docs/vm: page_owner: convert to ReST format

.. _page_owner:

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page owner: Tracking about who allocated each page

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* Introduction

Introduction

============

page owner is for the tracking about who allocated each page.

It can be used to debug memory leak or to find a memory hogger.

label patching functionality is available. Following is the kernel's code

size change due to this facility.

- Without page owner

- Without page owner::

   text    data     bss     dec     hex filename

   40662   1493     644   42799    a72f mm/page_alloc.o

- With page owner

- With page owner::

   text    data     bss     dec     hex filename

   40892   1493     644   43029    a815 mm/page_alloc.o

   1427      24       8    1459     5b3 mm/page_ext.o

page extension feature. Anyway, after that, no page is left in

un-tracking state.

* Usage

Usage

=====

1) Build user-space helper::

1) Build user-space helper

	cd tools/vm

	make page_owner_sort

2) Enable page owner

	Add "page_owner=on" to boot cmdline.

2) Enable page owner: add "page_owner=on" to boot cmdline.

3) Do the job what you want to debug

4) Analyze information from page owner

4) Analyze information from page owner::

	cat /sys/kernel/debug/page_owner > page_owner_full.txt

	grep -v ^PFN page_owner_full.txt > page_owner.txt

	./page_owner_sort page_owner.txt sorted_page_owner.txt

   See the result about who allocated each page

	in the sorted_page_owner.txt.

   in the ``sorted_page_owner.txt``.