Pull md updates for 3.4 from Neil Brown:
 "Mostly tidying up code in preparation for some bigger changes next
  time.

  A few bug fixes tagged for -stable.

  Main functionality change is that some RAID10 arrays can now grow to
  use extra space that may have been made available on the individual
  devices."

Fixed up trivial conflicts with the k[un]map_atomic() cleanups in
drivers/md/bitmap.c.

* tag 'md-3.4' of git://neil.brown.name/md: (22 commits)
  md: Add judgement bb->unacked_exist in function md_ack_all_badblocks().
  md: fix clearing of the 'changed' flags for the bad blocks list.
  md/bitmap: discard CHUNK_BLOCK_SHIFT macro
  md/bitmap: remove unnecessary indirection when allocating.
  md/bitmap: remove some pointless locking.
  md/bitmap: change a 'goto' to a normal 'if' construct.
  md/bitmap: move printing of bitmap status to bitmap.c
  md/bitmap: remove some unused noise from bitmap.h
  md/raid10 - support resizing some RAID10 arrays.
  md/raid1: handle merge_bvec_fn in member devices.
  md/raid10: handle merge_bvec_fn in member devices.
  md: add proper merge_bvec handling to RAID0 and Linear.
  md: tidy up rdev_for_each usage.
  md/raid1,raid10: avoid deadlock during resync/recovery.
  md/bitmap: ensure to load bitmap when creating via sysfs.
  md: don't set md arrays to readonly on shutdown.
  md: allow re-add to failed arrays.
  md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read().
  md: Use existed macros instead of numbers
  md/raid5: removed unused 'added_devices' variable.
  ...

Pull x86 "urgent" leftovers from Ingo Molnar:
 "Pending x86/urgent bits that were not high prio enough to warrant
  -rc-less v3.3-final inclusion."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: Fix pointer math issue in handle_ramdisks()
  x86/ioapic: Add register level checks to detect bogus io-apic entries
  x86, mce: Fix rcu splat in drain_mce_log_buffer()
  x86, memblock: Move mem_hole_size() to .init

Pull x86 platform changes from Ingo Molnar.

Removes the Moorestown platform that nobody ever used.

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform: Move APIC ID validity check into platform APIC code
  x86/olpc/xo15/sci: Enable lid close wakeup control
  x86/geode/net5501: Add platform driver for Soekris Engineering net5501
  x86/geode/alix2: Supplement driver to include GPIO button support
  x86/mid/powerbtn: Use MSIC read/write instead of ipc_scu
  x86/mid/thermal: Turn off thermistor
  x86/mid/thermal: Add msic_thermal alias
  x86/mid/thermal: Convert to use Intel MSIC API
  x86/mid/scu_ipc: Remove Moorestown support
  x86/mid: Kill off Moorestown
  x86/mrst: Add msic_thermal platform support
  x86/config: Select MSIC MFD driver on Intel Medfield platform
  x86/mid: Remove Intel Moorestown
  x86/mrst: Set ISA bus type for fake MP IRQs
  x86/ioapic: Use legacy_pic to set correct gsi-irq mapping

Pull MCE changes from Ingo Molnar.

* 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Fix return value of mce_chrdev_read() when erst is disabled
  x86/mce: Convert static array of pointers to per-cpu variables
  x86/mce: Replace hard coded hex constants with symbolic defines
  x86/mce: Recognise machine check bank signature for data path error
  x86/mce: Handle "action required" errors
  x86/mce: Add mechanism to safely save information in MCE handler
  x86/mce: Create helper function to save addr/misc when needed
  HWPOISON: Add code to handle "action required" errors.
  HWPOISON: Clean up memory_failure() vs. __memory_failure()

Pull x86/fpu changes from Ingo Molnar.

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  i387: Split up <asm/i387.h> into exported and internal interfaces
  i387: Uninline the generic FP helpers that we expose to kernel modules

Pull x86/build changes from Ingo Molnar.

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, build: Fix portability issues when cross-building
  x86, tools: Remove unneeded header files from tools/build.c
  USB: ffs-test: Don't duplicate {get,put}_unaligned*() functions
  x86, efi: Fix endian issues and unaligned accesses
  x86, boot: Restrict CFLAGS for hostprogs
  x86, mkpiggy: Don't open code put_unaligned_le32()
  x86, relocs: Don't open code put_unaligned_le32()
  tools/include: Add byteshift headers for endian access

Pull x86/eficross (booting 32/64-bit kernel from 64/32-bit EFI) from Ingo Molnar

* 'x86-eficross-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: Allow basic init with mixed 32/64-bit efi/kernel
  x86, efi: Add basic error handling
  x86, efi: Cleanup config table walking
  x86, efi: Convert printk to pr_*()
  x86, efi: Refactor efi_init() a bit

Pull x86/debug changes from Ingo Molnar.

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Fix section warnings
  x86-64: Fix CFI data for common_interrupt()
  x86: Properly _init-annotate NMI selftest code
  x86/debug: Fix/improve the show_msr=<cpus> debug print out

Merge branches 'x86-cpu-for-linus', 'x86-boot-for-linus', 'x86-cpufeature-for-linus', 'x86-process-for-linus' and 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull trivial x86 branches from Ingo Molnar: small one-liners to fix up
details.

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Remove some noise from boot log when starting cpus

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, boot: Fix port argument to inl() function

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, cpufeature: Add CPU features from Intel document 319433-012A

* 'x86-process-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86_64: Record stack pointer before task execution begins

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/UV: Lower UV rtc clocksource rating

Pull x86/atomic changes from Ingo Molnar.

* 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: atomic64 assembly improvements
  x86: Adjust asm constraints in atomic64 wrappers

Pull x86/asm changes from Ingo Molnar

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Include probe_roms.h in probe_roms.c
  x86/32: Print control and debug registers for kerenel context
  x86: Tighten dependencies of CPU_SUP_*_32
  x86/numa: Improve internode cache alignment
  x86: Fix the NMI nesting comments
  x86-64: Improve insn scheduling in SAVE_ARGS_IRQ
  x86-64: Fix CFI annotations for NMI nesting code
  bitops: Add missing parentheses to new get_order macro
  bitops: Optimise get_order()
  bitops: Adjust the comment on get_order() to describe the size==0 case
  x86/spinlocks: Eliminate TICKET_MASK
  x86-64: Handle byte-wise tail copying in memcpy() without a loop
  x86-64: Fix memcpy() to support sizes of 4Gb and above
  x86-64: Fix memset() to support sizes of 4Gb and above
  x86-64: Slightly shorten copy_page()

Merge first batch of patches from Andrew Morton:
 "A few misc things and all the MM queue"

* emailed from Andrew Morton <akpm@linux-foundation.org>: (92 commits)
  memcg: avoid THP split in task migration
  thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE
  memcg: clean up existing move charge code
  mm/memcontrol.c: remove unnecessary 'break' in mem_cgroup_read()
  mm/memcontrol.c: remove redundant BUG_ON() in mem_cgroup_usage_unregister_event()
  mm/memcontrol.c: s/stealed/stolen/
  memcg: fix performance of mem_cgroup_begin_update_page_stat()
  memcg: remove PCG_FILE_MAPPED
  memcg: use new logic for page stat accounting
  memcg: remove PCG_MOVE_LOCK flag from page_cgroup
  memcg: simplify move_account() check
  memcg: remove EXPORT_SYMBOL(mem_cgroup_update_page_stat)
  memcg: kill dead prev_priority stubs
  memcg: remove PCG_CACHE page_cgroup flag
  memcg: let css_get_next() rely upon rcu_read_lock()
  cgroup: revert ss_id_lock to spinlock
  idr: make idr_get_next() good for rcu_read_lock()
  memcg: remove unnecessary thp check in page stat accounting
  memcg: remove redundant returns
  memcg: enum lru_list lru
  ...

Pull powerpc merge from Benjamin Herrenschmidt:
 "Here's the powerpc batch for this merge window.  It is going to be a
  bit more nasty than usual as in touching things outside of
  arch/powerpc mostly due to the big iSeriesectomy :-) We finally got
  rid of the bugger (legacy iSeries support) which was a PITA to
  maintain and that nobody really used anymore.

  Here are some of the highlights:

   - Legacy iSeries is gone.  Thanks Stephen ! There's still some bits
     and pieces remaining if you do a grep -ir series arch/powerpc but
     they are harmless and will be removed in the next few weeks
     hopefully.

   - The 'fadump' functionality (Firmware Assisted Dump) replaces the
     previous (equivalent) "pHyp assisted dump"...  it's a rewrite of a
     mechanism to get the hypervisor to do crash dumps on pSeries, the
     new implementation hopefully being much more reliable.  Thanks
     Mahesh Salgaonkar.

   - The "EEH" code (pSeries PCI error handling & recovery) got a big
     spring cleaning, motivated by the need to be able to implement a
     new backend for it on top of some new different type of firwmare.

     The work isn't complete yet, but a good chunk of the cleanups is
     there.  Note that this adds a field to struct device_node which is
     not very nice and which Grant objects to.  I will have a patch soon
     that moves that to a powerpc private data structure (hopefully
     before rc1) and we'll improve things further later on (hopefully
     getting rid of the need for that pointer completely).  Thanks Gavin
     Shan.

   - I dug into our exception & interrupt handling code to improve the
     way we do lazy interrupt handling (and make it work properly with
     "edge" triggered interrupt sources), and while at it found & fixed
     a wagon of issues in those areas, including adding support for page
     fault retry & fatal signals on page faults.

   - Your usual random batch of small fixes & updates, including a bunch
     of new embedded boards, both Freescale and APM based ones, etc..."

I fixed up some conflicts with the generalized irq-domain changes from
Grant Likely, hopefully correctly.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (141 commits)
  powerpc/ps3: Do not adjust the wrapper load address
  powerpc: Remove the rest of the legacy iSeries include files
  powerpc: Remove the remaining CONFIG_PPC_ISERIES pieces
  init: Remove CONFIG_PPC_ISERIES
  powerpc: Remove FW_FEATURE ISERIES from arch code
  tty/hvc_vio: FW_FEATURE_ISERIES is no longer selectable
  powerpc/spufs: Fix double unlocks
  powerpc/5200: convert mpc5200 to use of_platform_populate()
  powerpc/mpc5200: add options to mpc5200_defconfig
  powerpc/mpc52xx: add a4m072 board support
  powerpc/mpc5200: update mpc5200_defconfig to fit for charon board
  Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup
  powerpc/44x: Add additional device support for APM821xx SoC and Bluestone board
  powerpc/44x: Add support PCI-E for APM821xx SoC and Bluestone board
  MAINTAINERS: Update PowerPC 4xx tree
  powerpc/44x: The bug fixed support for APM821xx SoC and Bluestone board
  powerpc: document the FSL MPIC message register binding
  powerpc: add support for MPIC message register API
  powerpc/fsl: Added aliased MSIIR register address to MSI node in dts
  powerpc/85xx: mpc8548cds - add 36-bit dts
  ...

Pull m68knommu arch updates from Greg Ungerer:
 "Includes a cleanup of the non-MMU linker script (it now almost
  exclusively uses the well defined linker script support macros and
  definitions).  Some more merging of MMU and non-MMU common files
  (specifically the arch process.c, ptrace and time.c).  And a big
  cleanup of the massively duplicated ColdFire device definition code.

  Overall we remove about 2000 lines of code, and end up with a single
  set of platform device definitions for the serial ports, ethernet
  ports and QSPI ports common in most ColdFire SoCs.

  I expect you will get a merge conflict on arch/m68k/kernel/process.c,
  in cpu_idle().  It should be relatively strait forward to fixup."

And cpu_idle() conflict resolution was indeed trivial (merging the
nommu/mmu versions of process.c trivially conflicting with the
conversion to use the schedule_preempt_disabled() helper function)

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: (57 commits)
  m68knommu: factor more common ColdFire cpu reset code
  m68knommu: make 528x CPU reset register addressing consistent
  m68knommu: make 527x CPU reset register addressing consistent
  m68knommu: make 523x CPU reset register addressing consistent
  m68knommu: factor some common ColdFire cpu reset code
  m68knommu: move old ColdFire timers init from CPU init to timers code
  m68knommu: clean up init code in ColdFire 532x startup
  m68knommu: clean up init code in ColdFire 528x startup
  m68knommu: clean up init code in ColdFire 523x startup
  m68knommu: merge common ColdFire QSPI platform setup code
  m68knommu: make 532x QSPI platform addressing consistent
  m68knommu: make 528x QSPI platform addressing consistent
  m68knommu: make 527x QSPI platform addressing consistent
  m68knommu: make 5249 QSPI platform addressing consistent
  m68knommu: make 523x QSPI platform addressing consistent
  m68knommu: make 520x QSPI platform addressing consistent
  m68knommu: merge common ColdFire FEC platform setup code
  m68knommu: make 532x FEC platform addressing consistent
  m68knommu: make 528x FEC platform addressing consistent
  m68knommu: make 527x FEC platform addressing consistent
  ...

Pull gfs2 changes from Steven Whitehouse.

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: Change truncate page allocation to be GFP_NOFS
  GFS2: call gfs2_write_alloc_required for each chunk
  GFS2: Clean up log flush header writing
  GFS2: Remove a __GFP_NOFAIL allocation
  GFS2: Flush pending glock work when evicting an inode
  GFS2: make sure rgrps are up to date in func gfs2_blk2rgrpd
  GFS2: Eliminate sd_rindex_mutex
  GFS2: Unlock rindex mutex on glock error
  GFS2: Make bd_cmp() static
  GFS2: Sort the ordered write list
  GFS2: FITRIM ioctl support
  GFS2: Move two functions from log.c to lops.c
  GFS2: glock statistics gathering

Currently we can't do task migration among memory cgroups without THP
split, which means processes heavily using THP experience large overhead
in task migration.  This patch introduces the code for moving charge of
THP and makes THP more valuable.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These macros will be used in a later patch, where all usages are expected
to be optimized away without #ifdef CONFIG_TRANSPARENT_HUGEPAGE.  But to
detect unexpected usages, we convert the existing BUG() to BUILD_BUG().

[akpm@linux-foundation.org: fix build in mm/pgtable-generic.c]
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- Replace lengthy function name is_target_pte_for_mc() with a shorter
  one in order to avoid ugly line breaks.

- explicitly use MC_TARGET_* instead of simply using integers.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the following code:

	if (type == _MEM)
		thresholds = &memcg->thresholds;
	else if (type == _MEMSWAP)
		thresholds = &memcg->memsw_thresholds;
	else
		BUG();

	BUG_ON(!thresholds);

The BUG_ON() seems redundant.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A grammatical fix.

Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mem_cgroup_begin_update_page_stat() should be very fast because it's
called very frequently.  Now, it needs to look up page_cgroup and its
memcg....this is slow.

This patch adds a global variable to check "any memcg is moving or not".
With this, the caller doesn't need to visit page_cgroup and memcg.

Here is a test result.  A test program makes page faults onto a file,
MAP_SHARED and makes each page's page_mapcount(page) > 1, and free the
range by madvise() and page fault again.  This program causes 26214400
times of page fault onto a file(size was 1G.) and shows shows the cost of
mem_cgroup_begin_update_page_stat().

Before this patch for mem_cgroup_begin_update_page_stat()

    [kamezawa@bluextal test]$ time ./mmap 1G

    real    0m21.765s
    user    0m5.999s
    sys     0m15.434s

    27.46%     mmap  mmap               [.] reader
    21.15%     mmap  [kernel.kallsyms]  [k] page_fault
     9.17%     mmap  [kernel.kallsyms]  [k] filemap_fault
     2.96%     mmap  [kernel.kallsyms]  [k] __do_fault
     2.83%     mmap  [kernel.kallsyms]  [k] __mem_cgroup_begin_update_page_stat

After this patch

    [root@bluextal test]# time ./mmap 1G

    real    0m21.373s
    user    0m6.113s
    sys     0m15.016s

In usual path, calls to __mem_cgroup_begin_update_page_stat() goes away.

Note: we may be able to remove this optimization in future if
      we can get pointer to memcg directly from struct page.

[akpm@linux-foundation.org: don't return a void]
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NGreg Thelen <gthelen@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the new lock scheme for updating memcg's page stat, we don't need a
flag PCG_FILE_MAPPED which was duplicated information of page_mapped().

[hughd@google.com: cosmetic fix]
[hughd@google.com: add comment to MEM_CGROUP_CHARGE_TYPE_MAPPED case in __mem_cgroup_uncharge_common()]
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NGreg Thelen <gthelen@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now, page-stat-per-memcg is recorded into per page_cgroup flag by
duplicating page's status into the flag.  The reason is that memcg has a
feature to move a page from a group to another group and we have race
between "move" and "page stat accounting",

Under current logic, assume CPU-A and CPU-B.  CPU-A does "move" and CPU-B
does "page stat accounting".

When CPU-A goes 1st,

            CPU-A                           CPU-B
                                    update "struct page" info.
    move_lock_mem_cgroup(memcg)
    see pc->flags
    copy page stat to new group
    overwrite pc->mem_cgroup.
    move_unlock_mem_cgroup(memcg)
                                    move_lock_mem_cgroup(mem)
                                    set pc->flags
                                    update page stat accounting
                                    move_unlock_mem_cgroup(mem)

stat accounting is guarded by move_lock_mem_cgroup() and "move" logic
(CPU-A) doesn't see changes in "struct page" information.

But it's costly to have the same information both in 'struct page' and
'struct page_cgroup'.  And, there is a potential problem.

For example, assume we have PG_dirty accounting in memcg.
PG_..is a flag for struct page.
PCG_ is a flag for struct page_cgroup.
(This is just an example. The same problem can be found in any
 kind of page stat accounting.)

	  CPU-A                               CPU-B
      TestSet PG_dirty
      (delay)                        TestClear PG_dirty
                                     if (TestClear(PCG_dirty))
                                          memcg->nr_dirty--
      if (TestSet(PCG_dirty))
          memcg->nr_dirty++

Here, memcg->nr_dirty = +1, this is wrong.  This race was reported by Greg
Thelen <gthelen@google.com>.  Now, only FILE_MAPPED is supported but
fortunately, it's serialized by page table lock and this is not real bug,
_now_,

If this potential problem is caused by having duplicated information in
struct page and struct page_cgroup, we may be able to fix this by using
original 'struct page' information.  But we'll have a problem in "move
account"

Assume we use only PG_dirty.

         CPU-A                   CPU-B
    TestSet PG_dirty
    (delay)                    move_lock_mem_cgroup()
                               if (PageDirty(page))
                                      new_memcg->nr_dirty++
                               pc->mem_cgroup = new_memcg;
                               move_unlock_mem_cgroup()
    move_lock_mem_cgroup()
    memcg = pc->mem_cgroup
    new_memcg->nr_dirty++

accounting information may be double-counted.  This was original reason to
have PCG_xxx flags but it seems PCG_xxx has another problem.

I think we need a bigger lock as

     move_lock_mem_cgroup(page)
     TestSetPageDirty(page)
     update page stats (without any checks)
     move_unlock_mem_cgroup(page)

This fixes both of problems and we don't have to duplicate page flag into
page_cgroup.  Please note: move_lock_mem_cgroup() is held only when there
are possibility of "account move" under the system.  So, in most path,
status update will go without atomic locks.

This patch introduces mem_cgroup_begin_update_page_stat() and
mem_cgroup_end_update_page_stat() both should be called at modifying
'struct page' information if memcg takes care of it.  as

     mem_cgroup_begin_update_page_stat()
     modify page information
     mem_cgroup_update_page_stat()
     => never check any 'struct page' info, just update counters.
     mem_cgroup_end_update_page_stat().

This patch is slow because we need to call begin_update_page_stat()/
end_update_page_stat() regardless of accounted will be changed or not.  A
following patch adds an easy optimization and reduces the cost.

[akpm@linux-foundation.org: s/lock/locked/]
[hughd@google.com: fix deadlock by avoiding stat lock when anon]
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Greg Thelen <gthelen@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PCG_MOVE_LOCK is used for bit spinlock to avoid race between overwriting
pc->mem_cgroup and page statistics accounting per memcg.  This lock helps
to avoid the race but the race is very rare because moving tasks between
cgroup is not a usual job.  So, it seems using 1bit per page is too
costly.

This patch changes this lock as per-memcg spinlock and removes
PCG_MOVE_LOCK.

If smaller lock is required, we'll be able to add some hashes but I'd like
to start from this.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NGreg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In memcg, for avoiding take-lock-irq-off at accessing page_cgroup, a
logic, flag + rcu_read_lock(), is used.  This works as following

     CPU-A                     CPU-B
                             rcu_read_lock()
    set flag
                             if(flag is set)
                                   take heavy lock
                             do job.
    synchronize_rcu()        rcu_read_unlock()
    take heavy lock.

In recent discussion, it's argued that using per-cpu value for this flag
just complicates the code because 'set flag' is very rare.

This patch changes 'flag' implementation from percpu to atomic_t.  This
will be much simpler.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NGreg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As described in the log, I guess EXPORT was for preparing dirty
accounting.  But _now_, we don't need to export this.  Remove this for
now.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: NGreg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This code was removed in 25edde03 ("vmscan: kill prev_priority
completely")
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We record 'the page is cache' with the PCG_CACHE bit in page_cgroup.
Here, "CACHE" means anonymous user pages (and SwapCache).  This doesn't
include shmem.

Considering callers, at charge/uncharge, the caller should know what the
page is and we don't need to record it by using one bit per page.

This patch removes PCG_CACHE bit and make callers of
mem_cgroup_charge_statistics() to specify what the page is.

About page migration: Mapping of the used page is not touched during migra
tion (see page_remove_rmap) so we can rely on it and push the correct
charge type down to __mem_cgroup_uncharge_common from end_migration for
unused page.  The force flag was misleading was abused for skipping the
needless page_mapped() / PageCgroupMigration() check, as we know the
unused page is no longer mapped and cleared the migration flag just a few
lines up.  But doing the checks is no biggie and it's not worth adding
another flag just to skip them.

[akpm@linux-foundation.org: checkpatch fixes]
[hughd@google.com: fix PageAnon uncharging]
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove lock and unlock around css_get_next()'s call to idr_get_next().
memcg iterators (only users of css_get_next) already did rcu_read_lock(),
and its comment demands that; but add a WARN_ON_ONCE to make sure of it.
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit c1e2ee2d ("memcg: replace ss->id_lock with a rwlock") has now
been seen to cause the unfair behavior we should have expected from
converting a spinlock to an rwlock: softlockup in cgroup_mkdir(), whose
get_new_cssid() is waiting for the wlock, while there are 19 tasks using
the rlock in css_get_next() to get on with their memcg workload (in an
artificial test, admittedly).  Yet lib/idr.c was made suitable for RCU
way back: revert that commit, restoring ss->id_lock to a spinlock.
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make one small adjustment to idr_get_next(): take the height from the top
layer (stable under RCU) instead of from the root (unprotected by RCU), as
idr_find() does: so that it can be used with RCU locking.  Copied comment
on RCU locking from idr_find().
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit e94c8a9c ("memcg: make mem_cgroup_split_huge_fixup() more
efficient") removed move_lock_page_cgroup().  So we do not have to check
PageTransHuge in mem_cgroup_update_page_stat() and fallback into the
locked accounting because both move_account() and thp split are done
with compound_lock so they cannot race.

The race between update vs.  move is protected by mem_cgroup_stealed.

PageTransHuge pages shouldn't appear in this code path currently because
we are tracking only file pages at the moment but later we are planning
to track also other pages (e.g.  mlocked ones).
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: NAcked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Ying Han<yinghan@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove redundant returns from ends of functions, and one blank line.
Signed-off-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mostly we use "enum lru_list lru": change those few "l"s to "lru"s.
Signed-off-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I never understood why we need a MEM_CGROUP_ZSTAT(mz, idx) macro to
obscure the LRU counts.  For easier searching? So call it lru_size
rather than bare count (lru_length sounds better, but would be wrong,
since each huge page raises lru_size hugely).
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace mem and mem_cont stragglers in memcontrol.c by memcg.
Signed-off-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Correct an #endif comment in memcontrol.h from MEM_CONT to MEM_RES_CTLR.
Signed-off-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When swapon() was not passed the SWAP_FLAG_DISCARD option, sys_swapon()
will still perform a discard operation.  This can cause problems if
discard is slow or buggy.

Reverse the order of the check so that a discard operation is performed
only if the sys_swapon() caller is attempting to enable discard.
Signed-off-by: NShaohua Li <shli@fusionio.com>
Reported-by: NHolger Kiehl <Holger.Kiehl@dwd.de>
Tested-by: NHolger Kiehl <Holger.Kiehl@dwd.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reset the reclaim mode in shrink_active_list() to RECLAIM_MODE_SINGLE |
RECLAIM_MODE_ASYNC.  (sync/async sign is used only in shrink_page_list
and does not affect shrink_active_list)

Currenly shrink_active_list() sometimes works in lumpy-reclaim mode, if
RECLAIM_MODE_LUMPYRECLAIM is left over from an earlier
shrink_inactive_list().  Meanwhile, in age_active_anon()
sc->reclaim_mode is totally zero.  So the current behavior is too
complex and confusing, and this looks like bug.

In general, shrink_active_list() populates the inactive list for the
next shrink_inactive_list().  Lumpy shring_inactive_list() isolates
pages around the chosen one from both the active and inactive lists.
So, there is no reason for lumpy isolation in shrink_active_list().

See also: https://lkml.org/lkml/2012/3/15/583Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Proposed-by: NHugh Dickins <hughd@google.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>