Re: [PATCH v7 1/7] perf tools: Add 'perf-config' command

From: Namhyung Kim
Date: Tue Oct 20 2015 - 23:10:46 EST


Hi Taeung,

sorry for late!

On Sun, Oct 04, 2015 at 04:35:04PM +0900, Taeung Song wrote:
> 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>

Some nitpicks below, other than that

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Thanks,
Namhyung


> ---
> tools/perf/Build | 1 +
> tools/perf/Documentation/perf-config.txt | 396 +++++++++++++++++++++++++++++++
> 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, 462 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..e8013b3
> --- /dev/null
> +++ b/tools/perf/Documentation/perf-config.txt
> @@ -0,0 +1,396 @@
> +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, 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
> +that are composed of a name and value.
> +
> +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 belong 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 (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
> + 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, comma separated as below.
> +
> + medium = green, lightgray
> +
> + If you want to keep the background or the foregroud color set for your
> + terminal, replace the desired value with 'default'. For instance:
> +
> + medium = default, default
> +
> + Available 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 if the TUI browser will be used
> + for subcommands 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 if GTK+2 GUI browser for
> + each subcommand. By default, GUI can be enabled if perf detects the
> + required library during build and this config option can control it.
> + Available subcommands are 'top', 'report' and 'annotate'.
> +
> +buildid.*::
> + buildid.dir::
> + 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. If you want to disable it,
> + set buildid.dir to /dev/null. The default is $HOME/.debug
> +
> +annotate.*::
> + Thereâre options which work with a âannotateâ sub-command.
> + This options 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 let âannotateâ print a list of assembly code with the source code.
> + 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

??? I think this is when the option is 'true' that means *hide* the
source code.


> +
> + 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;

And this is the 'false' case - show me the source.


> +
> + 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

There was a bug in handling this option and I've sent a fix.

Anyway, it seems that these annotate options are only applied to TUI.


> +
> + 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.
> +
> + 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.

It seems not to be applied for --stdio.


> +
> +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
>
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