Re: [PATCH v6 1/7] perf tools: Add 'perf-config' command

From: Arnaldo Carvalho de Melo
Date: Mon Sep 28 2015 - 10:01:57 EST

Em Wed, Sep 23, 2015 at 03:57:01PM +0900, Taeung Song escreveu:
> The perf configuration file contains many variables which can make
> the perf command's action more effective.
> But looking through state of configuration is difficult and there's no knowing
> what kind of other variables except variables in perfconfig.example exist.
> So This patch adds 'perf-config' command with '--list' option and a document for it.
>
> perf config [options]
>
> display current perf config variables.
> # perf config
> or
> # perf config -l | --list
>
> Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
> ---
> tools/perf/Build | 1 +
> tools/perf/Documentation/perf-config.txt | 381 +++++++++++++++++++++++++++++++
> tools/perf/builtin-config.c | 62 +++++
> tools/perf/builtin.h | 1 +
> tools/perf/command-list.txt | 1 +
> tools/perf/perf.c | 1 +
> 6 files changed, 447 insertions(+)
> create mode 100644 tools/perf/Documentation/perf-config.txt
> create mode 100644 tools/perf/builtin-config.c
>
> diff --git a/tools/perf/Build b/tools/perf/Build
> index 7223745..2c7aaf2 100644
> --- a/tools/perf/Build
> +++ b/tools/perf/Build
> @@ -1,5 +1,6 @@
> perf-y += builtin-bench.o
> perf-y += builtin-annotate.o
> +perf-y += builtin-config.o
> perf-y += builtin-diff.o
> perf-y += builtin-evlist.o
> perf-y += builtin-help.o
> diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
> new file mode 100644
> index 0000000..a3a12cc
> --- /dev/null
> +++ b/tools/perf/Documentation/perf-config.txt
> @@ -0,0 +1,381 @@
> +perf-config(1)
> +==============
> +
> +NAME
> +----
> +perf-config - Get and set variables in a configuration file.
> +
> +SYNOPSIS
> +--------
> +[verse]
> +'perf config' -l | --list
> +
> +DESCRIPTION
> +-----------
> +You can manage variables in a configuration file with this command.
> +
> +OPTIONS
> +-------
> +
> +-l::
> +--list::
> + Show current config variables with key and value into each sections.

Show current config variables, name and value, for all sections.

> +
> +CONFIGURATION FILE
> +------------------
> +
> +The Perf configuration file contains many variables which can make
> +the perf command's action more effective.
> +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.
> +
> +The variables are divided into sections. In each section, the variables
> +can are composed of a key and value.

"can are" -> "that are"

> +
> +Syntax
> +~~~~~~
> +
> +The file consists of sections and names. A section begins with
> +the name of the section in square brackets and continues until the next

The file consists of sections. A section startas with its name
surrounded by square brackers and continues till the next section
begins.

> +section begins. Each variable have to belong to some section, which means
> +there must be a section header before the first setting of a variable, as below:

Each variable belongs to a section, which means that there must be a
section header before the first variable, as below:

> +Each variable are in the form 'name = value'.
> +
> + [section]
> + name1 = value1
> + name2 = value2
> +
> +Section names are case sensitive and can contain any characters except
> +newline (doublequote `"` and backslash have to be escaped as `\"` and `\\`,

double quote

> +respectively). Section headers can't span multiple
> +lines. Variables may belong directly to a section.

? They "may" or they "must"? what means "belong directly to a section"?

> +
> +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
> + code = 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
> +
> +Variables
> +~~~~~~~~~
> +
> +colors.*::
> + Color variables can customize colors of the output which is printed out
> + from âreportâ, âtopâ, âannotateâ on tui.
> + Color variables are composed of foreground and background
> + and should have two values for them. If you want to keep as colors

"and should have two values, comma separated. (please provide an example
of setting one of those variables).

> + of your terminal, you should use âdefaultâ for the color value.

If you want to keep the background or the foreground color set for your
terminal, replace the desired value with 'default'. For instance:

(provide an example of setting just the foreground or the background,
with 'default' for the terminal color that should be used

> + The color names that can be used are:

Shorter:

"Avaliable colors:"

> + red, green, default, black, blue, white, magenta, lightgray
> +
> + colors.top::
> + âtopâ means a overhead percentage which is more than 5%.
> + And values of this variable specify colors of percentage.
> + Basic key values are foreground-color âredâ and
> + background-color âdefaultâ.
> + colors.medium::
> + âmediumâ means a overhead percentage which has more than 0.5%.
> + Default values are âgreenâ and âdefaultâ.
> + colors.normal::
> + ânormalâ means the rest of overhead percentages
> + except âtopâ, âmediumâ, âselectedâ.
> + Default values are âlightgrayâ and âdefaultâ.
> + colors.selected::
> + This selects the colors for the current entry in a list of entries
> + from sub-commands (top,report,annotate).
> + Default values are âwhiteâ and âlightgrayâ.
> + colors.code::
> + Colors for arrows and lines in jumps on assembly code listings
> + such as âjnsâ,âjmpâ,âjaneâ,etc. Default values are âblueâ, âdefaultâ.
> + colors.addr::
> + This selects colors for addresses from âannotateâ.
> + Default values are âmagentaâ, âdefaultâ.
> + colors.root::
> + Colors for headers in the output of a sub-command âtopâ.
> + Default values are âwhiteâ, âblueâ.
> +
> +tui.*::
> + A boolean value that controls launching TUI browser for each subcommand.

A boolean value that controls if the TUI browser will be used
for subcomands having that UI.

> + By default, TUI is enabled if perf detects the required library during build
> + and this config option can control it. Available subcommands are 'top',
> + 'report' and 'annotate'.
> +
> +gtk.*::
> + A boolean value that controls launching GTK+2 GUI browser for
> + each subcommand. By default, TUI is enabled if perf detects the

Use TUI wording suggested above

> + required library during build and this config option can control it.
> + Available subcommands are 'top', 'report' and 'annotate'.
> +
> +buildid.*::
> + buildid.dir::
> + Each executable or shared library built with each program is assigned
> + a unique identification as build-id. The option means a path where
> + build-id information can be saved.

Each executable and shared library in modern distributions comes with a
content based identified 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 anotation, 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.

---
find out how to disable it, iirc, its a matter of testing if setting
buildid.dir to /dev/null works
Yeah, it works:

[acme@zoo linux]$ ls -la ~/.debug/
ls: cannot access /home/acme/.debug/: No such file or directory
[acme@zoo linux]$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ]
[acme@zoo linux]$ ls -la ~/.debug/
ls: cannot access /home/acme/.debug/: No such file or directory
[acme@zoo linux]$ cat ~/.perfconfig
[buildid]
dir = /dev/null
[acme@zoo linux]$

> + The default is $HOME/.debug
> +
> +annotate.*::
> + Thereâre options which work with a âannotateâ sub-command.
> + This options is 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 of itself,

No need for "of itself"

> + this option let âannotateâ print a list of assembly code with the source code.
lets to print

Getting sidetracked, hope this helps.

- Arnaldo

> + For example, letâs see a part of a program. Thereâre four lines.
> + If this option is âfalseâ, they can be printed
> + without source code from a program as below.
> +
> + â push %rbp
> + â mov %rsp,%rbp
> + â sub $0x10,%rsp
> + â mov (%rdi),%rdx
> +
> + But if this option is âtrueâ, source code of the part
> + can be also printed as below.
> +
> + â struct rb_node *rb_next(const struct rb_node *node)
> + â {
> + â push %rbp
> + â mov %rsp,%rbp
> + â sub $0x10,%rsp
> + â struct rb_node *parent;
> + â
> + â if (RB_EMPTY_NODE(node))
> + â mov (%rdi),%rdx
> + â 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.
> + Letâs illustrate a example.
> + If a base address is 0XFFFFFFFF81624d50 as below,
> +
> + ffffffff81624d50 <load0>
> +
> + a address on assembly code has a specific absolute address as below
> +
> + ffffffff816250b8:â mov 0x8(%r14),%rdi
> +
> + but if use_offset is âtrueâ, a address subtracted from a base address is printed.
> + The default is true.
> +
> + 368:â mov 0x8(%r14),%rdi
> +
> + annotate.jump_arrows::
> + Thereâre 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.
> +
> + â âââjmp 1333
> + â â xchg %ax,%ax
> + â1330:â mov %r15,%r10
> + â1333:âââcmp %r15,%r14
> +
> + If jump_arrow is âfalseâ, the arrows isnât printed as below.
> +
> + â â jmp 1333
> + â xchg %ax,%ax
> + â1330: mov %r15,%r10
> + â1333: cmp %r15,%r14
> +
> + annotate.show_nr_jumps::
> + Letâs see a part of assembly code.
> +
> + â1382: movb $0x1,-0x270(%rbp)
> +
> + If use this, the number of branches branching to that address can be printed as below.
> +
> + â1 1382: movb $0x1,-0x270(%rbp)
> +
> +help.*::
> + help.format:: = man
> + A format of manual page can be âmanâ, âinfoâ, âwebâ or âhtmlâ.
> + âmanâ is default.
> + help.autocorrect:: = 0
> + Automatically correct and execute mistyped commands after
> + waiting for the given number of deciseconds (0.1 sec).
> + Let's see a example. If a mistyped sub-command is executed like 'perf mistyped-command'
> + and this option is 0, the output is as below.
> +
> + perf: 'mistyped-command' is not a perf-command. See 'perf --helpâ.
> +
> + Or if this option is more than 1, the output can be such as.
> +
> + WARNING: You called a perf program named 'mistyped-command', which does not exist.
> + Continuing under the assumption that you meant 'with-kcore'
> + in 0.1 seconds automatically...
> + Usage: perf-with-kcore <perf sub-command> <perf.data directory> [<sub-command options> [ -- <workload>]]
> + <perf sub-command> can be record, script, report or inject
> + or: perf-with-kcore fix_buildid_cache_permissions
> +
> +hist.*::
> + hist.percentage::
> + This option control a way to calcurate 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::
> + Thereâre columns as header âOverheadâ, âChildrenâ, âShared Objectâ, âSymbolâ, âselfâ.
> + If this option is false, they are hiden.
> +
> +call-graph.*::
> + When sub-commands âtopâ and âreportâ work with -g/â-children
> + thereâre options in control of call-graph.
> +
> + call-graph.record-mode::
> + The record-mode can be âfpâ (frame pointer) and âdwarfâ.
> + The value of 'dwarf' is effective only if perf detect needed library
> + (libunwind or a recent version of libdw). Also it doesn't *require*
> + the dump-size option since it can use the default value of 8192 if
> + missing.
> +
> + 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 this option should have a value.
> +
> + call-graph.print-type::
> + The print-types can be graph (graph absolute), fractal (graph relative), flat.
> + 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 default format which is 'fractal'. 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.
> +
> + 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.
> +
> + 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 'addressâ.
> + The default is âfunctionâ.
> +
> + 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 threashold. Default is 0.5 (%).
> +
> + call-graph.print-limit::
> + This is another way to control the number of callchains printed for a
> + single entry. Default is 0 which means no limitation.
> +
> +report.*::
> + report.percent-limit::
> + This one is mostly same as call-graph.threshold but works for
> + histogram entries. Entries have overhead lower than this percentage
> + will not be printed. Default is 0.
> + If percent-limit is 70, the output which has percentages of
> + each overhead above 70% can be printed.
> +
> + report.queue-size::
> + option to setup the maximum allocation size for session's
> + ordered events queue, if not set there's no default limit.
> +
> + report.children::
> + The children means that functions called from another function.
> + If the option is true, accumulate callchain of children and show total overhead.
> + Please refer to the perf-report manual.
> +
> +top.*::
> + top.children::
> + This option means same as report.children.
> + So it is true, the output of âtopâ is rearranged by each overhead into children group.
> +
> +man.*::
> + man.viewer::
> + This option can assign a manual tool with which a subcommand 'help' work.
> + it can used as 'man', 'woman', 'konqueror'. Default value is 'man'.
> +
> +pager.*::
> + pager.<subcommand>::
> + When a subcommand work as stdio instead of TUI, use pager with it.
> + Default value is 'true'.
> +
> +kmem.*::
> + kmem.default::
> + This option can decide which allocator is analyzed between 'slab' and 'page'
> + without using options '--slab' and '--page'.
> + Default value is 'slab'.
> +
> +SEE ALSO
> +--------
> +linkperf:perf[1], linkperf:perf-report[1]
> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
> new file mode 100644
> index 0000000..30b1500
> --- /dev/null
> +++ b/tools/perf/builtin-config.c
> @@ -0,0 +1,62 @@
> +/*
> + * builtin-config.c
> + *
> + * Copyright (C) 2015, Taeung Song <treeze.taeung@xxxxxxxxx>
> + *
> + */
> +#include "builtin.h"
> +
> +#include "perf.h"
> +
> +#include "util/cache.h"
> +#include "util/parse-options.h"
> +#include "util/util.h"
> +#include "util/debug.h"
> +
> +static const char * const config_usage[] = {
> + "perf config [options]",
> + NULL
> +};
> +
> +enum actions {
> + ACTION_LIST = 1
> +} actions;
> +
> +static struct option config_options[] = {
> + OPT_GROUP("Action"),
> + OPT_SET_UINT('l', "list", &actions,
> + "show current config variables", ACTION_LIST),
> + OPT_END()
> +};
> +
> +static int show_config(const char *key, const char *value,
> + void *cb __maybe_unused)
> +{
> + if (value)
> + printf("%s=%s\n", key, value);
> + else
> + printf("%s\n", key);
> +
> + return 0;
> +}
> +
> +int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
> +{
> + int ret = 0;
> +
> + argc = parse_options(argc, argv, config_options, config_usage,
> + PARSE_OPT_STOP_AT_NON_OPTION);
> +
> + switch (actions) {
> + case ACTION_LIST:
> + default:
> + if (argc) {
> + pr_err("Error: takes no arguments\n");
> + parse_options_usage(config_usage, config_options, "l", 1);
> + return -1;
> + } else
> + ret = perf_config(show_config, NULL);
> + }
> +
> + return ret;
> +}
> diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h
> index 3688ad2..3f871b5 100644
> --- a/tools/perf/builtin.h
> +++ b/tools/perf/builtin.h
> @@ -17,6 +17,7 @@ extern int cmd_annotate(int argc, const char **argv, const char *prefix);
> extern int cmd_bench(int argc, const char **argv, const char *prefix);
> extern int cmd_buildid_cache(int argc, const char **argv, const char *prefix);
> extern int cmd_buildid_list(int argc, const char **argv, const char *prefix);
> +extern int cmd_config(int argc, const char **argv, const char *prefix);
> extern int cmd_diff(int argc, const char **argv, const char *prefix);
> extern int cmd_evlist(int argc, const char **argv, const char *prefix);
> extern int cmd_help(int argc, const char **argv, const char *prefix);
> diff --git a/tools/perf/command-list.txt b/tools/perf/command-list.txt
> index 00fcaf8..acc3ea7 100644
> --- a/tools/perf/command-list.txt
> +++ b/tools/perf/command-list.txt
> @@ -9,6 +9,7 @@ perf-buildid-cache mainporcelain common
> perf-buildid-list mainporcelain common
> perf-data mainporcelain common
> perf-diff mainporcelain common
> +perf-config mainporcelain common
> perf-evlist mainporcelain common
> perf-inject mainporcelain common
> perf-kmem mainporcelain common
> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> index 1fded92..6acbfd5 100644
> --- a/tools/perf/perf.c
> +++ b/tools/perf/perf.c
> @@ -38,6 +38,7 @@ struct cmd_struct {
> static struct cmd_struct commands[] = {
> { "buildid-cache", cmd_buildid_cache, 0 },
> { "buildid-list", cmd_buildid_list, 0 },
> + { "config", cmd_config, 0 },
> { "diff", cmd_diff, 0 },
> { "evlist", cmd_evlist, 0 },
> { "help", cmd_help, 0 },
> --
> 1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/