or higher will show offsets for all instructions. + +hist.*:: + hist.percentage:: + This option control the way to calculate overhead of filtered entries - + that means the value of this option is effective only if there's a + filter (by comm, dso or symbol name). Suppose a following example: + + Overhead Symbols + ........ ....... + 33.33% foo + 33.33% bar + 33.33% baz + + This is an original overhead and we'll filter out the first 'foo' + entry. The value of 'relative' would increase the overhead of 'bar' + and 'baz' to 50.00% for each, while 'absolute' would show their + current overhead (33.33%). + +ui.*:: + ui.show-headers:: + This option controls display of column headers (like 'Overhead' and 'Symbol') + in 'report' and 'top'. If this option is false, they are hidden. + This option is only applied to TUI. + +call-graph.*:: + When sub-commands 'top' and 'report' work with -g/—-children + there're options in control of call-graph. + + call-graph.record-mode:: + The record-mode can be 'fp' (frame pointer), 'dwarf' and 'lbr'. + The value of 'dwarf' is effective only if perf detect needed library + (libunwind or a recent version of libdw). + 'lbr' only work for cpus that support it. + + call-graph.dump-size:: + The size of stack to dump in order to do post-unwinding. Default is 8192 (byte). + When using dwarf into record-mode, the default size will be used if omitted. + + call-graph.print-type:: + The print-types can be graph (graph absolute), fractal (graph relative), + flat and folded. This option controls a way to show overhead for each callchain + entry. Suppose a following example. + + Overhead Symbols + ........ ....... + 40.00% foo + | + ---foo + | + |--50.00%--bar + | main + | + --50.00%--baz + main + + This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly + half and half so 'fractal' shows 50.00% for each + (meaning that it assumes 100% total overhead of 'foo'). + + The 'graph' uses absolute overhead value of 'foo' as total so each of + 'bar' and 'baz' callchain will have 20.00% of overhead. + If 'flat' is used, single column and linear exposure of call chains. + 'folded' mean call chains are displayed in a line, separated by semicolons. + + call-graph.order:: + This option controls print order of callchains. The default is + 'callee' which means callee is printed at top and then followed by its + caller and so on. The 'caller' prints it in reverse order. + + If this option is not set and report.children or top.children is + set to true (or the equivalent command line option is given), + the default value of this option is changed to 'caller' for the + execution of 'perf report' or 'perf top'. Other commands will + still default to 'callee'. + + call-graph.sort-key:: + The callchains are merged if they contain same information. + The sort-key option determines a way to compare the callchains. + A value of 'sort-key' can be 'function' or 'address'. + The default is 'function'. + + call-graph.threshold:: + When there're many callchains it'd print tons of lines. So perf omits + small callchains under a certain overhead (threshold) and this option + control the threshold. Default is 0.5 (%). The overhead is calculated + by value depends on call-graph.print-type. + + call-graph.print-limit:: + This is a maximum number of lines of callchain printed for a single + histogram entry. Default is 0 which means no limitation. + +report.*:: + report.sort_order:: + Allows changing the default sort order from "comm,dso,symbol" to + some other default, for instance "sym,dso" may be more fitting for + kernel developers. + report.percent-limit:: + This one is mostly the same as call-graph.threshold but works for + histogram entries. Entries having an overhead lower than this + percentage will not be printed. Default is '0'. If percent-limit + is '10', only entries which have more than 10% of overhead will be + printed. + + report.queue-size:: + This option sets up the maximum allocation size of the internal + event queue for ordering events. Default is 0, meaning no limit. + + report.children:: + 'Children' means functions called from another function. + If this option is true, 'perf report' cumulates callchains of children + and show (accumulated) total overhead as well as 'Self' overhead. + Please refer to the 'perf report' manual. The default is 'true'. + + report.group:: + This option is to show event group information together. + Example output with this turned on, notice that there is one column + per event in the group, ref-cycles and cycles: + + # group: {ref-cycles,cycles} + # ======== + # + # Samples: 7K of event 'anon group { ref-cycles, cycles }' + # Event count (approx.): 6876107743 + # + # Overhead Command Shared Object Symbol + # ................ ....... ................. ................... + # + 99.84% 99.76% noploop noploop [.] main + 0.07% 0.00% noploop ld-2.15.so [.] strcmp + 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del + +top.*:: + top.children:: + Same as 'report.children'. So if it is enabled, the output of 'top' + command will have 'Children' overhead column as well as 'Self' overhead + column by default. + The default is 'true'. + +man.*:: + man.viewer:: + This option can assign a tool to view manual pages when 'help' + subcommand was invoked. Supported tools are 'man', 'woman' + (with emacs client) and 'konqueror'. Default is 'man'. + + New man viewer tool can be also added using 'man.<tool>.cmd' + or use different path using 'man.<tool>.path' config option. + +pager.*:: + pager.<subcommand>:: + When the subcommand is run on stdio, determine whether it uses + pager or not based on this value. Default is 'unspecified'. + +kmem.*:: + kmem.default:: + This option decides which allocator is to be analyzed if neither + '--slab' nor '--page' option is used. Default is 'slab'. + +record.*:: + record.build-id:: + This option can be 'cache', 'no-cache' or 'skip'. + 'cache' is to post-process data and save/update the binaries into + the build-id cache (in ~/.debug). This is the default. + But if this option is 'no-cache', it will not update the build-id cache. + 'skip' skips post-processing and does not update the cache. + +diff.*:: + diff.order:: + This option sets the number of columns to sort the result. + The default is 0, which means sorting by baseline. + Setting it to 1 will sort the result by delta (or other + compute method selected). + + diff.compute:: + This options sets the method for computing the diff result. + Possible values are 'delta', 'delta-abs', 'ratio' and + 'wdiff'. Default is 'delta'. + +SEE ALSO +-------- +linkperf:perf[1] |