[PATCH 2/6] perf config: Document examples to get config key-value pairs in man page

[Taeung Song <treeze.taeung@gmail.com>]

Explain how to query particular config items in config file
and how to get several config items from user or system config file
using '--user' or '--system' options.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/Documentation/perf-config.txt | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index cb081ac5..1714b0c 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -8,6 +8,8 @@ perf-config - Get and set variables in a configuration file.
 SYNOPSIS
 --------
 [verse]
+'perf config' [<file-option>] [section.name ...]
+or
 'perf config' [<file-option>] -l | --list
 
 DESCRIPTION
@@ -118,6 +120,22 @@ Given a $HOME/.perfconfig like this:
 		children = true
 		group = true
 
+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
 ~~~~~~~~~
 
-- 
2.7.4