Randy reported below build error.

> In file included from ../include/linux/balloon_compaction.h:48:0,
>                  from ../mm/balloon_compaction.c:11:
> ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default]
>  static inline int compaction_register_node(struct node *node)
> ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
> ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default]
>  static inline void compaction_unregister_node(struct node *node)
>

It was caused by non-lru page migration which needs compaction.h but
compaction.h doesn't include any header to be standalone.

I think proper header for non-lru page migration is migrate.h rather
than compaction.h because migrate.h has already headers needed to work
non-lru page migration indirectly like isolate_mode_t, migrate_mode
MIGRATEPAGE_SUCCESS.

[akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix]
Link: http://lkml.kernel.org/r/20160610003304.GE29779@bboxSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add info about tmpfs/shmem with huge pages.

Link: http://lkml.kernel.org/r/1466021202-61880-38-git-send-email-kirill.shutemov@linux.intel.comSigned-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The idea borrowed from Peter's patch from patchset on speculative page
faults[1]:

Instead of passing around the endless list of function arguments,
replace the lot with a single structure so we can change context without
endless function signature changes.

The changes are mostly mechanical with exception of faultaround code:
filemap_map_pages() got reworked a bit.

This patch is preparation for the next one.

[1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org

Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.comSigned-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add description of THP handling into unevictable-lru.txt.

Link: http://lkml.kernel.org/r/1466021202-61880-7-git-send-email-kirill.shutemov@linux.intel.comSigned-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have allowed migration for only LRU pages until now and it was enough
to make high-order pages.  But recently, embedded system(e.g., webOS,
android) uses lots of non-movable pages(e.g., zram, GPU memory) so we
have seen several reports about troubles of small high-order allocation.
For fixing the problem, there were several efforts (e,g,.  enhance
compaction algorithm, SLUB fallback to 0-order page, reserved memory,
vmalloc and so on) but if there are lots of non-movable pages in system,
their solutions are void in the long run.

So, this patch is to support facility to change non-movable pages with
movable.  For the feature, this patch introduces functions related to
migration to address_space_operations as well as some page flags.

If a driver want to make own pages movable, it should define three
functions which are function pointers of struct
address_space_operations.

1. bool (*isolate_page) (struct page *page, isolate_mode_t mode);

What VM expects on isolate_page function of driver is to return *true*
if driver isolates page successfully.  On returing true, VM marks the
page as PG_isolated so concurrent isolation in several CPUs skip the
page for isolation.  If a driver cannot isolate the page, it should
return *false*.

Once page is successfully isolated, VM uses page.lru fields so driver
shouldn't expect to preserve values in that fields.

2. int (*migratepage) (struct address_space *mapping,
		struct page *newpage, struct page *oldpage, enum migrate_mode);

After isolation, VM calls migratepage of driver with isolated page.  The
function of migratepage is to move content of the old page to new page
and set up fields of struct page newpage.  Keep in mind that you should
indicate to the VM the oldpage is no longer movable via
__ClearPageMovable() under page_lock if you migrated the oldpage
successfully and returns 0.  If driver cannot migrate the page at the
moment, driver can return -EAGAIN.  On -EAGAIN, VM will retry page
migration in a short time because VM interprets -EAGAIN as "temporal
migration failure".  On returning any error except -EAGAIN, VM will give
up the page migration without retrying in this time.

Driver shouldn't touch page.lru field VM using in the functions.

3. void (*putback_page)(struct page *);

If migration fails on isolated page, VM should return the isolated page
to the driver so VM calls driver's putback_page with migration failed
page.  In this function, driver should put the isolated page back to the
own data structure.

4. non-lru movable page flags

There are two page flags for supporting non-lru movable page.

* PG_movable

Driver should use the below function to make page movable under
page_lock.

	void __SetPageMovable(struct page *page, struct address_space *mapping)

It needs argument of address_space for registering migration family
functions which will be called by VM.  Exactly speaking, PG_movable is
not a real flag of struct page.  Rather than, VM reuses page->mapping's
lower bits to represent it.

	#define PAGE_MAPPING_MOVABLE 0x2
	page->mapping = page->mapping | PAGE_MAPPING_MOVABLE;

so driver shouldn't access page->mapping directly.  Instead, driver
should use page_mapping which mask off the low two bits of page->mapping
so it can get right struct address_space.

For testing of non-lru movable page, VM supports __PageMovable function.
However, it doesn't guarantee to identify non-lru movable page because
page->mapping field is unified with other variables in struct page.  As
well, if driver releases the page after isolation by VM, page->mapping
doesn't have stable value although it has PAGE_MAPPING_MOVABLE (Look at
__ClearPageMovable).  But __PageMovable is cheap to catch whether page
is LRU or non-lru movable once the page has been isolated.  Because LRU
pages never can have PAGE_MAPPING_MOVABLE in page->mapping.  It is also
good for just peeking to test non-lru movable pages before more
expensive checking with lock_page in pfn scanning to select victim.

For guaranteeing non-lru movable page, VM provides PageMovable function.
Unlike __PageMovable, PageMovable functions validates page->mapping and
mapping->a_ops->isolate_page under lock_page.  The lock_page prevents
sudden destroying of page->mapping.

Driver using __SetPageMovable should clear the flag via
__ClearMovablePage under page_lock before the releasing the page.

* PG_isolated

To prevent concurrent isolation among several CPUs, VM marks isolated
page as PG_isolated under lock_page.  So if a CPU encounters PG_isolated
non-lru movable page, it can skip it.  Driver doesn't need to manipulate
the flag because VM will set/clear it automatically.  Keep in mind that
if driver sees PG_isolated page, it means the page have been isolated by
VM so it shouldn't touch page.lru field.  PG_isolated is alias with
PG_reclaim flag so driver shouldn't use the flag for own purpose.

[opensource.ganesh@gmail.com: mm/compaction: remove local variable is_lru]
  Link: http://lkml.kernel.org/r/20160618014841.GA7422@leo-test
Link: http://lkml.kernel.org/r/1464736881-24886-3-git-send-email-minchan@kernel.orgSigned-off-by: NGioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NGanesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: John Einar Reitan <john.reitan@foss.arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

zram documentation is a mix of different styles: spaces, tabs, tabs +
spaces, etc.  Clean it up.

Link: http://lkml.kernel.org/r/20160531122017.2878-6-sergey.senozhatsky@gmail.comSigned-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no way to get a string with all the crypto comp algorithms
supported by the crypto comp engine, so we need to maintain our own
backends list.  At the same time we additionally need to use
crypto_has_comp() to make sure that the user has requested a compression
algorithm that is recognized by the crypto comp engine.  Relying on
/proc/crypto is not an options here, because it does not show
not-yet-inserted compression modules.

Example:

 modprobe zram
 cat /proc/crypto | grep -i lz4
 modprobe lz4
 cat /proc/crypto | grep -i lz4
name         : lz4
driver       : lz4-generic
module       : lz4

So the user can't tell exactly if the lz4 is really supported from
/proc/crypto output, unless someone or something has loaded it.

This patch also adds crypto_has_comp() to zcomp_available_show().  We
store all the compression algorithms names in zcomp's `backends' array,
regardless the CONFIG_CRYPTO_FOO configuration, but show only those that
are also supported by crypto engine.  This helps user to know the exact
list of compression algorithms that can be used.

Example:
  module lz4 is not loaded yet, but is supported by the crypto
  engine. /proc/crypto has no information on this module, while
  zram's `comp_algorithm' lists it:

 cat /proc/crypto | grep -i lz4

 cat /sys/block/zram0/comp_algorithm
[lzo] lz4 deflate lz4hc 842

We still use the `backends' array to determine if the requested
compression backend is known to crypto api.  This array, however, may not
contain some entries, therefore as the last step we call crypto_has_comp()
function which attempts to insmod the requested compression algorithm to
determine if crypto api supports it.  The advantage of this method is that
now we permit the usage of out-of-tree crypto compression modules
(implementing S/W or H/W compression).

[sergey.senozhatsky@gmail.com: zram-use-crypto-api-to-check-alg-availability-v3]
  Link: http://lkml.kernel.org/r/20160604024902.11778-4-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-5-sergey.senozhatsky@gmail.comSigned-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These are originally from Matthew Wilcox and were part of his huge
"mm,fs,dax: Change ->pmd_fault to ->huge_fault" patch that was part of
PUD support.

I'm breaking these small changes out as they stand on their own and add
useful information to Documentation/filesystems/dax.txt.

Link: http://lkml.kernel.org/r/20160714214049.20075-1-ross.zwisler@linux.intel.comSigned-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Tested-by: NFushen Chen <fchen@apm.com>
Tested-by: NToan Le <toanle@apm.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

pm_runtime_forbid was the wrong knob, this is the better one.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

add card Hauppauge WinTV-QuadHD-DVB to the list.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

References at the rst files for C functions generated via
kernel-doc should use :c:func:.

Fix it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

This struct is mentioned at the kAPI docbook. So, let's document
it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Reorganize the order of the document, putting the chapters
on a more logical order and renaming some sections.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Now that the only remaining chapters at v4l2-framework are
the introduction ones, let' s rename the file.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Move the v4l2 clocks stuff from v4l2-framework to a separate
file and adds an attention that came from the v4l2-clk.h.

Note: as this is meant to be a temporary kAPI, and it is
used only by two drivers (soc_camera and em28xx), where
the first one is in deprecation process, it probably not
a worth effort to document its header.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Add cross-references with the kernel-doc functions/structs
and improve the markups.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Move the v4l2_fh specific content from v4l2-framework.rst
to v4l2-fh.rst.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

This header file was undocumented. Add documentation for it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Improve events documentation by adding cross references,
sub-titles and other markup elements.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Move the v4l2 event-specific text from v4l2-framework.rst
to v4l2-event.rst. That helps to keep the text together with
the functions it describes, and makes easier to identify
documentation gaps.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

As we merged the videobuf chapter at the kABI section, and it
is a way more complete, just remove the small videobuf chapter
that came from framework.txt.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Add cross-references for the functions/structs and add
the markup tags to improve its display.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Move the documentation for video device node creation to
a separate file.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Add documentation for v4l2-dev.h, and put it at v4l2-framework.rst,
where struct video_device is currently documented.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The v4l2_subdev reference was using the wrong tag. Fix it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

There are some subdev-specific functions at v4l2-common.h
that are mentioned at v4l2-subdev.rst.

Document them.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The two new sections were missing cross-references, and had
some other minor issues with the markups. Add such things.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

There are two additional subdev-specific sections at the
v4l2-framework file. Move them to the subdev chapter, in order
to better organize the book.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The Async API is actually part of the v4l2 subdev.
Move its declarations to it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Enrich the subdevice description by linking it to the
functions and structs from v4l2-subdev.h.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

There are lots of documentation about V4L2 subdevices at
v4l2-framework.rst. Move them to its specific chapter at
v4l2-subdev.rst.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

This document describes the main kAPI interfaces for the
v4l2-device.h header. Add cross references to the documentation
produced via kernel-doc.

While here, also use monotonic font for constants.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Part of the contents of v4l2-framework is related to the
kAPI defined by v4l2-device. Move such contents to the
v4l2-device.rst.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Sphinx produce a 1:1 mapping between a rst file and an html file.

So, we need to split the kernel-doc tags on multiple documents.

A side effect is that we're now having a better name for each
section of the kAPI documentation.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The functions at v4l2-device.h are not using the proper
markups. Add it, and include at the v4l2-core.rst.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The kAPI, v4l-drivers and dvb-drivers never used the
GNU FDL license. The addition of such license header were
just due to copy-and-paste. So, let's fix it.

As the media_kapi were part of device-drivers.tmp, it is
under GPL v2+.

The other two books is an agregation of files without any
license explicitly specified. So, they're all bound to the
Kernel's COPYING license. So, they're GPL v2 only.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The uAPI book has 5 parts, but they lost numeration after
conversion to rst. Manually number those parts, and make
the main index with 1 depth, to only show the parts and
the annexes.

At each part, use :maxwidth: 5, in order to show a more
complete index.

While here, fix the cross-references between different
books.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Fix all remaining media warnings with ReST that are fixable
without changing at the Sphinx code.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>