Merge tag 'docs-for-linus' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "Some big changes this month, headlined by the addition of a new
  formatted documentation mechanism based on the Sphinx system.

  The objectives here are to make it easier to create better-integrated
  (and more attractive) documents while (eventually) dumping our
  one-of-a-kind, cobbled-together system for something that is widely
  used and maintained by others.  There's a fair amount of information
  what's being done, why, and how to use it in:

    https://lwn.net/Articles/692704/
    https://lwn.net/Articles/692705/

  Closer to home, Documentation/kernel-documentation.rst describes how
  it works.

  For now, the new system exists alongside the old one; you should soon
  see the GPU documentation converted over in the DRM pull and some
  significant media conversion work as well.  Once all the docs have
  been moved over and we're convinced that the rough edges (of which are
  are a few) have been smoothed over, the DocBook-based stuff should go
  away.

  Primary credit is to Jani Nikula for doing the heavy lifting to make
  this stuff actually work; there has also been notable effort from
  Markus Heiser, Daniel Vetter, and Mauro Carvalho Chehab.

  Expect a couple of conflicts on the new index.rst file over the course
  of the merge window; they are trivially resolvable.  That file may be
  a bit of a conflict magnet in the short term, but I don't expect that
  situation to last for any real length of time.

  Beyond that, of course, we have the usual collection of tweaks,
  updates, and typo fixes"

* tag 'docs-for-linus' of git://git.lwn.net/linux: (77 commits)
  doc-rst: kernel-doc: fix handling of address_space tags
  Revert "doc/sphinx: Enable keep_warnings"
  doc-rst: kernel-doc directive, fix state machine reporter
  docs: deprecate kernel-doc-nano-HOWTO.txt
  doc/sphinx: Enable keep_warnings
  Documentation: add watermark_scale_factor to the list of vm systcl file
  kernel-doc: Fix up warning output
  docs: Get rid of some kernel-documentation warnings
  doc-rst: add an option to ignore DocBooks when generating docs
  workqueue: Fix a typo in workqueue.txt
  Doc: ocfs: Fix typo in filesystems/ocfs2-online-filecheck.txt
  Documentation/sphinx: skip build if user requested specific DOCBOOKS
  Documentation: add cleanmediadocs to the documentation targets
  Add .pyc files to .gitignore
  Doc: PM: Fix a typo in intel_powerclamp.txt
  doc-rst: flat-table directive - initial implementation
  Documentation: add meta-documentation for Sphinx and kernel-doc
  Documentation: tiny typo fix in usb/gadget_multi.txt
  Documentation: fix wrong value in md.txt
  bcache: documentation formatting, edited for clarity, stripe alignment notes
  ...

30 files changed, 2653 insertions, 430 deletions

diff --git a/Documentation/.gitignore b/Documentation/.gitignore
new file mode 100644
index 000000000000..e74fec8693b2
--- /dev/null
+++ b/Documentation/.gitignore
@@ -0,0 +1,2 @@
+output
+*.pyc
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index cd077ca0e1b8..cb9a6c6fa83b 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -255,10 +255,10 @@ kbuild/
 	- directory with info about the kernel build process.
 kdump/
 	- directory with mini HowTo on getting the crash dump code to work.
-kernel-doc-nano-HOWTO.txt
-	- mini HowTo on generation and location of kernel documentation files.
 kernel-docs.txt
 	- listing of various WWW + books that document kernel internals.
+kernel-documentation.rst
+	- how to write and format reStructuredText kernel documentation
 kernel-parameters.txt
 	- summary listing of command line / boot prompt args for the kernel.
 kernel-per-CPU-kthreads.txt
diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle
index 9a70ddd16584..a096836723ca 100644
--- a/Documentation/CodingStyle
+++ b/Documentation/CodingStyle
@@ -458,7 +458,7 @@ of the function, telling people what it does, and possibly WHY it does
 it.
 
 When commenting the kernel API functions, please use the kernel-doc format.
-See the files Documentation/kernel-doc-nano-HOWTO.txt and scripts/kernel-doc
+See the files Documentation/kernel-documentation.rst and scripts/kernel-doc
 for details.
 
 Linux style for comments is the C89 "/* ... */" style.
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index d70f9b68174e..01bab5014a4a 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -6,6 +6,8 @@
 # To add a new book the only step required is to add the book to the
 # list of DOCBOOKS.
 
+ifeq ($(IGNORE_DOCBOOKS),)
+
 DOCBOOKS := z8530book.xml device-drivers.xml \
 	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
 	    writing_usb_driver.xml networking.xml \
@@ -33,10 +35,6 @@ PDF_METHOD	= $(prefer-db2x)
 PS_METHOD	= $(prefer-db2x)
 
 
-###
-# The targets that may be used.
-PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs
-
 targets += $(DOCBOOKS)
 BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
 xmldocs: $(BOOKS)
@@ -63,6 +61,9 @@ installmandocs: mandocs
 		sort -k 2 -k 1 | uniq -f 1 | sed -e 's: :/:' | \
 		xargs install -m 644 -t /usr/local/man/man9/
 
+# no-op for the DocBook toolchain
+epubdocs:
+
 ###
 #External programs used
 KERNELDOCXMLREF = $(srctree)/scripts/kernel-doc-xml-ref
@@ -216,10 +217,24 @@ silent_gen_xml = :
 	       -e "s/>/\\>/g";     \
 	   echo "</programlisting>")  > $@
 
+else
+
+# Needed, due to cleanmediadocs
+include Documentation/DocBook/media/Makefile
+
+htmldocs:
+pdfdocs:
+psdocs:
+xmldocs:
+installmandocs:
+
+endif # IGNORE_DOCBOOKS
+
+
 ###
 # Help targets as used by the top-level makefile
 dochelp:
-	@echo  ' Linux kernel internal documentation in different formats:'
+	@echo  ' Linux kernel internal documentation in different formats (DocBook):'
 	@echo  '  htmldocs        - HTML'
 	@echo  '  pdfdocs         - PDF'
 	@echo  '  psdocs          - Postscript'
@@ -228,8 +243,11 @@ dochelp:
 	@echo  '  installmandocs  - install man pages generated by mandocs'
 	@echo  '  cleandocs       - clean all generated DocBook files'
 	@echo
-	@echo  'make DOCBOOKS="s1.xml s2.xml" [target] Generate only docs s1.xml s2.xml'
+	@echo  '  make DOCBOOKS="s1.xml s2.xml" [target] Generate only docs s1.xml s2.xml'
 	@echo  '  valid values for DOCBOOKS are: $(DOCBOOKS)'
+	@echo
+	@echo  "  make IGNORE_DOCBOOKS=1 [target] Don't generate docs from Docbook"
+	@echo  '     This is useful to generate only the ReST docs (Sphinx)'
 
 
 ###
diff --git a/Documentation/Makefile.sphinx b/Documentation/Makefile.sphinx
new file mode 100644
index 000000000000..d8d13c92a178
--- /dev/null
+++ b/Documentation/Makefile.sphinx
@@ -0,0 +1,78 @@
+# -*- makefile -*-
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXBUILD   = sphinx-build
+SPHINXOPTS    =
+PAPER         =
+BUILDDIR      = $(obj)/output
+
+# User-friendly check for sphinx-build
+HAVE_SPHINX := $(shell if which $(SPHINXBUILD) >/dev/null 2>&1; then echo 1; else echo 0; fi)
+
+ifeq ($(HAVE_SPHINX),0)
+
+.DEFAULT:
+	$(warning The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed and in PATH, or set the SPHINXBUILD make variable to point to the full path of the '$(SPHINXBUILD)' executable.)
+	@echo "  SKIP    Sphinx $@ target."
+
+else ifneq ($(DOCBOOKS),)
+
+# Skip Sphinx build if the user explicitly requested DOCBOOKS.
+.DEFAULT:
+	@echo "  SKIP    Sphinx $@ target (DOCBOOKS specified)."
+
+else # HAVE_SPHINX
+
+# User-friendly check for rst2pdf
+HAVE_RST2PDF := $(shell if python -c "import rst2pdf" >/dev/null 2>&1; then echo 1; else echo 0; fi)
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+KERNELDOC       = $(srctree)/scripts/kernel-doc
+KERNELDOC_CONF  = -D kerneldoc_srctree=$(srctree) -D kerneldoc_bin=$(KERNELDOC)
+ALLSPHINXOPTS   = -D version=$(KERNELVERSION) -D release=$(KERNELRELEASE) -d $(BUILDDIR)/.doctrees $(KERNELDOC_CONF) $(PAPEROPT_$(PAPER)) -c $(srctree)/$(src) $(SPHINXOPTS) $(srctree)/$(src)
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+quiet_cmd_sphinx = SPHINX  $@
+      cmd_sphinx = $(SPHINXBUILD) -b $2 $(ALLSPHINXOPTS) $(BUILDDIR)/$2
+
+htmldocs:
+	$(call cmd,sphinx,html)
+
+pdfdocs:
+ifeq ($(HAVE_RST2PDF),0)
+	$(warning The Python 'rst2pdf' module was not found. Make sure you have the module installed to produce PDF output.)
+	@echo "  SKIP    Sphinx $@ target."
+else # HAVE_RST2PDF
+	$(call cmd,sphinx,pdf)
+endif # HAVE_RST2PDF
+
+epubdocs:
+	$(call cmd,sphinx,epub)
+
+xmldocs:
+	$(call cmd,sphinx,xml)
+
+# no-ops for the Sphinx toolchain
+sgmldocs:
+psdocs:
+mandocs:
+installmandocs:
+cleanmediadocs:
+
+cleandocs:
+	$(Q)rm -rf $(BUILDDIR)
+
+dochelp:
+	@echo  ' Linux kernel internal documentation in different formats (Sphinx):'
+	@echo  '  htmldocs        - HTML'
+	@echo  '  pdfdocs         - PDF'
+	@echo  '  epubdocs        - EPUB'
+	@echo  '  xmldocs         - XML'
+	@echo  '  cleandocs       - clean all generated files'
+
+endif # HAVE_SPHINX
diff --git a/Documentation/bcache.txt b/Documentation/bcache.txt
index 32b6c3189d98..a9259b562d5c 100644
--- a/Documentation/bcache.txt
+++ b/Documentation/bcache.txt
@@ -1,4 +1,4 @@
-Say you've got a big slow raid 6, and an X-25E or three. Wouldn't it be
+Say you've got a big slow raid 6, and an ssd or three. Wouldn't it be
 nice if you could use them as cache... Hence bcache.
 
 Wiki and git repositories are at:
@@ -8,7 +8,7 @@ Wiki and git repositories are at:
 
 It's designed around the performance characteristics of SSDs - it only allocates
 in erase block sized buckets, and it uses a hybrid btree/log to track cached
-extants (which can be anywhere from a single sector to the bucket size). It's
+extents (which can be anywhere from a single sector to the bucket size). It's
 designed to avoid random writes at all costs; it fills up an erase block
 sequentially, then issues a discard before reusing it.
 
@@ -55,7 +55,10 @@ immediately.  Without udev, you can manually register devices like this:
 Registering the backing device makes the bcache device show up in /dev; you can
 now format it and use it as normal. But the first time using a new bcache
 device, it'll be running in passthrough mode until you attach it to a cache.
-See the section on attaching.
+If you are thinking about using bcache later, it is recommended to setup all your
+slow devices as bcache backing devices without a cache, and you can choose to add
+a caching device later.
+See 'ATTACHING' section below.
 
 The devices show up as:
 
@@ -72,12 +75,14 @@ To get started:
   mount /dev/bcache0 /mnt
 
 You can control bcache devices through sysfs at /sys/block/bcache<N>/bcache .
+You can also control them through /sys/fs//bcache/<cset-uuid>/ .
 
 Cache devices are managed as sets; multiple caches per set isn't supported yet
 but will allow for mirroring of metadata and dirty data in the future. Your new
 cache set shows up as /sys/fs/bcache/<UUID>
 
-ATTACHING:
+ATTACHING
+---------
 
 After your cache device and backing device are registered, the backing device
 must be attached to your cache set to enable caching. Attaching a backing
@@ -105,7 +110,8 @@ but all the cached data will be invalidated. If there was dirty data in the
 cache, don't expect the filesystem to be recoverable - you will have massive
 filesystem corruption, though ext4's fsck does work miracles.
 
-ERROR HANDLING:
+ERROR HANDLING
+--------------
 
 Bcache tries to transparently handle IO errors to/from the cache device without
 affecting normal operation; if it sees too many errors (the threshold is
@@ -127,12 +133,181 @@ the backing devices to passthrough mode.
    writeback mode). It currently doesn't do anything intelligent if it fails to
    read some of the dirty data, though.
 
-TROUBLESHOOTING PERFORMANCE:
+
+HOWTO/COOKBOOK
+--------------
+
+A) Starting a bcache with a missing caching device
+
+If registering the backing device doesn't help, it's already there, you just need
+to force it to run without the cache:
+	host:~# echo /dev/sdb1 > /sys/fs/bcache/register
+	[  119.844831] bcache: register_bcache() error opening /dev/sdb1: device already registered
+
+Next, you try to register your caching device if it's present. However
+if it's absent, or registration fails for some reason, you can still
+start your bcache without its cache, like so:
+	host:/sys/block/sdb/sdb1/bcache# echo 1 > running
+
+Note that this may cause data loss if you were running in writeback mode.
+
+
+B) Bcache does not find its cache
+
+	host:/sys/block/md5/bcache# echo 0226553a-37cf-41d5-b3ce-8b1e944543a8 > attach
+	[ 1933.455082] bcache: bch_cached_dev_attach() Couldn't find uuid for md5 in set
+	[ 1933.478179] bcache: __cached_dev_store() Can't attach 0226553a-37cf-41d5-b3ce-8b1e944543a8
+	[ 1933.478179] : cache set not found
+
+In this case, the caching device was simply not registered at boot
+or disappeared and came back, and needs to be (re-)registered:
+	host:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/register
+
+
+C) Corrupt bcache crashes the kernel at device registration time:
+
+This should never happen.  If it does happen, then you have found a bug!
+Please report it to the bcache development list: linux-bcache@vger.kernel.org
+
+Be sure to provide as much information that you can including kernel dmesg
+output if available so that we may assist.
+
+
+D) Recovering data without bcache:
+
+If bcache is not available in the kernel, a filesystem on the backing
+device is still available at an 8KiB offset. So either via a loopdev
+of the backing device created with --offset 8K, or any value defined by
+--data-offset when you originally formatted bcache with `make-bcache`.
+
+For example:
+	losetup -o 8192 /dev/loop0 /dev/your_bcache_backing_dev
+
+This should present your unmodified backing device data in /dev/loop0
+
+If your cache is in writethrough mode, then you can safely discard the
+cache device without loosing data.
+
+
+E) Wiping a cache device
+
+host:~# wipefs -a /dev/sdh2
+16 bytes were erased at offset 0x1018 (bcache)
+they were: c6 85 73 f6 4e 1a 45 ca 82 65 f5 7f 48 ba 6d 81
+
+After you boot back with bcache enabled, you recreate the cache and attach it:
+host:~# make-bcache -C /dev/sdh2
+UUID:                   7be7e175-8f4c-4f99-94b2-9c904d227045
+Set UUID:               5bc072a8-ab17-446d-9744-e247949913c1
+version:                0
+nbuckets:               106874
+block_size:             1
+bucket_size:            1024
+nr_in_set:              1
+nr_this_dev:            0
+first_bucket:           1
+[  650.511912] bcache: run_cache_set() invalidating existing data
+[  650.549228] bcache: register_cache() registered cache device sdh2
+
+start backing device with missing cache:
+host:/sys/block/md5/bcache# echo 1 > running
+
+attach new cache:
+host:/sys/block/md5/bcache# echo 5bc072a8-ab17-446d-9744-e247949913c1 > attach
+[  865.276616] bcache: bch_cached_dev_attach() Caching md5 as bcache0 on set 5bc072a8-ab17-446d-9744-e247949913c1
+
+
+F) Remove or replace a caching device
+
+	host:/sys/block/sda/sda7/bcache# echo 1 > detach
+	[  695.872542] bcache: cached_dev_detach_finish() Caching disabled for sda7
+
+	host:~# wipefs -a /dev/nvme0n1p4
+	wipefs: error: /dev/nvme0n1p4: probing initialization failed: Device or resource busy
+	Ooops, it's disabled, but not unregistered, so it's still protected
+
+We need to go and unregister it:
+	host:/sys/fs/bcache/b7ba27a1-2398-4649-8ae3-0959f57ba128# ls -l cache0
+	lrwxrwxrwx 1 root root 0 Feb 25 18:33 cache0 -> ../../../devices/pci0000:00/0000:00:1d.0/0000:70:00.0/nvme/nvme0/nvme0n1/nvme0n1p4/bcache/
+	host:/sys/fs/bcache/b7ba27a1-2398-4649-8ae3-0959f57ba128# echo 1 > stop
+	kernel: [  917.041908] bcache: cache_set_free() Cache set b7ba27a1-2398-4649-8ae3-0959f57ba128 unregistered
+
+Now we can wipe it:
+	host:~# wipefs -a /dev/nvme0n1p4
+	/dev/nvme0n1p4: 16 bytes were erased at offset 0x00001018 (bcache): c6 85 73 f6 4e 1a 45 ca 82 65 f5 7f 48 ba 6d 81
+
+
+G) dm-crypt and bcache
+
+First setup bcache unencrypted and then install dmcrypt on top of
+/dev/bcache<N> This will work faster than if you dmcrypt both the backing
+and caching devices and then install bcache on top. [benchmarks?]
+
+
+H) Stop/free a registered bcache to wipe and/or recreate it
+
+Suppose that you need to free up all bcache references so that you can
+fdisk run and re-register a changed partition table, which won't work
+if there are any active backing or caching devices left on it:
+
+1) Is it present in /dev/bcache* ? (there are times where it won't be)
+
+If so, it's easy:
+	host:/sys/block/bcache0/bcache# echo 1 > stop
+
+2) But if your backing device is gone, this won't work:
+	host:/sys/block/bcache0# cd bcache
+	bash: cd: bcache: No such file or directory
+
+In this case, you may have to unregister the dmcrypt block device that
+references this bcache to free it up:
+	host:~# dmsetup remove oldds1
+	bcache: bcache_device_free() bcache0 stopped
+	bcache: cache_set_free() Cache set 5bc072a8-ab17-446d-9744-e247949913c1 unregistered
+
+This causes the backing bcache to be removed from /sys/fs/bcache and
+then it can be reused.  This would be true of any block device stacking
+where bcache is a lower device.
+
+3) In other cases, you can also look in /sys/fs/bcache/:
+
+host:/sys/fs/bcache# ls -l */{cache?,bdev?}
+lrwxrwxrwx 1 root root 0 Mar  5 09:39 0226553a-37cf-41d5-b3ce-8b1e944543a8/bdev1 -> ../../../devices/virtual/block/dm-1/bcache/
+lrwxrwxrwx 1 root root 0 Mar  5 09:39 0226553a-37cf-41d5-b3ce-8b1e944543a8/cache0 -> ../../../devices/virtual/block/dm-4/bcache/
+lrwxrwxrwx 1 root root 0 Mar  5 09:39 5bc072a8-ab17-446d-9744-e247949913c1/cache0 -> ../../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/ata10/host9/target9:0:0/9:0:0:0/block/sdl/sdl2/bcache/
+
+The device names will show which UUID is relevant, cd in that directory
+and stop the cache:
+	host:/sys/fs/bcache/5bc072a8-ab17-446d-9744-e247949913c1# echo 1 > stop
+
+This will free up bcache references and let you reuse the partition for
+other purposes.
+
+
+
+TROUBLESHOOTING PERFORMANCE
+---------------------------
 
 Bcache has a bunch of config options and tunables. The defaults are intended to
 be reasonable for typical desktop and server workloads, but they're not what you
 want for getting the best possible numbers when benchmarking.
 
+ - Backing device alignment
+
+   The default metadata size in bcache is 8k.  If your backing device is
+   RAID based, then be sure to align this by a multiple of your stride
+   width using `make-bcache --data-offset`. If you intend to expand your
+   disk array in the future, then multiply a series of primes by your
+   raid stripe size to get the disk multiples that you would like.
+
+   For example:  If you have a 64k stripe size, then the following offset
+   would provide alignment for many common RAID5 data spindle counts:
+	64k * 2*2*2*3*3*5*7 bytes = 161280k
+
+   That space is wasted, but for only 157.5MB you can grow your RAID 5
+   volume to the following data-spindle counts without re-aligning:
+	3,4,5,6,7,8,9,10,12,14,15,18,20,21 ...
+
  - Bad write performance
 
    If write performance is not what you expected, you probably wanted to be
@@ -140,7 +315,7 @@ want for getting the best possible numbers when benchmarking.
    maturity, but simply because in writeback mode you'll lose data if something
    happens to your SSD)
 
-   # echo writeback > /sys/block/bcache0/cache_mode
+   # echo writeback > /sys/block/bcache0/bcache/cache_mode
 
  - Bad performance, or traffic not going to the SSD that you'd expect
 
@@ -193,7 +368,9 @@ want for getting the best possible numbers when benchmarking.
    Solution: warm the cache by doing writes, or use the testing branch (there's
    a fix for the issue there).
 
-SYSFS - BACKING DEVICE:
+
+SYSFS - BACKING DEVICE
+----------------------
 
 Available at /sys/block/<bdev>/bcache, /sys/block/bcache*/bcache and
 (if attached) /sys/fs/bcache/<cset-uuid>/bdev*
@@ -238,7 +415,7 @@ sequential_merge
   against all new requests to determine which new requests are sequential
   continuations of previous requests for the purpose of determining sequential
   cutoff. This is necessary if the sequential cutoff value is greater than the
-  maximum acceptable sequential size for any single request. 
+  maximum acceptable sequential size for any single request.
 
 state
   The backing device can be in one of four different states:
@@ -325,7 +502,7 @@ bucket_size
   Size of buckets
 
 cache<0..n>
-  Symlink to each of the cache devices comprising this cache set. 
+  Symlink to each of the cache devices comprising this cache set.
 
 cache_available_percent
   Percentage of cache device which doesn't contain dirty data, and could
diff --git a/Documentation/conf.py b/Documentation/conf.py
new file mode 100644
index 000000000000..792b6338ef19
--- /dev/null
+++ b/Documentation/conf.py
@@ -0,0 +1,414 @@
+# -*- coding: utf-8 -*-
+#
+# The Linux Kernel documentation build configuration file, created by
+# sphinx-quickstart on Fri Feb 12 13:51:46 2016.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys
+import os
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+sys.path.insert(0, os.path.abspath('sphinx'))
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = ['kernel-doc', 'rstFlatTable']
+
+# Gracefully handle missing rst2pdf.
+try:
+    import rst2pdf
+    extensions += ['rst2pdf.pdfbuilder']
+except ImportError:
+    pass
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+# source_suffix = ['.rst', '.md']
+source_suffix = '.rst'
+
+# The encoding of source files.
+#source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = 'The Linux Kernel'
+copyright = '2016, The kernel development community'
+author = 'The kernel development community'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# In a normal build, version and release are are set to KERNELVERSION and
+# KERNELRELEASE, respectively, from the Makefile via Sphinx command line
+# arguments.
+#
+# The following code tries to extract the information by reading the Makefile,
+# when Sphinx is run directly (e.g. by Read the Docs).
+try:
+    makefile_version = None
+    makefile_patchlevel = None
+    for line in open('../Makefile'):
+        key, val = [x.strip() for x in line.split('=', 2)]
+        if key == 'VERSION':
+            makefile_version = val
+        elif key == 'PATCHLEVEL':
+            makefile_patchlevel = val
+        if makefile_version and makefile_patchlevel:
+            break
+except:
+    pass
+finally:
+    if makefile_version and makefile_patchlevel:
+        version = release = makefile_version + '.' + makefile_patchlevel
+    else:
+        sys.stderr.write('Warning: Could not extract kernel version\n')
+        version = release = "unknown version"
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+#today_fmt = '%B %d, %Y'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+exclude_patterns = ['output']
+
+# The reST default role (used for this markup: `text`) to use for all
+# documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+#modindex_common_prefix = []
+
+# If true, keep warnings as "system message" paragraphs in the built documents.
+#keep_warnings = False
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = False
+
+primary_domain = 'C'
+highlight_language = 'C'
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+
+# The Read the Docs theme is available from
+# - https://github.com/snide/sphinx_rtd_theme
+# - https://pypi.python.org/pypi/sphinx_rtd_theme
+# - python-sphinx-rtd-theme package (on Debian)
+try:
+    import sphinx_rtd_theme
+    html_theme = 'sphinx_rtd_theme'
+    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+except ImportError:
+    sys.stderr.write('Warning: The Sphinx \'sphinx_rtd_theme\' HTML theme was not found. Make sure you have the theme installed to produce pretty HTML output. Falling back to the default theme.\n')
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+#html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+#html_static_path = ['_static']
+
+# Add any extra paths that contain custom files (such as robots.txt or
+# .htaccess) here, relative to this directory. These files are copied
+# directly to the root of the documentation.
+#html_extra_path = []
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+#html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+#html_domain_indices = True
+
+# If false, no index is generated.
+#html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+#html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+#html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+#html_file_suffix = None
+
+# Language to be used for generating the HTML full-text search index.
+# Sphinx supports the following languages:
+#   'da', 'de', 'en', 'es', 'fi', 'fr', 'h', 'it', 'ja'
+#   'nl', 'no', 'pt', 'ro', 'r', 'sv', 'tr'
+#html_search_language = 'en'
+
+# A dictionary with options for the search language support, empty by default.
+# Now only 'ja' uses this config value
+#htm