Documentation/basic_profiling.rst: convert to ReST markup

Convert it to ReST markup and add it to the user book:

- Add a title to the document;
- touch spaces/new lines to fix Sphinx format;
- use ``foo`` for commands;
- use quote blocks where needed;
- add it to the user book;
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/basic_profiling.txt

+Basic kernel profiling
+======================
+
+
 These instructions are deliberately very basic. If you want something clever,
-go read the real docs ;-) Please don't add more stuff, but feel free to 
+go read the real docs ;-)
+
+Please don't add more stuff, but feel free to
 correct my mistakes ;-)    (mbligh@aracnet.com)
+
 Thanks to John Levon, Dave Hansen, et al. for help writing this.
 
-<test> is the thing you're trying to measure.
-Make sure you have the correct System.map / vmlinux referenced!
+``<test>`` is the thing you're trying to measure.
+Make sure you have the correct ``System.map`` / ``vmlinux`` referenced!
 
-It is probably easiest to use "make install" for linux and hack
-/sbin/installkernel to copy vmlinux to /boot, in addition to vmlinuz,
-config, System.map, which are usually installed by default.
+It is probably easiest to use ``make install`` for linux and hack
+``/sbin/installkernel`` to copy ``vmlinux`` to ``/boot``, in addition to
+``vmlinuz``, ``config``, ``System.map``, which are usually installed by default.
 
 Readprofile
 -----------
-A recent readprofile command is needed for 2.6, such as found in util-linux
+
+A recent ``readprofile`` command is needed for 2.6, such as found in util-linux
 2.12a, which can be downloaded from:
 
-http://www.kernel.org/pub/linux/utils/util-linux/
+	http://www.kernel.org/pub/linux/utils/util-linux/
 
 Most distributions will ship it already.
 
-Add "profile=2" to the kernel command line.
+Add ``profile=2`` to the kernel command line.
 
-clear		readprofile -r
-		<test>
-dump output	readprofile -m /boot/System.map > captured_profile
+Some ``readprofile`` commands::
+
+	clear		readprofile -r
+			<test>
+	dump output	readprofile -m /boot/System.map > captured_profile
 
 Oprofile
 --------
 
 Get the source (see Changes for required version) from
-http://oprofile.sourceforge.net/ and add "idle=poll" to the kernel command
+http://oprofile.sourceforge.net/ and add ``idle=poll`` to the kernel command
 line.
 
-Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y & reboot on new kernel
+Configure with ``CONFIG_PROFILING=y`` and ``CONFIG_OPROFILE=y`` & reboot on new kernel::
 
-./configure --with-kernel-support
-make install
+	./configure --with-kernel-support
+	make install
 
 For superior results, be sure to enable the local APIC. If opreport sees
 a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance
 penalty.
 
-One time setup:
-		opcontrol --setup --vmlinux=/boot/vmlinux
+One time setup::
+
+			opcontrol --setup --vmlinux=/boot/vmlinux
+
+Some ``opcontrol`` commands::
 
-clear		opcontrol --reset
-start		opcontrol --start
+	clear		opcontrol --reset
+	start		opcontrol --start
 		<test>
-stop		opcontrol --stop
-dump output	opreport >  output_file
+	stop		opcontrol --stop
+	dump output	opreport >  output_file
 
-To only report on the kernel, run opreport -l /boot/vmlinux > output_file
+To only report on the kernel, run ``opreport -l /boot/vmlinux > output_file``
 
 A reset is needed to clear old statistics, which survive a reboot.