perf path: Make mkpath thread safe, remove 16384 bytes from .bss

Avoid 4 static arrays for paths, pass in a char[] buffer to use. Makes
mkpath thread safe for the small number of users. Also removes 16,384
bytes from .bss.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Ross Zwisler <zwisler@chromium.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20230526183401.2326121-13-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Remove util.h from where it is not needed

Check that it is not needed and remove, fixing up some fallout for
places where it was only serving to get something else.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-9h6dg6lsqe2usyqjh5rrues4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf debug: Remove needless include directives from debug.h

All we need there is a forward declaration for 'union perf_event', so
remove it from there and add missing header directives in places using
things from this indirect include.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7ftk0ztstqub1tirjj8o8xbl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Remove perf.h from source files not needing it

With the movement of lots of stuff out of perf.h to other headers we
ended up not needing it in lots of places, remove it from those places.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-c718m0sxxwp73lp9d8vpihb4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Add missing headers, mostly stdlib.h

Part of the erosion of util/util.h, that will lose its include stdlib.h,
we need to add it to places where it is needed but was getting it
indirectly.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-1imnqezw99ahc07fjeb51qby@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Show the configuration when no arguments are provided

More convenient thah having to recall what letter is about
showing/listing/dumping the configuration, i.e. no arguments means
-l/--list:

# perf config
llvm.dump-obj=true
trace.default_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
trace.show_zeros=yes
trace.show_duration=no
# perf config -l
llvm.dump-obj=true
trace.default_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
trace.show_zeros=yes
trace.show_duration=no
# perf config -h

Usage: perf config [<file-option>] [options] [section.name[=value] ...]

-l, --list show current config variables
--system use system config file
--user use user config file

#

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-z2n63avz6tliqb5gmu4l1dti@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

perf config: Write a config file just once

Currently set_config() can be repeatedly called for each input config on
the below case:

$ perf config kmem.default=slab report.children=false ...

But it's a waste, so only once write a config file gathering all given
config key=value pairs.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1504754331-9776-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Check not only section->from_system_config but also item's

Currently section->from_system_config is being checked multiple times.
item->from_system_config should be checked instead, when iterating thru
the items in a section. Fix it.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1504754325-9724-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools include: Adopt strstarts() from the kernel

Replacing prefixcmp(), same purpose, inverted result, so standardize on
the kernel variant, to reduce silly differences among tools/ and the
kernel sources, making it easier for people to work in both codebases.

And then doing:

if (strstarts(option, "no-"))

Looks clearer than doing:

if (!prefixcmp(option, "no-"))

To figure out if option starts witn "no-".

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kaei42gi7lpa8subwtv7eug8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Refactor the code using 'ret' variable in cmd_config()

To simplify the code related to 'ret' variable in cmd_config(),
initialize 'ret' with -1 instead of 0 and use goto to perform resource
release at the end of the function, setting ret to zero just before the
out_err label, as usual in the kernel sources.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1497671202-20495-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Check error cases of {show_spec, set}_config()

show_spec_config() and set_config() can be called multiple times
in the loop in cmd_config().

However, The error cases of them wasn't checked, so fix it.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1497671197-20450-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Invert an if statement to reduce nesting in cmd_config()

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1494241650-32210-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Refactor a duplicated code for obtaining config file name

We were doing the same sequence to figure out what is the config
pathname to use, fix it by doing it before those two uses.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1493209268-5543-2-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Remove unused 'prefix' from builtin functions

We got it from the git sources but never used it for anything, with the
place where this would be somehow used remaining:

static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
{
prefix = NULL;
if (p->option & RUN_SETUP)
prefix = NULL; /* setup_perf_directory(); */

Ditch it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-uw5swz05vol0qpr32c5lpvus@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Mark where are config items from (user or system)

To write config items to a particular config file, we should know where
is each config section and item from.

Current setting functionality of perf-config use autogenerating way by
overwriting collected config items to a config file.

For example, when collecting config items from user and system config
files (i.e. ~/.perfconfig and $(sysconf)/perfconfig), perf_config_set
can contain both user and system config items. So we should know where
each value is from to avoid merging user and system config items on user
config file.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Nambong Ha <over3025@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wookje Kwon <aweee0@gmail.com>
Link: http://lkml.kernel.org/r/1478241862-31230-7-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Add support setting variables in a config file

Add setting feature that can add config variables with their values to a
config file (i.e. user or system config file) or modify config key-value
pairs in a config file. For the syntax examples:

perf config [<file-option>] [section.name[=value] ...]

e.g. You can set the ui.show-headers to false with

# perf config ui.show-headers=false

If you want to add or modify several config items, you can do like

# perf config annotate.show_nr_jumps=false kmem.default=slab

Committer notes:

Testing it:

$ perf config -l
top.children=true
report.children=false
$
$ perf config top.children=false
$ perf config -l
top.children=false
report.children=false
$
$ perf config kmem.default=slab
$ perf config -l
top.children=false
report.children=false
kmem.default=slab
$

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Nambong Ha <over3025@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wookje Kwon <aweee0@gmail.com>
Link: http://lkml.kernel.org/r/1478241862-31230-5-git-send-email-treeze.taeung@gmail.com
[ Combined patch with docs update with this one ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Validate config variable arguments before trying use them

You can show the values for several config items as below:

# perf config report.queue-size call-graph.record-mode

but it is necessary to more precisely check arguments, before passing
them to show_spec_config(). This validation function would be also used
when parsing config key-value pairs arguments in the near future.

Committer notes:

Testing it:

$ perf config bla.
The config variable does not contain a variable name: bla.
$ perf config .bla
The config variable does not contain a section name: .bla
$ perf config bla.bla
$

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Nambong Ha <over3025@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wookje Kwon <aweee0@gmail.com>
Link: http://lkml.kernel.org/r/1478241862-31230-4-git-send-email-treeze.taeung@gmail.com
[ Fix some spelling errors ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Add support for getting config key-value pairs

Add a functionality getting specific config key-value pairs.
For the syntax examples,

perf config [<file-option>] [section.name ...]

e.g. To query config items 'report.queue-size' and 'report.children', do

# perf config report.queue-size report.children

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Nambong Ha <over3025@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wookje Kwon <aweee0@gmail.com>
Link: http://lkml.kernel.org/r/1478241862-31230-2-git-send-email-treeze.taeung@gmail.com
[ Combined patch with docs update with this one ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Reimplement show_config() using config_set__for_each

Recently config_set__for_each got added. In order to let show_config()
be short and clear, rewrite this function using it.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1466691272-24117-4-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Introduce new init() and exit()

Many sub-commands use perf_config() but everytime perf_config() is
called, perf_config() always read config files. (i.e. user config
'~/.perfconfig' and system config '$(sysconfdir)/perfconfig')

But it is better to use the config set that already contains all config
key-value pairs to avoid this repetitive work reading the config files
in perf_config(). (the config set mean a static variable 'config_set')

In other words, if new perf_config__init() is called, only first time
'config_set' is initialized collecting all configs from the config
files. And then we could use new perf_config() like old perf_config().
When a sub-command finished, free the config set by perf_config__exit()
at run_builtin().

If we do, 'config_set' can be reused wherever perf_config() is called
and a feature of old perf_config() is the same as new perf_config() work
without the repetitive work that read the config files.

In summary, in order to use features about configuration,
we can call the functions at perf.c and other source files as below.

# initialize a config set
perf_config__init()

# configure actual variables from a config set
perf_config()

# eliminate allocated config set
perf_config__exit()

# destroy existing config set and initialize a new config set.
perf_config__refresh()

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1466691272-24117-3-git-send-email-treeze.taeung@gmail.com
[ 'init' counterpart is 'exit', not 'finish' ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Make show_config() use perf_config_set

Currently show_config() has a problem when user and system config files
have the same config variables i.e.:

# cat ~/.perfconfig
[top]
children = false

When $(sysconfdir) is /usr/local/etc

# cat /usr/local/etc/perfconfig
[top]
children = true

Before:

# perf config --user --list
top.children=false

# perf config --system --list
top.children=true

# perf config --list
top.children=true
top.children=false

Because perf_config() can call show_config() each the config file (user
and system). Fix it.

After:

# perf config --user --list
top.children=false

# perf config --system --list
top.children=true

# perf config --list
top.children=false

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1460620401-23430-3-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf config: Add '--system' and '--user' options to select which config file is used

The '--system' option means $(sysconfdir)/perfconfig and '--user' means
$HOME/.perfconfig. If none is used, both system and user config file are
read. E.g.:

# perf config [<file-option>] [options]

With an specific config file:

# perf config --user | --system

or both user and system config file:

# perf config

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1455126685-32367-2-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf subcmd: Create subcmd library

Move the subcommand-related files from perf to a new library named
libsubcmd.a.

Since we're moving files anyway, go ahead and rename 'exec_cmd.*' to
'exec-cmd.*' to be consistent with the naming of all the other files.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/c0a838d4c878ab17fee50998811612b2281355c1.1450193761.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Add 'perf config' command

The perf configuration file contains many variables to change various
aspects of each of its tools, including output, disk usage, etc.

But looking at the state of configuration is difficult and there's no
documentation about config variables except for the variables in
perfconfig.example exist.

So this patch adds a 'perf-config' command with a '--list' option.

perf config [options]

display current perf config variables.
# perf config -l | --list

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1447768424-17327-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>