Merge branch 'akpm' (patches from Andrew)

Merge second patch-bomb from Andrew Morton:

 - a couple of hotfixes

 - the rest of MM

 - a new timer slack control in procfs

 - a couple of procfs fixes

 - a few misc things

 - some printk tweaks

 - lib/ updates, notably to radix-tree.

 - add my and Nick Piggin's old userspace radix-tree test harness to
   tools/testing/radix-tree/.  Matthew said it was a godsend during the
   radix-tree work he did.

 - a few code-size improvements, switching to __always_inline where gcc
   screwed up.

 - partially implement character sets in sscanf

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  sscanf: implement basic character sets
  lib/bug.c: use common WARN helper
  param: convert some "on"/"off" users to strtobool
  lib: add "on"/"off" support to kstrtobool
  lib: update single-char callers of strtobool()
  lib: move strtobool() to kstrtobool()
  include/linux/unaligned: force inlining of byteswap operations
  include/uapi/linux/byteorder, swab: force inlining of some byteswap operations
  include/asm-generic/atomic-long.h: force inlining of some atomic_long operations
  usb: common: convert to use match_string() helper
  ide: hpt366: convert to use match_string() helper
  ata: hpt366: convert to use match_string() helper
  power: ab8500: convert to use match_string() helper
  power: charger_manager: convert to use match_string() helper
  drm/edid: convert to use match_string() helper
  pinctrl: convert to use match_string() helper
  device property: convert to use match_string() helper
  lib/string: introduce match_string() helper
  radix-tree tests: add test for radix_tree_iter_next
  radix-tree tests: add regression3 test
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt
index 21cf34f3ddb2..d9cb65cf5cfd 100644
--- a/Documentation/vm/transhuge.txt
+++ b/Documentation/vm/transhuge.txt
@@ -113,9 +113,26 @@ guaranteed, but it may be more likely in case the allocation is for a
 MADV_HUGEPAGE region.
 
 echo always >/sys/kernel/mm/transparent_hugepage/defrag
+echo defer >/sys/kernel/mm/transparent_hugepage/defrag
 echo madvise >/sys/kernel/mm/transparent_hugepage/defrag
 echo never >/sys/kernel/mm/transparent_hugepage/defrag
 
+"always" means that an application requesting THP will stall on allocation
+failure and directly reclaim pages and compact memory in an effort to
+allocate a THP immediately. This may be desirable for virtual machines
+that benefit heavily from THP use and are willing to delay the VM start
+to utilise them.
+
+"defer" means that an application will wake kswapd in the background
+to reclaim pages and wake kcompact to compact memory so that THP is
+available in the near future. It's the responsibility of khugepaged
+to then install the THP pages later.
+
+"madvise" will enter direct reclaim like "always" but only for regions
+that are have used madvise(MADV_HUGEPAGE). This is the default behaviour.
+
+"never" should be self-explanatory.
+
 By default kernel tries to use huge zero page on read page fault.
 It's possible to disable huge zero page by writing 0 or enable it
 back by writing 1:
@@ -229,6 +246,11 @@ thp_split_page is incremented every time a huge page is split into base
 thp_split_page_failed is is incremented if kernel fails to split huge
 	page. This can happen if the page was pinned by somebody.
 
+thp_deferred_split_page is incremented when a huge page is put onto split
+	queue. This happens when a huge page is partially unmapped and
+	splitting it would free up some memory. Pages on split queue are
+	going to be split under memory pressure.
+
 thp_split_pmd is incremented every time a PMD split into table of PTEs.
 	This can happen, for instance, when application calls mprotect() or
 	munmap() on part of huge page. It doesn't split huge page, only