These are the documentation changes for 4.10.

It's another busy cycle for the docs tree, as the sphinx conversion
 continues.  Highlights include:
 
  - Further work on PDF output, which remains a bit of a pain but should be
    more solid now.
 
  - Five more DocBook template files converted to Sphinx.  Only 27 to go...
    Lots of plain-text files have also been converted and integrated.
 
  - Images in binary formats have been replaced with more source-friendly
    versions.
 
  - Various bits of organizational work, including the renaming of various
    files discussed at the kernel summit.
 
  - New documentation for the device_link mechanism.
 
 ...and, of course, lots of typo fixes and small updates.
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Merge tag 'docs-4.10' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "These are the documentation changes for 4.10.

  It's another busy cycle for the docs tree, as the sphinx conversion
  continues. Highlights include:

   - Further work on PDF output, which remains a bit of a pain but
     should be more solid now.

   - Five more DocBook template files converted to Sphinx. Only 27 to
     go... Lots of plain-text files have also been converted and
     integrated.

   - Images in binary formats have been replaced with more
     source-friendly versions.

   - Various bits of organizational work, including the renaming of
     various files discussed at the kernel summit.

   - New documentation for the device_link mechanism.

  ... and, of course, lots of typo fixes and small updates"

* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
  dma-buf: Extract dma-buf.rst
  Update Documentation/00-INDEX
  docs: 00-INDEX: document directories/files with no docs
  docs: 00-INDEX: remove non-existing entries
  docs: 00-INDEX: add missing entries for documentation files/dirs
  docs: 00-INDEX: consolidate process/ and admin-guide/ description
  scripts: add a script to check if Documentation/00-INDEX is sane
  Docs: change sh -> awk in REPORTING-BUGS
  Documentation/core-api/device_link: Add initial documentation
  core-api: remove an unexpected unident
  ppc/idle: Add documentation for powersave=off
  Doc: Correct typo, "Introdution" => "Introduction"
  Documentation/atomic_ops.txt: convert to ReST markup
  Documentation/local_ops.txt: convert to ReST markup
  Documentation/assoc_array.txt: convert to ReST markup
  docs-rst: parse-headers.pl: cleanup the documentation
  docs-rst: fix media cleandocs target
  docs-rst: media/Makefile: reorganize the rules
  docs-rst: media: build SVG from graphviz files
  docs-rst: replace bayer.png by a SVG image
  ...

Documentation/filesystems/locks.txt

@@ -19,7 +19,7 @@ forever.
 
 This should not cause problems for anybody, since everybody using a
 2.1.x kernel should have updated their C library to a suitable version
-anyway (see the file "Documentation/Changes".)
+anyway (see the file "Documentation/process/changes.rst".)
 
 1.2 Allow Mixed Locks Again
 ---------------------------

Documentation/filesystems/nfs/nfsroot.txt

@@ -11,7 +11,7 @@ Updated 2006 by Horms <[email protected]>
 In order to use a diskless system, such as an X-terminal or printer server
 for example, it is necessary for the root filesystem to be present on a
 non-disk device. This may be an initramfs (see Documentation/filesystems/
-ramfs-rootfs-initramfs.txt), a ramdisk (see Documentation/initrd.txt) or a
+ramfs-rootfs-initramfs.txt), a ramdisk (see Documentation/admin-guide/initrd.rst) or a
 filesystem mounted via NFS. The following text describes on how to use NFS
 for the root filesystem. For the rest of this text 'client' means the
 diskless system, and 'server' means the NFS server.
@@ -284,7 +284,7 @@ They depend on various facilities being available:
 	"kernel <relative-path-below /tftpboot>". The nfsroot parameters
 	are passed to the kernel by adding them to the "append" line.
 	It is common to use serial console in conjunction with pxeliunx,
-	see Documentation/serial-console.txt for more information.
+	see Documentation/admin-guide/serial-console.rst for more information.
 
 	For more information on isolinux, including how to create bootdisks
 	for prebuilt kernels, see http://syslinux.zytor.com/

Documentation/filesystems/proc.txt

@@ -1307,7 +1307,16 @@ second).  The meanings of the columns are as follows, from left to right:
 - nice: niced processes executing in user mode
 - system: processes executing in kernel mode
 - idle: twiddling thumbs
-- iowait: waiting for I/O to complete
+- iowait: In a word, iowait stands for waiting for I/O to complete. But there
+  are several problems:
+  1. Cpu will not wait for I/O to complete, iowait is the time that a task is
+     waiting for I/O to complete. When cpu goes into idle state for
+     outstanding task io, another task will be scheduled on this CPU.
+  2. In a multi-core CPU, the task waiting for I/O to complete is not running
+     on any CPU, so the iowait of each CPU is difficult to calculate.
+  3. The value of iowait field in /proc/stat will decrease in certain
+     conditions.
+  So, the iowait is not reliable by reading from /proc/stat.
 - irq: servicing interrupts
 - softirq: servicing softirqs
 - steal: involuntary wait