memory-hotplug: common APIs to support page tables hot-remove

When memory is removed, the corresponding pagetables should alse be
removed.  This patch introduces some common APIs to support vmemmap
pagetable and x86_64 architecture direct mapping pagetable removing.

All pages of virtual mapping in removed memory cannot be freed if some
pages used as PGD/PUD include not only removed memory but also other
memory.  So this patch uses the following way to check whether a page
can be freed or not.

1) When removing memory, the page structs of the removed memory are
   filled with 0FD.

2) All page structs are filled with 0xFD on PT/PMD, PT/PMD can be
   cleared.  In this case, the page used as PT/PMD can be freed.

For direct mapping pages, update direct_pages_count[level] when we freed
their pagetables.  And do not free the pages again because they were
freed when offlining.

For vmemmap pages, free the pages and their pagetables.

For larger pages, do not split them into smaller ones because there is
no way to know if the larger page has been split.  As a result, there is
no way to decide when to split.  We deal the larger pages in the
following way:

1) For direct mapped pages, all the pages were freed when they were
   offlined.  And since menmory offline is done section by section, all
   the memory ranges being removed are aligned to PAGE_SIZE.  So only need
   to deal with unaligned pages when freeing vmemmap pages.

2) For vmemmap pages being used to store page_struct, if part of the
   larger page is still in use, just fill the unused part with 0xFD.  And
   when the whole page is fulfilled with 0xFD, then free the larger page.

[akpm@linux-foundation.org: fix typo in comment]
[tangchen@cn.fujitsu.com: do not calculate direct mapping pages when freeing vmemmap pagetables]
[tangchen@cn.fujitsu.com: do not free direct mapping pages twice]
[tangchen@cn.fujitsu.com: do not free page split from hugepage one by one]
[tangchen@cn.fujitsu.com: do not split pages when freeing pagetable pages]
[akpm@linux-foundation.org: use pmd_page_vaddr()]
[akpm@linux-foundation.org: fix used-uninitialised bug]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: move pgdat_resize_lock into sparse_remove_one_section()

In __remove_section(), we locked pgdat_resize_lock when calling
sparse_remove_one_section().  This lock will disable irq.  But we don't
need to lock the whole function.  If we do some work to free pagetables
in free_section_usemap(), we need to call flush_tlb_all(), which need
irq enabled.  Otherwise the WARN_ON_ONCE() in smp_call_function_many()
will be triggered.

If we lock the whole sparse_remove_one_section(), then we come to this call trace:

  ------------[ cut here ]------------
  WARNING: at kernel/smp.c:461 smp_call_function_many+0xbd/0x260()
  Hardware name: PRIMEQUEST 1800E
  ......
  Call Trace:
    smp_call_function_many+0xbd/0x260
    smp_call_function+0x3b/0x50
    on_each_cpu+0x3b/0xc0
    flush_tlb_all+0x1c/0x20
    remove_pagetable+0x14e/0x1d0
    vmemmap_free+0x18/0x20
    sparse_remove_one_section+0xf7/0x100
    __remove_section+0xa2/0xb0
    __remove_pages+0xa0/0xd0
    arch_remove_memory+0x6b/0xc0
    remove_memory+0xb8/0xf0
    acpi_memory_device_remove+0x53/0x96
    acpi_device_remove+0x90/0xb2
    __device_release_driver+0x7c/0xf0
    device_release_driver+0x2f/0x50
    acpi_bus_remove+0x32/0x6d
    acpi_bus_trim+0x91/0x102
    acpi_bus_hot_remove_device+0x88/0x16b
    acpi_os_execute_deferred+0x27/0x34
    process_one_work+0x20e/0x5c0
    worker_thread+0x12e/0x370
    kthread+0xee/0x100
    ret_from_fork+0x7c/0xb0
  ---[ end trace 25e85300f542aa01 ]---

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap

For removing memmap region of sparse-vmemmap which is allocated bootmem,
memmap region of sparse-vmemmap needs to be registered by
get_page_bootmem().  So the patch searches pages of virtual mapping and
registers the pages by get_page_bootmem().

NOTE: register_page_bootmem_memmap() is not implemented for ia64,
      ppc, s390, and sparc.  So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE
      and revert register_page_bootmem_info_node() when platform doesn't
      support it.

      It's implemented by adding a new Kconfig option named
      CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected
      by memory-hotplug feature fully supported archs(currently only on
      x86_64).

      Since we have 2 config options called MEMORY_HOTPLUG and
      MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately,
      and codes in function register_page_bootmem_info_node() are only
      used for collecting infomation for hot-remove, so reside it under
      MEMORY_HOTREMOVE.

      Besides page_isolation.c selected by MEMORY_ISOLATION under
      MEMORY_HOTPLUG is also such case, move it too.

[mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE]
[linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()]
[mhocko@suse.cz: remove the arch specific functions without any implementation]
[linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed]
[rientjes@google.com: fix defined but not used warning]
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Wu Jianguo <wujianguo@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: introduce new arch_remove_memory() for removing page table

For removing memory, we need to remove page tables.  But it depends on
architecture.  So the patch introduce arch_remove_memory() for removing
page table.  Now it only calls __remove_pages().

Note: __remove_pages() for some archtecuture is not implemented
      (I don't know how to implement it for s390).

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: remove /sys/firmware/memmap/X sysfs

When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start,
type} sysfs files are created.  But there is no code to remove these
files.  This patch implements the function to remove them.

We cannot free firmware_map_entry which is allocated by bootmem because
there is no way to do so when the system is up.  But we can at least
remember the address of that memory and reuse the storage when the
memory is added next time.

This patch also introduces a new list map_entries_bootmem to link the
map entries allocated by bootmem when they are removed, and a lock to
protect it.  And these entries will be reused when the memory is
hot-added again.

The idea is suggestted by Andrew Morton.

NOTE: It is unsafe to return an entry pointer and release the
      map_entries_lock.  So we should not hold the map_entries_lock
      separately in firmware_map_find_entry() and
      firmware_map_remove_entry().  Hold the map_entries_lock across find
      and remove /sys/firmware/memmap/X operation.

       And also, users of these two functions need to be careful to
      hold the lock when using these two functions.

[tangchen@cn.fujitsu.com: Hold spinlock across find|remove /sys operation]
[tangchen@cn.fujitsu.com: fix the wrong comments of map_entries]
[tangchen@cn.fujitsu.com: reuse the storage of /sys/firmware/memmap/X/ allocated by bootmem]
[tangchen@cn.fujitsu.com: fix section mismatch problem]
[tangchen@cn.fujitsu.com: fix the doc format in drivers/firmware/memmap.c]
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: remove redundant codes

offlining memory blocks and checking whether memory blocks are offlined
are very similar.  This patch introduces a new function to remove
redundant codes.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: check whether all memory blocks are offlined or not when removing memory

We remove the memory like this:

 1. lock memory hotplug
 2. offline a memory block
 3. unlock memory hotplug
 4. repeat 1-3 to offline all memory blocks
 5. lock memory hotplug
 6. remove memory(TODO)
 7. unlock memory hotplug

All memory blocks must be offlined before removing memory.  But we don't
hold the lock in the whole operation.  So we should check whether all
memory blocks are offlined before step6.  Otherwise, kernel maybe
panicked.

Offlining a memory block and removing a memory device can be two
different operations.  Users can just offline some memory blocks without
removing the memory device.  For this purpose, the kernel has held
lock_memory_hotplug() in __offline_pages().  To reuse the code for
memory hot-remove, we repeat step 1-3 to offline all the memory blocks,
repeatedly lock and unlock memory hotplug, but not hold the memory
hotplug lock in the whole operation.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memory-hotplug: try to offline the memory twice to avoid dependence

memory can't be offlined when CONFIG_MEMCG is selected.  For example:
there is a memory device on node 1.  The address range is [1G, 1.5G).
You will find 4 new directories memory8, memory9, memory10, and memory11
under the directory /sys/devices/system/memory/.

If CONFIG_MEMCG is selected, we will allocate memory to store page
cgroup when we online pages.  When we online memory8, the memory stored
page cgroup is not provided by this memory device.  But when we online
memory9, the memory stored page cgroup may be provided by memory8.  So
we can't offline memory8 now.  We should offline the memory in the
reversed order.

When the memory device is hotremoved, we will auto offline memory
provided by this memory device.  But we don't know which memory is
onlined first, so offlining memory may fail.  In such case, iterate
twice to offline the memory.  1st iterate: offline every non primary
memory block.  2nd iterate: offline primary (i.e.  first added) memory
block.

This idea is suggested by KOSAKI Motohiro.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memory_hotplug: no need to check res twice in add_memory

Remove one redundant check of res.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: make do_mmap_pgoff return populate as a size in bytes, not as a bool

do_mmap_pgoff() rounds up the desired size to the next PAGE_SIZE
multiple, however there was no equivalent code in mm_populate(), which
caused issues.

This could be fixed by introduced the same rounding in mm_populate(),
however I think it's preferable to make do_mmap_pgoff() return populate
as a size rather than as a boolean, so we don't have to duplicate the
size rounding logic in mm_populate().

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce VM_POPULATE flag to better deal with racy userspace programs

The vm_populate() code populates user mappings without constantly
holding the mmap_sem.  This makes it susceptible to racy userspace
programs: the user mappings may change while vm_populate() is running,
and in this case vm_populate() may end up populating the new mapping
instead of the old one.

In order to reduce the possibility of userspace getting surprised by
this behavior, this change introduces the VM_POPULATE vma flag which
gets set on vmas we want vm_populate() to work on.  This way
vm_populate() may still end up populating the new mapping after such a
race, but only if the new mapping is also one that the user has
requested (using MAP_SHARED, MAP_LOCKED or mlock) to be populated.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: directly use __mlock_vma_pages_range() in find_extend_vma()

In find_extend_vma(), we don't need mlock_vma_pages_range() to verify
the vma type - we know we're working with a stack.  So, we can call
directly into __mlock_vma_pages_range(), and remove the last
make_pages_present() call site.

Note that we don't use mm_populate() here, so we can't release the
mmap_sem while allocating new stack pages.  This is deemed acceptable,
because the stack vmas grow by a bounded number of pages at a time, and
these are anon pages so we don't have to read from disk to populate
them.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove flags argument to mmap_region

After the MAP_POPULATE handling has been moved to mmap_region() call
sites, the only remaining use of the flags argument is to pass the
MAP_NORESERVE flag.  This can be just as easily handled by
do_mmap_pgoff(), so do that and remove the mmap_region() flags
parameter.

[akpm@linux-foundation.org: remove double parens]
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use mm_populate() for mremap() of VM_LOCKED vmas

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use mm_populate() when adjusting brk with MCL_FUTURE in effect

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use mm_populate() for blocking remap_file_pages()

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce mm_populate() for populating new vmas

When creating new mappings using the MAP_POPULATE / MAP_LOCKED flags (or
with MCL_FUTURE in effect), we want to populate the pages within the
newly created vmas.  This may take a while as we may have to read pages
from disk, so ideally we want to do this outside of the write-locked
mmap_sem region.

This change introduces mm_populate(), which is used to defer populating
such mappings until after the mmap_sem write lock has been released.
This is implemented as a generalization of the former do_mlock_pages(),
which accomplished the same task but was using during mlock() /
mlockall().

Signed-off-by: Michel Lespinasse <walken@google.com>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remap_file_pages() fixes

We have many vma manipulation functions that are fast in the typical
case, but can optionally be instructed to populate an unbounded number
of ptes within the region they work on:

 - mmap with MAP_POPULATE or MAP_LOCKED flags;
 - remap_file_pages() with MAP_NONBLOCK not set or when working on a
   VM_LOCKED vma;
 - mmap_region() and all its wrappers when mlock(MCL_FUTURE) is in
   effect;
 - brk() when mlock(MCL_FUTURE) is in effect.

Current code handles these pte operations locally, while the
sourrounding code has to hold the mmap_sem write side since it's
manipulating vmas.  This means we're doing an unbounded amount of pte
population work with mmap_sem held, and this causes problems as Andy
Lutomirski reported (we've hit this at Google as well, though it's not
entirely clear why people keep trying to use mlock(MCL_FUTURE) in the
first place).

I propose introducing a new mm_populate() function to do this pte
population work after the mmap_sem has been released.  mm_populate()
does need to acquire the mmap_sem read side, but critically, it doesn't
need to hold it continuously for the entire duration of the operation -
it can drop it whenever things take too long (such as when hitting disk
for a file read) and re-acquire it later on.

The following patches are included

- Patches 1 fixes some issues I noticed while working on the existing code.
  If needed, they could potentially go in before the rest of the patches.

- Patch 2 introduces the new mm_populate() function and changes
  mmap_region() call sites to use it after they drop mmap_sem. This is
  inspired from Andy Lutomirski's proposal and is built as an extension
  of the work I had previously done for mlock() and mlockall() around
  v2.6.38-rc1. I had tried doing something similar at the time but had
  given up as there were so many do_mmap() call sites; the recent cleanups
  by Linus and Viro are a tremendous help here.

- Patches 3-5 convert some of the less-obvious places doing unbounded
  pte populates to the new mm_populate() mechanism.

- Patches 6-7 are code cleanups that are made possible by the
  mm_populate() work. In particular, they remove more code than the
  entire patch series added, which should be a good thing :)

- Patch 8 is optional to this entire series. It only helps to deal more
  nicely with racy userspace programs that might modify their mappings
  while we're trying to populate them. It adds a new VM_POPULATE flag
  on the mappings we do want to populate, so that if userspace replaces
  them with mappings it doesn't want populated, mm_populate() won't
  populate those replacement mappings.

This patch:

Assorted small fixes. The first two are quite small:

- Move check for vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR)
  within existing if (!(vma->vm_flags & VM_NONLINEAR)) block.
  Purely cosmetic.

- In the VM_LOCKED case, when dropping PG_Mlocked for the over-mapped
  range, make sure we own the mmap_sem write lock around the
  munlock_vma_pages_range call as this manipulates the vma's vm_flags.

Last fix requires a longer explanation. remap_file_pages() can do its work
either through VM_NONLINEAR manipulation or by creating extra vmas.
These two cases were inconsistent with each other (and ultimately, both wrong)
as to exactly when did they fault in the newly mapped file pages:

- In the VM_NONLINEAR case, new file pages would be populated if
  the MAP_NONBLOCK flag wasn't passed. If MAP_NONBLOCK was passed,
  new file pages wouldn't be populated even if the vma is already
  marked as VM_LOCKED.

- In the linear (emulated) case, the work is passed to the mmap_region()
  function which would populate the pages if the vma is marked as
  VM_LOCKED, and would not otherwise - regardless of the value of the
  MAP_NONBLOCK flag, because MAP_POPULATE wasn't being passed to
  mmap_region().

The desired behavior is that we want the pages to be populated and locked
if the vma is marked as VM_LOCKED, or to be populated if the MAP_NONBLOCK
flag is not passed to remap_file_pages().

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: avoid calling pgdat_balanced() needlessly

Now that balance_pgdat() is slightly tidied up, thanks to more capable
pgdat_balanced(), it's become obvious that pgdat_balanced() is called to
check the status, then break the loop if pgdat is balanced, just to be
immediately called again.  The second call is completely unnecessary, of
course.

The patch introduces pgdat_is_balanced boolean, which helps resolve the
above suboptimal behavior, with the added benefit of slightly better
documenting one other place in the function where we jump and skip lots
of code.

Signed-off-by: Zlatko Calusic <zlatko.calusic@iskon.hr>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: compaction: make __compact_pgdat() and compact_pgdat() return void

These functions always return 0.  Formalise this.

Cc: Jason Liu <r64343@freescale.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: make madvise(MADV_WILLNEED) support swap file prefetch

Make madvise(MADV_WILLNEED) support swap file prefetch.  If memory is
swapout, this syscall can do swapin prefetch.  It has no impact if the
memory isn't swapout.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]
[sasha.levin@oracle.com: fix BUG on madvise early failure]
Signed-off-by: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg,vmscan: do not break out targeted reclaim without reclaimed pages

Targeted (hard resp soft) reclaim has traditionally tried to scan one
group with decreasing priority until nr_to_reclaim (SWAP_CLUSTER_MAX
pages) is reclaimed or all priorities are exhausted.  The reclaim is
then retried until the limit is met.

This approach, however, doesn't work well with deeper hierarchies where
groups higher in the hierarchy do not have any or only very few pages
(this usually happens if those groups do not have any tasks and they
have only re-parented pages after some of their children is removed).
Those groups are reclaimed with decreasing priority pointlessly as there
is nothing to reclaim from them.

An easiest fix is to break out of the memcg iteration loop in
shrink_zone only if the whole hierarchy has been visited or sufficient
pages have been reclaimed.  This is also more natural because the
reclaimer expects that the hierarchy under the given root is reclaimed.
As a result we can simplify the soft limit reclaim which does its own
iteration.

[yinghan@google.com: break out of the hierarchy loop only if nr_reclaimed exceeded nr_to_reclaim]
[akpm@linux-foundation.org: use conventional comparison order]
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Ying Han <yinghan@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/ksm.c: use new hashtable implementation

Switch ksm to use the new hashtable implementation.  This reduces the
amount of generic unrelated code in the ksm module.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c: use new hashtable implementation

Switch hugemem to use the new hashtable implementation.  This reduces
the amount of generic unrelated code in the hugemem.

This also removes the dymanic allocation of the hash table.  The upside
is that we save a pointer dereference when accessing the hashtable, but
we lose 8KB if CONFIG_TRANSPARENT_HUGEPAGE is enabled but the processor
doesn't support hugepages.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: compaction: do not accidentally skip pageblocks in the migrate scanner

Compaction uses the ALIGN macro incorrectly with the migrate scanner by
adding pageblock_nr_pages to a PFN.  It happened to work when initially
implemented as the starting PFN was also aligned but with caching
restarts and isolating in smaller chunks this is no longer always true.

The impact is that the migrate scanner scans outside its current
pageblock.  As pfn_valid() is still checked properly it does not cause
any failure and the impact of the bug is that in some cases it will scan
more than necessary when it crosses a page boundary but by no more than
COMPACT_CLUSTER_MAX.  It is highly unlikely this is even measurable but
it's still wrong so this patch addresses the problem.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c:__zone_reclaim(): replace max_t() with max()

"mm: vmscan: save work scanning (almost) empty LRU lists" made
SWAP_CLUSTER_MAX an unsigned long.

Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c:__setup_per_zone_wmarks: make min_pages unsigned long

`int' is an inappropriate type for a number-of-pages counter.

While we're there, use the clamp() macro.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: reduce rmap overhead for ex-KSM page copies created on swap faults

When ex-KSM pages are faulted from swap cache, the fault handler is not
capable of re-establishing anon_vma-spanning KSM pages.  In this case, a
copy of the page is created instead, just like during a COW break.

These freshly made copies are known to be exclusive to the faulting VMA
and there is no reason to go look for this page in parent and sibling
processes during rmap operations.

Use page_add_new_anon_rmap() for these copies.  This also puts them on
the proper LRU lists and marks them SwapBacked, so we can get rid of
doing this ad-hoc in the KSM copy code.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: compaction works against zones, not lruvecs

The restart logic for when reclaim operates back to back with compaction
is currently applied on the lruvec level.  But this does not make sense,
because the container of interest for compaction is a zone as a whole,
not the zone pages that are part of a certain memory cgroup.

Negative impact is bounded.  For one, the code checks that the lruvec
has enough reclaim candidates, so it does not risk getting stuck on a
condition that can not be fulfilled.  And the unfairness of hammering on
one particular memory cgroup to make progress in a zone will be
amortized by the round robin manner in which reclaim goes through the
memory cgroups.  Still, this can lead to unnecessary allocation
latencies when the code elects to restart on a hard to reclaim or small
group when there are other, more reclaimable groups in the zone.

Move this logic to the zone level and restart reclaim for all memory
cgroups in a zone when compaction requires more free pages from it.

[akpm@linux-foundation.org: no need for min_t]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: clean up get_scan_count()

Reclaim pressure balance between anon and file pages is calculated
through a tuple of numerators and a shared denominator.

Exceptional cases that want to force-scan anon or file pages configure
the numerators and denominator such that one list is preferred, which is
not necessarily the most obvious way:

    fraction[0] = 1;
    fraction[1] = 0;
    denominator = 1;
    goto out;

Make this easier by making the force-scan cases explicit and use the
fractionals only in case they are calculated from reclaim history.

[akpm@linux-foundation.org: avoid using unintialized_var()]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: improve comment on low-page cache handling

Fix comment style and elaborate on why anonymous memory is force-scanned
when file cache runs low.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: clarify how swappiness, highest priority, memcg interact

A swappiness of 0 has a slightly different meaning for global reclaim
(may swap if file cache really low) and memory cgroup reclaim (never
swap, ever).

In addition, global reclaim at highest priority will scan all LRU lists
equal to their size and ignore other balancing heuristics.  UNLESS
swappiness forbids swapping, then the lists are balanced based on recent
reclaim effectiveness.  UNLESS file cache is running low, then anonymous
pages are force-scanned.

This (total mess of a) behaviour is implicit and not obvious from the
way the code is organized.  At least make it apparent in the code flow
and document the conditions.  It will be it easier to come up with sane
semantics later.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Satoru Moriya <satoru.moriya@hds.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: save work scanning (almost) empty LRU lists

In certain cases (kswapd reclaim, memcg target reclaim), a fixed minimum
amount of pages is scanned from the LRU lists on each iteration, to make
progress.

Do not make this minimum bigger than the respective LRU list size,
however, and save some busy work trying to isolate and reclaim pages
that are not there.

Empty LRU lists are quite common with memory cgroups in NUMA
environments because there exists a set of LRU lists for each zone for
each memory cgroup, while the memory of a single cgroup is expected to
stay on just one node.  The number of expected empty LRU lists is thus

  memcgs * (nodes - 1) * lru types

Each attempt to reclaim from an empty LRU list does expensive size
comparisons between lists, acquires the zone's lru lock etc.  Avoid
that.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: only evict file pages when we have plenty

Commit e9868505987a ("mm, vmscan: only evict file pages when we have
plenty") makes a point of not going for anonymous memory while there is
still enough inactive cache around.

The check was added only for global reclaim, but it is just as useful to
reduce swapping in memory cgroup reclaim:

    200M-memcg-defconfig-j2

                                     vanilla                   patched
    Real time              454.06 (  +0.00%)         453.71 (  -0.08%)
    User time              668.57 (  +0.00%)         668.73 (  +0.02%)
    System time            128.92 (  +0.00%)         129.53 (  +0.46%)
    Swap in               1246.80 (  +0.00%)         814.40 ( -34.65%)
    Swap out              1198.90 (  +0.00%)         827.00 ( -30.99%)
    Pages allocated   16431288.10 (  +0.00%)    16434035.30 (  +0.02%)
    Major faults           681.50 (  +0.00%)         593.70 ( -12.86%)
    THP faults             237.20 (  +0.00%)         242.40 (  +2.18%)
    THP collapse           241.20 (  +0.00%)         248.50 (  +3.01%)
    THP splits             157.30 (  +0.00%)         161.40 (  +2.59%)

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

CMA: make putback_lru_pages() call conditional

As per documentation and other places calling putback_lru_pages(),
putback_lru_pages() is called on error only.  Make the CMA code behave
consistently.

[akpm@linux-foundation.org: remove a test-n-branch in the wrapup code]
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c: convert to pr_foo()

Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c: convert printk(KERN_FOO) to pr_foo()

Acked-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg, oom: provide more precise dump info while memcg oom happening

Currently when a memcg oom is happening the oom dump messages is still
global state and provides few useful info for users.  This patch prints
more pointed memcg page statistics for memcg-oom and take hierarchy into
consideration:

Based on Michal's advice, we take hierarchy into consideration: supppose
we trigger an OOM on A's limit

        root_memcg
            |
            A (use_hierachy=1)
           / \
          B   C
          |
          D
then the printed info will be:

  Memory cgroup stats for /A:...
  Memory cgroup stats for /A/B:...
  Memory cgroup stats for /A/C:...
  Memory cgroup stats for /A/B/D:...

Following are samples of oom output:

(1) Before change:

    mal-80 invoked oom-killer:gfp_mask=0xd0, order=0, oom_score_adj=0
    mal-80 cpuset=/ mems_allowed=0
    Pid: 2976, comm: mal-80 Not tainted 3.7.0+ #10
    Call Trace:
     [<ffffffff8167fbfb>] dump_header+0x83/0x1ca
     ..... (call trace)
     [<ffffffff8168a818>] page_fault+0x28/0x30
                             <<<<<<<<<<<<<<<<<<<<< memcg specific information
    Task in /A/B/D killed as a result of limit of /A
    memory: usage 101376kB, limit 101376kB, failcnt 57
    memory+swap: usage 101376kB, limit 101376kB, failcnt 0
    kmem: usage 0kB, limit 9007199254740991kB, failcnt 0
                             <<<<<<<<<<<<<<<<<<<<< print per cpu pageset stat
    Mem-Info:
    Node 0 DMA per-cpu:
    CPU    0: hi:    0, btch:   1 usd:   0
    ......
    CPU    3: hi:    0, btch:   1 usd:   0
    Node 0 DMA32 per-cpu:
    CPU    0: hi:  186, btch:  31 usd: 173
    ......
    CPU    3: hi:  186, btch:  31 usd: 130
                             <<<<<<<<<<<<<<<<<<<<< print global page state
    active_anon:92963 inactive_anon:40777 isolated_anon:0
     active_file:33027 inactive_file:51718 isolated_file:0
     unevictable:0 dirty:3 writeback:0 unstable:0
     free:729995 slab_reclaimable:6897 slab_unreclaimable:6263
     mapped:20278 shmem:35971 pagetables:5885 bounce:0
     free_cma:0
                             <<<<<<<<<<<<<<<<<<<<< print per zone page state
    Node 0 DMA free:15836kB ... all_unreclaimable? no
    lowmem_reserve[]: 0 3175 3899 3899
    Node 0 DMA32 free:2888564kB ... all_unrelaimable? no
    lowmem_reserve[]: 0 0 724 724
    lowmem_reserve[]: 0 0 0 0
    Node 0 DMA: 1*4kB (U) ... 3*4096kB (M) = 15836kB
    Node 0 DMA32: 41*4kB (UM) ... 702*4096kB (MR) = 2888316kB
    120710 total pagecache pages
    0 pages in swap cache
                             <<<<<<<<<<<<<<<<<<<<< print global swap cache stat
    Swap cache stats: add 0, delete 0, find 0/0
    Free swap  = 499708kB
    Total swap = 499708kB
    1040368 pages RAM
    58678 pages reserved
    169065 pages shared
    173632 pages non-shared
    [ pid ]   uid  tgid total_vm      rss nr_ptes swapents oom_score_adj name
    [ 2693]     0  2693     6005     1324      17        0             0 god
    [ 2754]     0  2754     6003     1320      16        0             0 god
    [ 2811]     0  2811     5992     1304      18        0             0 god
    [ 2874]     0  2874     6005     1323      18        0             0 god
    [ 2935]     0  2935     8720     7742      21        0             0 mal-30
    [ 2976]     0  2976    21520    17577      42        0             0 mal-80
    Memory cgroup out of memory: Kill process 2976 (mal-80) score 665 or sacrifice child
    Killed process 2976 (mal-80) total-vm:86080kB, anon-rss:69964kB, file-rss:344kB

We can see that messages dumped by show_free_areas() are longsome and can
provide so limited info for memcg that just happen oom.

(2) After change
    mal-80 invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0
    mal-80 cpuset=/ mems_allowed=0
    Pid: 2704, comm: mal-80 Not tainted 3.7.0+ #10
    Call Trace:
     [<ffffffff8167fd0b>] dump_header+0x83/0x1d1
     .......(call trace)
     [<ffffffff8168a918>] page_fault+0x28/0x30
    Task in /A/B/D killed as a result of limit of /A
                             <<<<<<<<<<<<<<<<<<<<< memcg specific information
    memory: usage 102400kB, limit 102400kB, failcnt 140
    memory+swap: usage 102400kB, limit 102400kB, failcnt 0
    kmem: usage 0kB, limit 9007199254740991kB, failcnt 0
    Memory cgroup stats for /A: cache:32KB rss:30984KB mapped_file:0KB swap:0KB inactive_anon:6912KB active_anon:24072KB inactive_file:32KB active_file:0KB unevictable:0KB
    Memory cgroup stats for /A/B: cache:0KB rss:0KB mapped_file:0KB swap:0KB inactive_anon:0KB active_anon:0KB inactive_file:0KB active_file:0KB unevictable:0KB
    Memory cgroup stats for /A/C: cache:0KB rss:0KB mapped_file:0KB swap:0KB inactive_anon:0KB active_anon:0KB inactive_file:0KB active_file:0KB unevictable:0KB
    Memory cgroup stats for /A/B/D: cache:32KB rss:71352KB mapped_file:0KB swap:0KB inactive_anon:6656KB active_anon:64696KB inactive_file:16KB active_file:16KB unevictable:0KB
    [ pid ]   uid  tgid total_vm      rss nr_ptes swapents oom_score_adj name
    [ 2260]     0  2260     6006     1325      18        0             0 god
    [ 2383]     0  2383     6003     1319      17        0             0 god
    [ 2503]     0  2503     6004     1321      18        0             0 god
    [ 2622]     0  2622     6004     1321      16        0             0 god
    [ 2695]     0  2695     8720     7741      22        0             0 mal-30
    [ 2704]     0  2704    21520    17839      43        0             0 mal-80
    Memory cgroup out of memory: Kill process 2704 (mal-80) score 669 or sacrifice child
    Killed process 2704 (mal-80) total-vm:86080kB, anon-rss:71016kB, file-rss:340kB

This version provides more pointed info for memcg in "Memory cgroup stats
for XXX" section.

Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/md/persistent-data/dm-transaction-manager.c: rename HASH_SIZE

Fix the warning:

  drivers/md/persistent-data/dm-transaction-manager.c:28:1: warning: "HASH_SIZE" redefined
  In file included from include/linux/elevator.h:5,
                   from include/linux/blkdev.h:216,
                   from drivers/md/persistent-data/dm-block-manager.h:11,
                   from drivers/md/persistent-data/dm-transaction-manager.h:10,
                   from drivers/md/persistent-data/dm-transaction-manager.c:6:
  include/linux/hashtable.h:22:1: warning: this is the location of the previous definition

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'x86-mm-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 mm changes from Peter Anvin:
 "This is a huge set of several partly interrelated (and concurrently
  developed) changes, which is why the branch history is messier than
  one would like.

  The *really* big items are two humonguous patchsets mostly developed
  by Yinghai Lu at my request, which completely revamps the way we
  create initial page tables.  In particular, rather than estimating how
  much memory we will need for page tables and then build them into that
  memory -- a calculation that has shown to be incredibly fragile -- we
  now build them (on 64 bits) with the aid of a "pseudo-linear mode" --
  a #PF handler which creates temporary page tables on demand.

  This has several advantages:

  1. It makes it much easier to support things that need access to data
     very early (a followon patchset uses this to load microcode way
     early in the kernel startup).

  2. It allows the kernel and all the kernel data objects to be invoked
     from above the 4 GB limit.  This allows kdump to work on very large
     systems.

  3. It greatly reduces the difference between Xen and native (Xen's
     equivalent of the #PF handler are the temporary page tables created
     by the domain builder), eliminating a bunch of fragile hooks.

  The patch series also gets us a bit closer to W^X.

  Additional work in this pull is the 64-bit get_user() work which you
  were also involved with, and a bunch of cleanups/speedups to
  __phys_addr()/__pa()."

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits)
  x86, mm: Move reserving low memory later in initialization
  x86, doc: Clarify the use of asm("%edx") in uaccess.h
  x86, mm: Redesign get_user with a __builtin_choose_expr hack
  x86: Be consistent with data size in getuser.S
  x86, mm: Use a bitfield to mask nuisance get_user() warnings
  x86/kvm: Fix compile warning in kvm_register_steal_time()
  x86-32: Add support for 64bit get_user()
  x86-32, mm: Remove reference to alloc_remap()
  x86-32, mm: Remove reference to resume_map_numa_kva()
  x86-32, mm: Rip out x86_32 NUMA remapping code
  x86/numa: Use __pa_nodebug() instead
  x86: Don't panic if can not alloc buffer for swiotlb
  mm: Add alloc_bootmem_low_pages_nopanic()
  x86, 64bit, mm: hibernate use generic mapping_init
  x86, 64bit, mm: Mark data/bss/brk to nx
  x86: Merge early kernel reserve for 32bit and 64bit
  x86: Add Crash kernel low reservation
  x86, kdump: Remove crashkernel range find limit for 64bit
  memblock: Add memblock_mem_size()
  x86, boot: Not need to check setup_header version for setup_data
  ...

Merge branch 'x86-cpu-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 cpu updates from Peter Anvin:
 "This is a corrected attempt at the x86/cpu branch, this time with the
  fixes in that makes it not break on KVM (current or past), or any
  other virtualizer which traps on this configuration.

  Again, the biggest change here is enabling the WC+ memory type on AMD
  processors, if the BIOS doesn't."

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, kvm: Add MSR_AMD64_BU_CFG2 to the list of ignored MSRs
  x86, cpu, amd: Fix WC+ workaround for older virtual hosts
  x86, AMD: Enable WC+ memory type on family 10 processors
  x86, AMD: Clean up init_amd()
  x86/process: Change %8s to %s for pr_warn() in release_thread()
  x86/cpu/hotplug: Remove CONFIG_EXPERIMENTAL dependency

Merge tag 'please-pull-misc-3.9' of git://git./linux/kernel/git/aegl/linux

Pull misc ia64 bits from Tony Luck.

* tag 'please-pull-misc-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  MAINTAINERS: update SGI & ia64 Altix stuff
  sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

Merge branch 'for-linus' of git://git./linux/kernel/git/s390/linux

Pull s390 update from Martin Schwidefsky:
 "The most prominent change in this patch set is the software dirty bit
  patch for s390.  It removes __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY and
  the page_test_and_clear_dirty primitive which makes the common memory
  management code a bit less obscure.

  Heiko fixed most of the PCI related fallout, more often than not
  missing GENERIC_HARDIRQS dependencies.  Notable is one of the 3270
  patches which adds an export to tty_io to be able to resize a tty.

  The rest is the usual bunch of cleanups and bug fixes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits)
  s390/module: Add missing R_390_NONE relocation type
  drivers/gpio: add missing GENERIC_HARDIRQ dependency
  drivers/input: add couple of missing GENERIC_HARDIRQS dependencies
  s390/cleanup: rename SPP to LPP
  s390/mm: implement software dirty bits
  s390/mm: Fix crst upgrade of mmap with MAP_FIXED
  s390/linker skript: discard exit.data at runtime
  drivers/media: add missing GENERIC_HARDIRQS dependency
  s390/bpf,jit: add vlan tag support
  drivers/net,AT91RM9200: add missing GENERIC_HARDIRQS dependency
  iucv: fix kernel panic at reboot
  s390/Kconfig: sort list of arch selected config options
  phylib: remove !S390 dependeny from Kconfig
  uio: remove !S390 dependency from Kconfig
  dasd: fix sysfs cleanup in dasd_generic_remove
  s390/pci: fix hotplug module init
  s390/pci: cleanup clp page allocation
  s390/pci: cleanup clp inline assembly
  s390/perf: cpum_cf: fallback to software sampling events
  s390/mm: provide PAGE_SHARED define
  ...

Merge branch 'for-linus' of git://git./linux/kernel/git/jikos/hid

Pull HID subsystem updates from Jiri Kosina:
 "HID subsystem and drivers update. Highlights:

   - new support of a group of Win7/Win8 multitouch devices, from
     Benjamin Tissoires

   - fix for compat interface brokenness in uhid, from Dmitry Torokhov

   - conversion of drivers to use hid_driver helper, by H Hartley
     Sweeten

   - HID over I2C transport received ACPI enumeration support, written
     by Mika Westerberg

   - there is an ongoing effort to make HID sensor hubs independent of
     USB transport.  The first self-contained part of this work is
     provided here, done by Mika Westerberg

   - a few smaller fixes here and there, support for a couple new
     devices added"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (43 commits)
  HID: Correct Logitech order in hid-ids.h
  HID: LG4FF: Remove unnecessary deadzone code
  HID: LG: Prevent the Logitech Gaming Wheels deadzone
  HID: LG: Fix detection of Logitech Speed Force Wireless (WiiWheel)
  HID: LG: Add support for Logitech Momo Force (Red) Wheel
  HID: hidraw: print message when succesfully initialized
  HID: logitech: split accel, brake for Driving Force wheel
  HID: logitech: add report descriptor for Driving Force wheel
  HID: add ThingM blink(1) USB RGB LED support
  HID: uhid: make creating devices work on 64/32 systems
  HID: wiimote: fix nunchuck button parser
  HID: blacklist Velleman data acquisition boards
  HID: sensor-hub: don't limit the driver only to USB bus
  HID: sensor-hub: get rid of unused sensor_hub_grabbed_usages[] table
  HID: extend autodetect to handle I2C sensors as well
  HID: ntrig: use input_configured() callback to set the name
  HID: multitouch: do not use pointers towards hid-core
  HID: add missing GENERIC_HARDIRQ dependency
  HID: multitouch: make MT_CLS_ALWAYS_TRUE the new default class
  HID: multitouch: fix protocol for Elo panels
  ...

Merge branch 'for-linus' of git://git./linux/kernel/git/jikos/trivial

Pull trivial tree from Jiri Kosina:
 "Assorted tiny fixes queued in trivial tree"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (22 commits)
  DocBook: update EXPORT_SYMBOL entry to point at export.h
  Documentation: update top level 00-INDEX file with new additions
  ARM: at91/ide: remove unsused at91-ide Kconfig entry
  percpu_counter.h: comment code for better readability
  x86, efi: fix comment typo in head_32.S
  IB: cxgb3: delay freeing mem untill entirely done with it
  net: mvneta: remove unneeded version.h include
  time: x86: report_lost_ticks doesn't exist any more
  pcmcia: avoid static analysis complaint about use-after-free
  fs/jfs: Fix typo in comment : 'how may' -> 'how many'
  of: add missing documentation for of_platform_populate()
  btrfs: remove unnecessary cur_trans set before goto loop in join_transaction
  sound: soc: Fix typo in sound/codecs
  treewide: Fix typo in various drivers
  btrfs: fix comment typos
  Update ibmvscsi module name in Kconfig.
  powerpc: fix typo (utilties -> utilities)
  of: fix spelling mistake in comment
  h8300: Fix home page URL in h8300/README
  xtensa: Fix home page URL in Kconfig
  ...

Merge branch 'akpm' (incoming from Andrew)

Merge misc patches from Andrew Morton:

 - Florian has vanished so I appear to have become fbdev maintainer
   again :(

 - Joel and Mark are distracted to welcome to the new OCFS2 maintainer

 - The backlight queue

 - Small core kernel changes

 - lib/ updates

 - The rtc queue

 - Various random bits

* akpm: (164 commits)
  rtc: rtc-davinci: use devm_*() functions
  rtc: rtc-max8997: use devm_request_threaded_irq()
  rtc: rtc-max8907: use devm_request_threaded_irq()
  rtc: rtc-da9052: use devm_request_threaded_irq()
  rtc: rtc-wm831x: use devm_request_threaded_irq()
  rtc: rtc-tps80031: use devm_request_threaded_irq()
  rtc: rtc-lp8788: use devm_request_threaded_irq()
  rtc: rtc-coh901331: use devm_clk_get()
  rtc: rtc-vt8500: use devm_*() functions
  rtc: rtc-tps6586x: use devm_request_threaded_irq()
  rtc: rtc-imxdi: use devm_clk_get()
  rtc: rtc-cmos: use dev_warn()/dev_dbg() instead of printk()/pr_debug()
  rtc: rtc-pcf8583: use dev_warn() instead of printk()
  rtc: rtc-sun4v: use pr_warn() instead of printk()
  rtc: rtc-vr41xx: use dev_info() instead of printk()
  rtc: rtc-rs5c313: use pr_err() instead of printk()
  rtc: rtc-at91rm9200: use dev_dbg()/dev_err() instead of printk()/pr_debug()
  rtc: rtc-rs5c372: use dev_dbg()/dev_warn() instead of printk()/pr_debug()
  rtc: rtc-ds2404: use dev_err() instead of printk()
  rtc: rtc-efi: use dev_err()/dev_warn()/pr_err() instead of printk()
  ...

rtc: rtc-davinci: use devm_*() functions

Use devm_*() functions to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-max8997: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-max8907: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-da9052: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-wm831x: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-tps80031: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-lp8788: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-coh901331: use devm_clk_get()

Use devm_clk_get() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-vt8500: use devm_*() functions

Use devm_*() functions to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-tps6586x: use devm_request_threaded_irq()

Use devm_request_threaded_irq() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-imxdi: use devm_clk_get()

Use devm_clk_get() to make cleanup paths more simple.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-cmos: use dev_warn()/dev_dbg() instead of printk()/pr_debug()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-pcf8583: use dev_warn() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-sun4v: use pr_warn() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-vr41xx: use dev_info() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-rs5c313: use pr_err() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-at91rm9200: use dev_dbg()/dev_err() instead of printk()/pr_debug()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-rs5c372: use dev_dbg()/dev_warn() instead of printk()/pr_debug()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-ds2404: use dev_err() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: rtc-efi: use dev_err()/dev_warn()/pr_err() instead of printk()

Fix the checkpatch warnings as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...
  WARNING: please, no space before tabs

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: max77686: use dev_info() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: use dev_warn()/dev_dbg()/pr_err() instead of printk()

Fix the checkpatch warning as below:

  WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-sa1100.c: move clock enable/disable to probe/remove

The original sa1100_rtc_open/sa1100_rtc_release will be called when the
/dev/rtc0 is opened or closed.  In fact, these two functions will
enable/disable the clock.  Disabling clock will make rtc not work.  So
only enable/disable clock when probe/remove the device.

Signed-off-by: Chao Xie <chao.xie@marvell.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: max8997: add driver for max8997 rtc

Add an rtc driver for Maxim 8997 multifunction chip.  Max8997 has rtc
module in it.  and it can be used for timekeeping clock and system alarm.
It provide various operational mode those are BCD/binary, 24/12hour,
am/pm.  Driver sets binary/24/ for default.  Maxim 8997 also supports
SMPL(Sudden Momentary Power Loss), WTSR (Watchdog Timeout and Software
Reset).

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Cc: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-s3c.c: use dev_dbg() instaed of pr_debug()

Use dev_dbg() instaed of pr_debug() to be consistent.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm: mvebu: add RTC support for Armada 370 and Armada XP

The Armada 370 and Armada XP Socs have the same controller that the one
used in the orion platforms.  This patch updates the device tree for
these SoCs.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-pl031.c: add wakeup support

Mark the pl031 as wake-up capable so that rtcwake and suspend test can work.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: add support for spi rtc rx4581

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Torben Hohn <torbenh@linutronix.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-tps65910.c: set irq flag to IRQF_EARLY_RESUME during irq request

All interrupt get disabled during system suspend and enabled during system
resume.  The enabling/disabling of interrupt happen in sequence of
interrupt registration with framework.

Therefore, in resume, the parent interrupt of this device enabled before
the RTC irq interrupt enabled.  If RTC is enabled for alarm wake and if
system wake by alarm then there is interrupt pending for RTC.  In resume,
the parent interrupt get enabled before the rtc interrupt and hence ISR
get served.  In ISR, it founds that rtc interrupt is disabled and so it
does not call the rtc isr handler and hence it misses the interrupt.

Setting flag for early resume so that rtc interrupt get enabled before
parent interrupt and so rtc interrupt get enabled when parent interrupt
handler check for interrupt of device and call the rtc handler if it is
there.  This way it will not miss the interrupt.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-tps65910.c: use sleep_pm_ops macro for initialising suspend/resume callbacks

Use SET_SYSTEM_SLEEP_PM_OPS for setting suspend/resume callbacks for
dev_pm_ops.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-tps65910.c: remove unnecessary irq stat save and restore

The driver stores the interrupt enable register before going to suspend
and restore in resume.  Also it enables alarm before going to suspend.

The driver only write the Interrupt enable register for enabling ALARM and
does not enable any other bits.  So it is not require to save complete
register and enable ALARM interrupt before suspend and restore in resume.

Also ALARM interrupt already enable if alarm is enabled before going to
suspend and hence it is not require to enable explictly in suspend.

Removing such above code.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-tps65910.c: enable/disable wake in suspend/resume

Making the rtc driver as wakeup capabale and leaving the wake
enable/disable decision to user space through a sysfs attribute.

In suspend, enable wake if device wakeup enabled.  In resume disable wake
again.

This change is inline with the Documentation/power/devices.txt#
/sys/devices/.../power/wakeup files

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: add RTC driver for TPS80031/TPS80032

Add an RTC driver for TPS80031/TPS80032 chips by TI.  This driver
supports:
 - Setting and getting time and date.
 - Setting and reading alarm time.
 - Alarm and interrupt functionlity.

[akpm@linux-foundation.org: remove obsolete __devinit/__devexit]
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: add new lp8788 rtc driver

TI LP8788 PMU supports regulators, battery charger, RTC, ADC, backlight
driver and current sinks.  This patch enables LP8788 rtc module.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ds2404.c: use module_platform_driver macro

Remove removes some code duplication by using module_platform_driver().

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc: remove unnecessary semicolons

Found by Coccinelle: http://coccinelle.lip6.fr/

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-pxa.c: avoid cpuid checking

pxa-rtc is widely used in pxa27x/pxa3xx/pxa93x/pxa95x. Checking cpuid in
pxa-rtc driver is unnecessary since we assign on-chip device in soc files.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc: use of_match_ptr() macro

This eliminates having an #ifdef returning NULL for the case when OF is
disabled.  Maintains consistency in cases where OF is always selected.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc-pcf8523: add low battery voltage support

Implement reading of the battery voltage low signal for rtc-pcf8523.

The bit is read-only and cannot be cleared by software, so no
clear function is implemented.

[akpm@linux-foundation.org: omit pcf8563_rtc_ioctl() if CONFIG_RTC_INTF_DEV=n]
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: max77686: add Maxim 77686 driver

Add a driver to support max77686 rtc.  MAX77686 rtc support smpl and wtsr
mode.  It has two alarm register which can be used for alarming to wake
system up.  This drvier uses regmap to access its register.

[akpm@linux-foundation.org: remove inline, __devinit annotations]
[jg1.han@samsung.com: fix build warnings]
[akpm@linux-foundation.org: simplify code]
Signed-off-by: Chiwoong Byun <woong.byun@samsung.com>
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Myugnjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-pxa.c: fix alarm can't wake up system issue

Fix alarm can't wake up system issue

Signed-off-by: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-pxa.c: fix alarm not match issue

Fix pxa rtc alarm issue by setting week of month and day of week in
rdar/rdcr or it would not match.

Signed-off-by: Leo Song <liangs@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc: dump small buffers via %*ph

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/nsproxy.c: remove duplicate task_cred_xxx for user_ns

We can use user_ns, which is also assigned from task_cred_xxx(tsk,
user_ns), at the beginning of copy_namespaces().

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

binfmt_elf: remove unused argument in fill_elf_header

In fill_elf_header(), elf->e_ident[EI_OSABI] is always set to ELF_OSABI,
so remove the unused argument 'osabi'.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix USLEEP_RANGE test

Do not test udelay() for a value less than 10usec when passed a variable
instead of a hard-coded number; there is no way for checkpatch to know the
value of the variable.  As it is today, it will complain about variables
with alphanumeric characters plus '_', e.g.  foo_bar, but not variables
with other characters, eg.  foo->bar.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: Add check for kcalloc argument order

kcalloc is sometimes misused with the first and second arguments switched.

Same issue with kmalloc_array too.

Bleat if sizeof is the first argument

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: don't emit the CamelCase warning for PageFoo

I'm getting a ton of these:

  WARNING: Avoid CamelCase: <PageTransHuge>
  #140: FILE: mm/migrate.c:1576:
  +       if (PageTransHuge(page) && page_count(page) != 3) {

So exclude anything which starts with "Page".

Tested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: add Joe to MAINTAINERS

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: warn on unnecessary __dev<foo> section markings

Get people to stop adding __devinit and __devexit section markings.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: prefer dev_<level>( to dev_printk(KERN_<LEVEL>

Add YA check to printk style.

dev_<level> uses are functions and generate smaller
object code than dev_printk(KERN_<LEVEL>.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

decompressors: make the default XZ_DEC_* config match the selected architecture

Change the defautl XZ_DEC_* config symbol to match the configured
architecture.  It is perfectly legitimate to support multiple XZ BCJ
filters for different architectures (e.g.: to mount foreign squashfs/xz
compressed filesystems), it is however more natural not to select them all
by default, but only the one matching the configured architecture.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

decompressors: drop dependency on CONFIG_EXPERT

Remove the XZ_DEC_* depedencey on CONFIG_EXPERT as recommended by Lasse
Colin.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

decompressors: group XZ_DEC_* symbols under an if XZ_BCJ / endif

Group all architecture-specific BCJ filter configuration symbols under an
if XZ_BCJ / endif statement.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>