Commit 38c5ce93 ("mm/gup: Replace ACCESS_ONCE with READ_ONCE")
converted ACCESS_ONCE usage in gup_pmd_range() to READ_ONCE, since
ACCESS_ONCE doesn't work reliably on non-scalar types.

This patch also fixes the other ACCESS_ONCE usages in gup_pte_range()
and __get_user_pages_fast() in mm/gup.c
Signed-off-by: NJason Low <jason.low2@hp.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NDavidlohr Bueso <dave@stgolabs.net>
Acked-by: NRik van Riel <riel@redhat.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As suggested by Kirill the "goto"s in vma_to_resize aren't necessary, just
change them to explicit return.
Signed-off-by: NDerek Che <crquan@ymail.com>
Suggested-by: N"Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recently I straced bash behavior in this dd zero pipe to read test, in
part of testing under vm.overcommit_memory=2 (OVERCOMMIT_NEVER mode):

    # dd if=/dev/zero | read x

The bash sub shell is calling mremap to reallocate more and more memory
untill it finally failed -ENOMEM (I expect), or to be killed by system OOM
killer (which should not happen under OVERCOMMIT_NEVER mode); But the
mremap system call actually failed of -EFAULT, which is a surprise to me,
I think it's supposed to be -ENOMEM?  then I wrote this piece of C code
testing confirmed it: https://gist.github.com/crquan/326bde37e1ddda8effe5

    $ ./remap
    allocated one page @0x7f686bf71000, (PAGE_SIZE: 4096)
    grabbed 7680512000 bytes of memory (1875125 pages) @ 00007f6690993000.
    mremap failed Bad address (14).

The -EFAULT comes from the branch of security_vm_enough_memory_mm failure,
underlyingly it calls __vm_enough_memory which returns only 0 for success
or -ENOMEM; So why vma_to_resize needs to return -EFAULT in this case?
this sounds like a mistake to me.

Some more digging into git history:

1) Before commit 119f657c ("RLIMIT_AS checking fix") in May 1 2005
   (pre 2.6.12 days) it was returning -ENOMEM for this failure;

2) but commit 119f657c ("untangling do_mremap(), part 1") changed it
   accidentally, to what ever is preserved in local ret, which happened to
   be -EFAULT, in a previous assignment;

3) then in commit 54f5de70 code refactoring, it's explicitly returning
   -EFAULT, should be wrong.
Signed-off-by: NDerek Che <crquan@ymail.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In original implementation of vm_map_ram made by Nick Piggin there were
two bitmaps: alloc_map and dirty_map.  None of them were used as supposed
to be: finding a suitable free hole for next allocation in block.
vm_map_ram allocates space sequentially in block and on free call marks
pages as dirty, so freed space can't be reused anymore.

Actually it would be very interesting to know the real meaning of those
bitmaps, maybe implementation was incomplete, etc.

But long time ago Zhang Yanfei removed alloc_map by these two commits:

  mm/vmalloc.c: remove dead code in vb_alloc
     3fcd76e8
  mm/vmalloc.c: remove alloc_map from vmap_block
     b8e748b6

In this patch I replaced dirty_map with two range variables: dirty min and
max.  These variables store minimum and maximum position of dirty space in
a block, since we need only to know the dirty range, not exact position of
dirty pages.

Why it was made?  Several reasons: at first glance it seems that
vm_map_ram allocator concerns about fragmentation thus it uses bitmaps for
finding free hole, but it is not true.  To avoid complexity seems it is
better to use something simple, like min or max range values.  Secondly,
code also becomes simpler, without iteration over bitmap, just comparing
values in min and max macros.  Thirdly, bitmap occupies up to 1024 bits
(4MB is a max size of a block).  Here I replaced the whole bitmap with two
longs.

Finally vm_unmap_aliases should be slightly faster and the whole
vmap_block structure occupies less memory.
Signed-off-by: NRoman Pen <r.peniaev@gmail.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christoph Lameter <cl@linux.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: Rob Jones <rob.jones@codethink.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Previous implementation allocates new vmap block and repeats search of a
free block from the very beginning, iterating over the CPU free list.

Why it can be better??

1. Allocation can happen on one CPU, but search can be done on another CPU.
   In worst case we preallocate amount of vmap blocks which is equal to
   CPU number on the system.

2. In previous patch I added newly allocated block to the tail of free list
   to avoid soon exhaustion of virtual space and give a chance to occupy
   blocks which were allocated long time ago.  Thus to find newly allocated
   block all the search sequence should be repeated, seems it is not efficient.

In this patch newly allocated block is occupied right away, address of
virtual space is returned to the caller, so there is no any need to repeat
the search sequence, allocation job is done.
Signed-off-by: NRoman Pen <r.peniaev@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christoph Lameter <cl@linux.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: Rob Jones <rob.jones@codethink.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recently I came across high fragmentation of vm_map_ram allocator:
vmap_block has free space, but still new blocks continue to appear.
Further investigation showed that certain mapping/unmapping sequences
can exhaust vmalloc space.  On small 32bit systems that's not a big
problem, cause purging will be called soon on a first allocation failure
(alloc_vmap_area), but on 64bit machines, e.g.  x86_64 has 45 bits of
vmalloc space, that can be a disaster.

1) I came up with a simple allocation sequence, which exhausts virtual
   space very quickly:

  while (iters) {

                /* Map/unmap big chunk */
                vaddr = vm_map_ram(pages, 16, -1, PAGE_KERNEL);
                vm_unmap_ram(vaddr, 16);

                /* Map/unmap small chunks.
                 *
                 * -1 for hole, which should be left at the end of each block
                 * to keep it partially used, with some free space available */
                for (i = 0; i < (VMAP_BBMAP_BITS - 16) / 8 - 1; i++) {
                        vaddr = vm_map_ram(pages, 8, -1, PAGE_KERNEL);
                        vm_unmap_ram(vaddr, 8);
                }
  }

The idea behind is simple:

 1. We have to map a big chunk, e.g. 16 pages.

 2. Then we have to occupy the remaining space with smaller chunks, i.e.
    8 pages. At the end small hole should remain to keep block in free list,
    but do not let big chunk to occupy remaining space.

 3. Goto 1 - allocation request of 16 pages can't be completed (only 8 slots
    are left free in the block in the #2 step), new block will be allocated,
    all further requests will lay into newly allocated block.

To have some measurement numbers for all further tests I setup ftrace and
enabled 4 basic calls in a function profile:

        echo vm_map_ram              > /sys/kernel/debug/tracing/set_ftrace_filter;
        echo alloc_vmap_area        >> /sys/kernel/debug/tracing/set_ftrace_filter;
        echo vm_unmap_ram           >> /sys/kernel/debug/tracing/set_ftrace_filter;
        echo free_vmap_block        >> /sys/kernel/debug/tracing/set_ftrace_filter;

So for this scenario I got these results:

BEFORE (all new blocks are put to the head of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  vm_map_ram                          126000    30683.30 us     0.243 us        30819.36 us
  vm_unmap_ram                        126000    22003.24 us     0.174 us        340.886 us
  alloc_vmap_area                       1000    4132.065 us     4.132 us        0.903 us

AFTER (all new blocks are put to the tail of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  vm_map_ram                          126000    28713.13 us     0.227 us        24944.70 us
  vm_unmap_ram                        126000    20403.96 us     0.161 us        1429.872 us
  alloc_vmap_area                        993    3916.795 us     3.944 us        29.370 us
  free_vmap_block                        992    654.157 us      0.659 us        1.273 us

SUMMARY:

The most interesting numbers in those tables are numbers of block
allocations and deallocations: alloc_vmap_area and free_vmap_block
calls, which show that before the change blocks were not freed, and
virtual space and physical memory (vmap_block structure allocations,
etc) were consumed.

Average time which were spent in vm_map_ram/vm_unmap_ram became slightly
better.  That can be explained with a reasonable amount of blocks in a
free list, which we need to iterate to find a suitable free block.

2) Another scenario is a random allocation:

  while (iters) {

                /* Randomly take number from a range [1..32/64] */
                nr = rand(1, VMAP_MAX_ALLOC);
                vaddr = vm_map_ram(pages, nr, -1, PAGE_KERNEL);
                vm_unmap_ram(vaddr, nr);
  }

I chose mersenne twister PRNG to generate persistent random state to
guarantee that both runs have the same random sequence.  For each
vm_map_ram call random number from [1..32/64] was taken to represent
amount of pages which I do map.

I did 10'000 vm_map_ram calls and got these two tables:

BEFORE (all new blocks are put to the head of a free list)

# cat /sys/kernel/debug/tracing/trace_stat/function0
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  vm_map_ram                           10000    10170.01 us     1.017 us        993.609 us
  vm_unmap_ram                         10000    5321.823 us     0.532 us        59.789 us
  alloc_vmap_area                        420    2150.239 us     5.119 us        3.307 us
  free_vmap_block                         37    159.587 us      4.313 us        134.344 us

AFTER (all new blocks are put to the tail of a free list)

# cat /sys/kernel/debug/tracing/trace_stat/function0
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  vm_map_ram                           10000    7745.637 us     0.774 us        395.229 us
  vm_unmap_ram                         10000    5460.573 us     0.546 us        67.187 us
  alloc_vmap_area                        414    2201.650 us     5.317 us        5.591 us
  free_vmap_block                        412    574.421 us      1.394 us        15.138 us

SUMMARY:

'BEFORE' table shows, that 420 blocks were allocated and only 37 were
freed.  Remained 383 blocks are still in a free list, consuming virtual
space and physical memory.

'AFTER' table shows, that 414 blocks were allocated and 412 were really
freed.  2 blocks remained in a free list.

So fragmentation was dramatically reduced.  Why? Because when we put
newly allocated block to the head, all further requests will occupy new
block, regardless remained space in other blocks.  In this scenario all
requests come randomly.  Eventually remained free space will be less
than requested size, free list will be iterated and it is possible that
nothing will be found there - finally new block will be created.  So
exhaustion in random scenario happens for the maximum possible
allocation size: 32 pages for 32-bit system and 64 pages for 64-bit
system.

Also average cost of vm_map_ram was reduced from 1.017 us to 0.774 us.
Again this can be explained by iteration through smaller list of free
blocks.

3) Next simple scenario is a sequential allocation, when the allocation
   order is increased for each block.  This scenario forces allocator to
   reach maximum amount of partially free blocks in a free list:

  while (iters) {

                /* Populate free list with blocks with remaining space */
                for (order = 0; order <= ilog2(VMAP_MAX_ALLOC); order++) {
                        nr = VMAP_BBMAP_BITS / (1 << order);

                        /* Leave a hole */
                        nr -= 1;

                        for (i = 0; i < nr; i++) {
                                vaddr = vm_map_ram(pages, (1 << order), -1, PAGE_KERNEL);
                                vm_unmap_ram(vaddr, (1 << order));
                }

                /* Completely occupy blocks from a free list */
                for (order = 0; order <= ilog2(VMAP_MAX_ALLOC); order++) {
                        vaddr = vm_map_ram(pages, (1 << order), -1, PAGE_KERNEL);
                        vm_unmap_ram(vaddr, (1 << order));
                }
  }

Results which I got:

BEFORE (all new blocks are put to the head of a free list)

# cat /sys/kernel/debug/tracing/trace_stat/function0
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  vm_map_ram                         2032000    399545.2 us     0.196 us        467123.7 us
  vm_unmap_ram                       2032000    363225.7 us     0.178 us        111405.9 us
  alloc_vmap_area                       7001    30627.76 us     4.374 us        495.755 us
  free_vmap_block                       6993    7011.685 us     1.002 us        159.090 us

AFTER (all new blocks are put to the tail of a free list)

# cat /sys/kernel/debug/tracing/trace_stat/function0
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  vm_map_ram                         2032000    394259.7 us     0.194 us        589395.9 us
  vm_unmap_ram                       2032000    292500.7 us     0.143 us        94181.08 us
  alloc_vmap_area                       7000    31103.11 us     4.443 us        703.225 us
  free_vmap_block                       7000    6750.844 us     0.964 us        119.112 us

SUMMARY:

No surprises here, almost all numbers are the same.

Fixing this fragmentation problem I also did some improvements in a
allocation logic of a new vmap block: occupy block immediately and get
rid of extra search in a free list.

Also I replaced dirty bitmap with min/max dirty range values to make the
logic simpler and slightly faster, since two longs comparison costs
less, than loop thru bitmap.

This patchset raises several questions:

 Q: Think the problem you comments is already known so that I wrote comments
    about it as "it could consume lots of address space through fragmentation".
    Could you tell me about your situation and reason why it should be avoided?
                                                                     Gioh Kim

 A: Indeed, there was a commit 36437638 which adds explicit comment about
    fragmentation.  But fragmentation which is described in this comment caused
    by mixing of long-lived and short-lived objects, when a whole block is pinned
    in memory because some page slots are still in use.  But here I am talking
    about blocks which are free, nobody uses them, and allocator keeps them alive
    forever, continuously allocating new blocks.

 Q: I think that if you put newly allocated block to the tail of a free
    list, below example would results in enormous performance degradation.

    new block: 1MB (256 pages)

    while (iters--) {
      vm_map_ram(3 or something else not dividable for 256) * 85
      vm_unmap_ram(3) * 85
    }

    On every iteration, it needs newly allocated block and it is put to the
    tail of a free list so finding it consumes large amount of time.
                                                                    Joonsoo Kim

 A: Second patch in current patchset gets rid of extra search in a free list,
    so new block will be immediately occupied..

    Also, the scenario above is impossible, cause vm_map_ram allocates virtual
    range in orders, i.e. 2^n.  I.e. passing 3 to vm_map_ram you will allocate
    4 slots in a block and 256 slots (capacity of a block) of course dividable
    on 4, so block will be completely occupied.

    But there is a worst case which we can achieve: each free block has a hole
    equal to order size.

    The maximum size of allocation is 64 pages for 64-bit system
    (if you try to map more, original alloc_vmap_area will be called).

    So the maximum order is 6.  That means that worst case, before allocator
    makes a decision to allocate a new block, is to iterate 7 blocks:

    HEAD
    1st block - has 1  page slot  free (order 0)
    2nd block - has 2  page slots free (order 1)
    3rd block - has 4  page slots free (order 2)
    4th block - has 8  page slots free (order 3)
    5th block - has 16 page slots free (order 4)
    6th block - has 32 page slots free (order 5)
    7th block - has 64 page slots free (order 6)
    TAIL

    So the worst scenario on 64-bit system is that each CPU queue can have 7
    blocks in a free list.

    This can happen only and only if you allocate blocks increasing the order.
    (as I did in the function written in the comment of the first patch)
    This is weird and rare case, but still it is possible.  Afterwards you will
    get 7 blocks in a list.

    All further requests should be placed in a newly allocated block or some
    free slots should be found in a free list.
    Seems it does not look dramatically awful.

This patch (of 3):

If suitable block can't be found, new block is allocated and put into a
head of a free list, so on next iteration this new block will be found
first.

That's bad, because old blocks in a free list will not get a chance to be
fully used, thus fragmentation will grow.

Let's consider this simple example:

 #1 We have one block in a free list which is partially used, and where only
    one page is free:

    HEAD |xxxxxxxxx-| TAIL
                   ^
                   free space for 1 page, order 0

 #2 New allocation request of order 1 (2 pages) comes, new block is allocated
    since we do not have free space to complete this request. New block is put
    into a head of a free list:

    HEAD |----------|xxxxxxxxx-| TAIL

 #3 Two pages were occupied in a new found block:

    HEAD |xx--------|xxxxxxxxx-| TAIL
          ^
          two pages mapped here

 #4 New allocation request of order 0 (1 page) comes.  Block, which was created
    on #2 step, is located at the beginning of a free list, so it will be found
    first:

  HEAD |xxX-------|xxxxxxxxx-| TAIL
          ^                 ^
          page mapped here, but better to use this hole

It is obvious, that it is better to complete request of #4 step using the
old block, where free space is left, because in other case fragmentation
will be highly increased.

But fragmentation is not only the case.  The worst thing is that I can
easily create scenario, when the whole vmalloc space is exhausted by
blocks, which are not used, but already dirty and have several free pages.

Let's consider this function which execution should be pinned to one CPU:

static void exhaust_virtual_space(struct page *pages[16], int iters)
{
        /* Firstly we have to map a big chunk, e.g. 16 pages.
         * Then we have to occupy the remaining space with smaller
         * chunks, i.e. 8 pages. At the end small hole should remain.
         * So at the end of our allocation sequence block looks like
         * this:
         *                XX  big chunk
         * |XXxxxxxxx-|    x  small chunk
         *                 -  hole, which is enough for a small chunk,
         *                    but is not enough for a big chunk
         */
        while (iters--) {
                int i;
                void *vaddr;

                /* Map/unmap big chunk */
                vaddr = vm_map_ram(pages, 16, -1, PAGE_KERNEL);
                vm_unmap_ram(vaddr, 16);

                /* Map/unmap small chunks.
                 *
                 * -1 for hole, which should be left at the end of each block
                 * to keep it partially used, with some free space available */
                for (i = 0; i < (VMAP_BBMAP_BITS - 16) / 8 - 1; i++) {
                        vaddr = vm_map_ram(pages, 8, -1, PAGE_KERNEL);
                        vm_unmap_ram(vaddr, 8);
                }
        }
}

On every iteration new block (1MB of vm area in my case) will be
allocated and then will be occupied, without attempt to resolve small
allocation request using previously allocated blocks in a free list.

In case of random allocation (size should be randomly taken from the
range [1..64] in 64-bit case or [1..32] in 32-bit case) situation is the
same: new blocks continue to appear if maximum possible allocation size
(32 or 64) passed to the allocator, because all remaining blocks in a
free list do not have enough free space to complete this allocation
request.

In summary if new blocks are put into the head of a free list eventually
virtual space will be exhausted.

In current patch I simply put newly allocated block to the tail of a
free list, thus reduce fragmentation, giving a chance to resolve
allocation request using older blocks with possible holes left.
Signed-off-by: NRoman Pen <r.peniaev@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christoph Lameter <cl@linux.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: Rob Jones <rob.jones@codethink.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add min_size mount option to the hugetlbfs documentation.  Also, add the
missing pagesize option and mention that size can be specified as bytes or
a percentage of huge page pool.
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make 'min_size=<value>' be an option when mounting a hugetlbfs.  This
option takes the same value as the 'size' option.  min_size can be
specified without specifying size.  If both are specified, min_size must
be less that or equal to size else the mount will fail.  If min_size is
specified, then at mount time an attempt is made to reserve min_size
pages.  If the reservation fails, the mount fails.  At umount time, the
reserved pages are released.
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The same routines that perform subpool maximum size accounting
hugepage_subpool_get/put_pages() are modified to also perform minimum size
accounting.  When a delta value is passed to these routines, calculate how
global reservations must be adjusted to maintain the subpool minimum size.
 The routines now return this global reserve count adjustment.  This
global reserve count adjustment is then passed to the global accounting
routine hugetlb_acct_memory().
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

hugetlbfs allocates huge pages from the global pool as needed.  Even if
the global pool contains a sufficient number pages for the filesystem size
at mount time, those global pages could be grabbed for some other use.  As
a result, filesystem huge page allocations may fail due to lack of pages.

Applications such as a database want to use huge pages for performance
reasons.  hugetlbfs filesystem semantics with ownership and modes work
well to manage access to a pool of huge pages.  However, the application
would like some reasonable assurance that allocations will not fail due to
a lack of huge pages.  At application startup time, the application would
like to configure itself to use a specific number of huge pages.  Before
starting, the application can check to make sure that enough huge pages
exist in the system global pools.  However, there are no guarantees that
those pages will be available when needed by the application.  What the
application wants is exclusive use of a subset of huge pages.

Add a new hugetlbfs mount option 'min_size=<value>' to indicate that the
specified number of pages will be available for use by the filesystem.  At
mount time, this number of huge pages will be reserved for exclusive use
of the filesystem.  If there is not a sufficient number of free pages, the
mount will fail.  As pages are allocated to and freeed from the
filesystem, the number of reserved pages is adjusted so that the specified
minimum is maintained.

This patch (of 4):

Add a field to the subpool structure to indicate the minimimum number of
huge pages to always be used by this subpool.  This minimum count includes
allocated pages as well as reserved pages.  If the minimum number of pages
for the subpool have not been allocated, pages are reserved up to this
minimum.  An additional field (rsv_hpages) is used to track the number of
pages reserved to meet this minimum size.  The hstate pointer in the
subpool is convenient to have when reserving and unreserving the pages.
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When the compaction is activated via /proc/sys/vm/compact_memory it would
better scan the whole zone.  And some platforms, for instance ARM, have
the start_pfn of a zone at zero.  Therefore the first try to compact via
/proc doesn't work.  It needs to reset the compaction scanner position
first.
Signed-off-by: NGioh Kim <gioh.kim@lge.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

memcg currently uses hardcoded GFP_TRANSHUGE gfp flags for all THP
charges.  THP allocations, however, might be using different flags
depending on /sys/kernel/mm/transparent_hugepage/{,khugepaged/}defrag and
the current allocation context.

The primary difference is that defrag configured to "madvise" value will
clear __GFP_WAIT flag from the core gfp mask to make the allocation
lighter for all mappings which are not backed by VM_HUGEPAGE vmas.  If
memcg charge path ignores this fact we will get light allocation but the a
potential memcg reclaim would kill the whole point of the configuration.

Fix the mismatch by providing the same gfp mask used for the allocation to
the charge functions.  This is quite easy for all paths except for
hugepaged kernel thread with !CONFIG_NUMA which is doing a pre-allocation
long before the allocated page is used in collapse_huge_page via
khugepaged_alloc_page.  To prevent from cluttering the whole code path
from khugepaged_do_scan we simply return the current flags as per
khugepaged_defrag() value which might have changed since the
preallocation.  If somebody changed the value of the knob we would charge
differently but this shouldn't happen often and it is definitely not
critical because it would only lead to a reduced success rate of one-off
THP promotion.

[akpm@linux-foundation.org: fix weird code layout while we're there]
[rientjes@google.com: clean up around alloc_hugepage_gfpmask()]
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"deactivate_page" was created for file invalidation so it has too
specific logic for file-backed pages.  So, let's change the name of the
function and date to a file-specific one and yield the generic name.
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Wang, Yalin <Yalin.Wang@sonymobile.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/vm/unevictable-lru.txt: document interaction between compaction and the unevictable LRU

The memory compaction code uses the migration code to do most of the
work in compaction.  However, the compaction code interacts with the
unevictable LRU differently than migration code and this difference
should be noted in the documentation.

[akpm@linux-foundation.org: identify /proc/sys/vm/compact_unevictable directly]
Signed-off-by: NEric B Munson <emunson@akamai.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, pages which are marked as unevictable are protected from
compaction, but not from other types of migration.  The POSIX real time
extension explicitly states that mlock() will prevent a major page
fault, but the spirit of this is that mlock() should give a process the
ability to control sources of latency, including minor page faults.
However, the mlock manpage only explicitly says that a locked page will
not be written to swap and this can cause some confusion.  The
compaction code today does not give a developer who wants to avoid swap
but wants to have large contiguous areas available any method to achieve
this state.  This patch introduces a sysctl for controlling compaction
behavior with respect to the unevictable lru.  Users who demand no page
faults after a page is present can set compact_unevictable_allowed to 0
and users who need the large contiguous areas can enable compaction on
locked memory by leaving the default value of 1.

To illustrate this problem I wrote a quick test program that mmaps a
large number of 1MB files filled with random data.  These maps are
created locked and read only.  Then every other mmap is unmapped and I
attempt to allocate huge pages to the static huge page pool.  When the
compact_unevictable_allowed sysctl is 0, I cannot allocate hugepages
after fragmenting memory.  When the value is set to 1, allocations
succeed.
Signed-off-by: NEric B Munson <emunson@akamai.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the page flag sanitization patchset, an invalid usage of
ClearPageReclaim() is detected in set_page_dirty().  This can be called
from __unmap_hugepage_range(), so let's check PageReclaim() before trying
to clear it to avoid the misuse.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the page flag sanitization patchset, an invalid usage of
ClearPageSwapCache() is detected in migration_page_copy().
migrate_page_copy() is shared by both normal and hugepage (both thp and
hugetlb) code path, so let's check PageSwapCache() and clear it if it's
set to avoid misuse of the invalid clear operation.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

THP uses tail page refcounting to be able to split huge pages at any time.
 Tail page refcounting is not needed for other users of compound pages and
it's harmful because of overhead.

We try to exclude non-THP pages from tail page refcounting using
__compound_tail_refcounted() check.  It excludes most common non-THP
compound pages: SL*B and hugetlb, but it doesn't catch rest of __GFP_COMP
users -- drivers.

And it's not only about overhead.

Drivers might want to use compound pages to get refcounting semantics
suitable for mapping high-order pages to userspace.  But tail page
refcounting breaks it.

Tail page refcounting uses ->_mapcount in tail pages to store GUP pins on
them.  It means GUP pins would affect page_mapcount() for tail pages.
It's not a problem for THP, because it never maps tail pages.  But unlike
THP, drivers map parts of compound pages with PTEs and it makes
page_mapcount() be called for tail pages.

In particular, GUP pins would shift PSS up and affect /proc/kpagecount for
such pages.  But, I'm not aware about anything which can lead to crash or
other serious misbehaviour.

Since currently all THP pages are anonymous and all drivers pages are not,
we can fix the __compound_tail_refcounted() check by requiring PageAnon()
to enable tail page refcounting.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently we take a naive approach to page flags on compound pages - we
set the flag on the page without consideration if the flag makes sense
for tail page or for compound page in general.  This patchset try to
sort this out by defining per-flag policy on what need to be done if
page-flag helper operate on compound page.

The last patch in the patchset also sanitizes usege of page->mapping for
tail pages.  We don't define the meaning of page->mapping for tail
pages.  Currently it's always NULL, which can be inconsistent with head
page and potentially lead to problems.

For now I caught one case of illegal usage of page flags or ->mapping:
sound subsystem allocates pages with __GFP_COMP and maps them with PTEs.
It leads to setting dirty bit on tail pages and access to tail_page's
->mapping.  I don't see any bad behaviour caused by this, but worth
fixing anyway.

This patchset makes more sense if you take my THP refcounting into
account: we will see more compound pages mapped with PTEs and we need to
define behaviour of flags on compound pages to avoid bugs.

This patch (of 16):

We have page-flags helper function declarations/definitions spread over
several header files.  Let's consolidate them in <linux/page-flags.h>.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This cleanup patch moves all strings passed to action_result() into a
singl= e array action_page_type so that a reader can easily find which
kind of actio= n results are possible.  And this patch also fixes the
odd lines to be printed out, like "unknown page state page" or "free
buddy, 2nd try page".

[akpm@linux-foundation.org: rename messages, per David]
[akpm@linux-foundation.org: s/DIRTY_UNEVICTABLE_LRU/CLEAN_UNEVICTABLE_LRU', per Andi]
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Xie XiuQi" <xiexiuqi@huawei.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Low and high watermarks, as they defined in the TODO to the mem_cgroup
struct, have already been implemented by Johannes, so remove the stale
comment.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mem_cgroup_lookup() is a wrapper around mem_cgroup_from_id(), which
checks that id != 0 before issuing the function call.  Today, there is
no point in this additional check apart from optimization, because there
is no css with id <= 0, so that css_from_id, called by
mem_cgroup_from_id, will return NULL for any id <= 0.

Since mem_cgroup_from_id is only called from mem_cgroup_lookup, let us
zap mem_cgroup_lookup, substituting calls to it with mem_cgroup_from_id
and moving the check if id > 0 to css_from_id.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All callers of zone_movable_is_highmem are under #ifdef CONFIG_HIGHMEM,
so the else branch return 0 is not needed.
Signed-off-by: NZhang Zhen <zhenzhang.zhang@huawei.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Alter 'taks' -> 'task'
Signed-off-by: NYaowei Bai <bywxiaobai@163.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

vfs_readdir() was replaced by iterate_dir() in commit 5c0ba4e0
("[readdir] introduce iterate_dir() and dir_context").
Signed-off-by: NZhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull networking updates from David Miller:

 1) Add BQL support to via-rhine, from Tino Reichardt.

 2) Integrate SWITCHDEV layer support into the DSA layer, so DSA drivers
    can support hw switch offloading.  From Floria Fainelli.

 3) Allow 'ip address' commands to initiate multicast group join/leave,
    from Madhu Challa.

 4) Many ipv4 FIB lookup optimizations from Alexander Duyck.

 5) Support EBPF in cls_bpf classifier and act_bpf action, from Daniel
    Borkmann.

 6) Remove the ugly compat support in ARP for ugly layers like ax25,
    rose, etc.  And use this to clean up the neigh layer, then use it to
    implement MPLS support.  All from Eric Biederman.

 7) Support L3 forwarding offloading in switches, from Scott Feldman.

 8) Collapse the LOCAL and MAIN ipv4 FIB tables when possible, to speed
    up route lookups even further.  From Alexander Duyck.

 9) Many improvements and bug fixes to the rhashtable implementation,
    from Herbert Xu and Thomas Graf.  In particular, in the case where
    an rhashtable user bulk adds a large number of items into an empty
    table, we expand the table much more sanely.

10) Don't make the tcp_metrics hash table per-namespace, from Eric
    Biederman.

11) Extend EBPF to access SKB fields, from Alexei Starovoitov.

12) Split out new connection request sockets so that they can be
    established in the main hash table.  Much less false sharing since
    hash lookups go direct to the request sockets instead of having to
    go first to the listener then to the request socks hashed
    underneath.  From Eric Dumazet.

13) Add async I/O support for crytpo AF_ALG sockets, from Tadeusz Struk.

14) Support stable privacy address generation for RFC7217 in IPV6.  From
    Hannes Frederic Sowa.

15) Hash network namespace into IP frag IDs, also from Hannes Frederic
    Sowa.

16) Convert PTP get/set methods to use 64-bit time, from Richard
    Cochran.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1816 commits)
  fm10k: Bump driver version to 0.15.2
  fm10k: corrected VF multicast update
  fm10k: mbx_update_max_size does not drop all oversized messages
  fm10k: reset head instead of calling update_max_size
  fm10k: renamed mbx_tx_dropped to mbx_tx_oversized
  fm10k: update xcast mode before synchronizing multicast addresses
  fm10k: start service timer on probe
  fm10k: fix function header comment
  fm10k: comment next_vf_mbx flow
  fm10k: don't handle mailbox events in iov_event path and always process mailbox
  fm10k: use separate workqueue for fm10k driver
  fm10k: Set PF queues to unlimited bandwidth during virtualization
  fm10k: expose tx_timeout_count as an ethtool stat
  fm10k: only increment tx_timeout_count in Tx hang path
  fm10k: remove extraneous "Reset interface" message
  fm10k: separate PF only stats so that VF does not display them
  fm10k: use hw->mac.max_queues for stats
  fm10k: only show actual queues, not the maximum in hardware
  fm10k: allow creation of VLAN on default vid
  fm10k: fix unused warnings
  ...

Pull ARM updates from Russell King:
 "Included in this update are both some long term fixes and some new
  features.

  Fixes:

   - An integer overflow in the calculation of ELF_ET_DYN_BASE.

   - Avoiding OOMs for high-order IOMMU allocations

   - SMP requires the data cache to be enabled for synchronisation
     primitives to work, so prevent the CPU_DCACHE_DISABLE option being
     visible on SMP builds.

   - A bug going back 10+ years in the noMMU ARM94* CPU support code,
     where it corrupts registers.  Found by folk getting Linux running
     on their cameras.

   - Versatile Express needs an errata workaround enabled for CPU
     hot-unplug to work.

  Features:

   - Clean up module linker by handling out of range relocations
     separately from relocation cases we don't handle.

   - Fix a long term bug in the pci_mmap_page_range() code, which we
     hope won't impact userspace (we hope there's no users of the
     existing broken interface.)

   - Don't map DMA coherent allocations when we don't have a MMU.

   - Drop experimental status for SMP_ON_UP.

   - Warn when DT doesn't specify ePAPR mandatory cache properties.

   - Add documentation concerning how we find the start of physical
     memory for AUTO_ZRELADDR kernels, detailing why we have chosen the
     mask and the implications of changing it.

   - Updates from Ard Biesheuvel to address some issues with large
     kernels (such as allyesconfig) failing to link.

   - Allow hibernation to work on modern (ARMv7) CPUs - this appears to
     have never worked in the past on these CPUs.

   - Enable IRQ_SHOW_LEVEL, which changes the /proc/interrupts output
     format (hopefully without userspace breaking...  let's hope that if
     it causes someone a problem, they tell us.)

   - Fix tegra-ahb DT offsets.

   - Rework ARM errata 643719 code (and ARMv7 flush_cache_louis()/
     flush_dcache_all()) code to be more efficient, and enable this
     errata workaround by default for ARMv7+SMP CPUs.  This complements
     the Versatile Express fix above.

   - Rework ARMv7 context code for errata 430973, so that only Cortex A8
     CPUs are impacted by the branch target buffer flush when this
     errata is enabled.  Also update the help text to indicate that all
     r1p* A8 CPUs are impacted.

   - Switch ARM to the generic show_mem() implementation, it conveys all
     the information which we were already reporting.

   - Prevent slow timer sources being used for udelay() - timers running
     at less than 1MHz are not useful for this, and can cause udelay()
     to return immediately, without any wait.  Using such a slow timer
     is silly.

   - VDSO support for 32-bit ARM, mainly for gettimeofday() using the
     ARM architected timer.

   - Perf support for Scorpion performance monitoring units"

vdso semantic conflict fixed up as per linux-next.

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (52 commits)
  ARM: update errata 430973 documentation to cover Cortex A8 r1p*
  ARM: ensure delay timer has sufficient accuracy for delays
  ARM: switch to use the generic show_mem() implementation
  ARM: proc-v7: avoid errata 430973 workaround for non-Cortex A8 CPUs
  ARM: enable ARM errata 643719 workaround by default
  ARM: cache-v7: optimise test for Cortex A9 r0pX devices
  ARM: cache-v7: optimise branches in v7_flush_cache_louis
  ARM: cache-v7: consolidate initialisation of cache level index
  ARM: cache-v7: shift CLIDR to extract appropriate field before masking
  ARM: cache-v7: use movw/movt instructions
  ARM: allow 16-bit instructions in ALT_UP()
  ARM: proc-arm94*.S: fix setup function
  ARM: vexpress: fix CPU hotplug with CT9x4 tile.
  ARM: 8276/1: Make CPU_DCACHE_DISABLE depend on !SMP
  ARM: 8335/1: Documentation: DT bindings: Tegra AHB: document the legacy base address
  ARM: 8334/1: amba: tegra-ahb: detect and correct bogus base address
  ARM: 8333/1: amba: tegra-ahb: fix register offsets in the macros
  ARM: 8339/1: Enable CONFIG_GENERIC_IRQ_SHOW_LEVEL
  ARM: 8338/1: kexec: Relax SMP validation to improve DT compatibility
  ARM: 8337/1: mm: Do not invoke OOM for higher order IOMMU DMA allocations
  ...

Pull s390 updates from Martin Schwidefsky:
 "The major change in this merge is the removal of the support for
  31-bit kernels.  Naturally 31-bit user space will continue to work via
  the compat layer.

  And then some cleanup, some improvements and bug fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (23 commits)
  s390/smp: wait until secondaries are active & online
  s390/hibernate: fix save and restore of kernel text section
  s390/cacheinfo: add missing facility check
  s390/syscalls: simplify syscall_get_arch()
  s390/irq: enforce correct irqclass_sub_desc array size
  s390: remove "64" suffix from mem64.S and swsusp_asm64.S
  s390/ipl: cleanup macro usage
  s390/ipl: cleanup shutdown_action attributes
  s390/ipl: cleanup bin attr usage
  s390/uprobes: fix address space annotation
  s390: add missing arch_release_task_struct() declaration
  s390: make couple of functions and variables static
  s390/maccess: improve s390_kernel_write()
  s390/maccess: remove potentially broken probe_kernel_write()
  s390/watchdog: support for KVM hypervisors and delete pr_info messages
  s390/watchdog: enable KEEPALIVE for /dev/watchdog
  s390/dasd: remove setting of scheduler from driver
  s390/traps: panic() instead of die() on translation exception
  s390: remove test_facility(2) (== z/Architecture mode active) checks
  s390/cmpxchg: simplify cmpxchg_double
  ...

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2015-04-14

This series contains updates to fm10k only.

Fixed transmit statistics which was actually using values from the
receive ring, instead of the transmit ring.  Fixed up spelling mistakes
in code comments and resolved unused argument warnings.  Added support
for netconsole.  Fixed up statistic reporting so that we are only
reporting from actual queues as well as display PF only stats for
just the PF and not the VF.  Also fixed an issue that when returning
virtualization queues from the VF back to the PF, we were retaining
the VF rate limiter.

Fixed up the driver to use a separate workqueue, which helps reduce
and stabilize latency between scheduling the work in our interrupt and
actually performing the work.

Fixed a bug where the VF tried to set a multicast address before
requesting the required xcast mode.

Fix VF multicast update since VFs were being improperly added to the
switch's mutlicast group.  The error stems from the fact that incorrect
arguments were passed to the update_mc_addr().

Thanks to Alex Duyck for the extensive review.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull input subsystem updates from Dmitry Torokhov:
 "You will get the following new drivers:

   - Qualcomm PM8941 power key drver
   - ChipOne icn8318 touchscreen controller driver
   - Broadcom iProc touchscreen and keypad drivers
   - Semtech SX8654 I2C touchscreen controller driver

  ALPS driver now supports newer SS4 devices; Elantech got a fix that
  should make it work on some ASUS laptops; and a slew of other
  enhancements and random fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (51 commits)
  Input: alps - non interleaved V2 dualpoint has separate stick button bits
  Input: alps - fix touchpad buttons getting stuck when used with trackpoint
  Input: atkbd - document "no new force-release quirks" policy
  Input: ALPS - make alps_get_pkt_id_ss4_v2() and others static
  Input: ALPS - V7 devices can report 5-finger taps
  Input: ALPS - add support for SS4 touchpad devices
  Input: ALPS - refactor alps_set_abs_params_mt()
  Input: elantech - fix absolute mode setting on some ASUS laptops
  Input: atmel_mxt_ts - split out touchpad initialisation logic
  Input: atmel_mxt_ts - implement support for T100 touch object
  Input: cros_ec_keyb - fix clearing keyboard state on wakeup
  Input: gscps2 - drop pci_ids dependency
  Input: synaptics - allocate 3 slots to keep stability in image sensors
  Input: Revert "Revert "synaptics - use dmax in input_mt_assign_slots""
  Input: MT - make slot assignment work for overcovered solutions
  mfd: tc3589x: enforce device-tree only mode
  Input: tc3589x - localize platform data
  Input: tsc2007 - Convert msecs to jiffies only once
  Input: edt-ft5x06 - remove EV_SYN event report
  Input: edt-ft5x06 - allow to setting the maximum axes value through the DT
  ...

Pull i2c updates from Wolfram Sang:
 "Most notable:

   - introducing the i2c_quirk infrastructure.  Now, flaws of I2C
     controllers can be described and the core will check if the flaws
     collide with the messages to be sent

   - wait_for_completion return type cleanup series

   - new drivers for Digicolor, Netlogic XLP, Ingenic JZ4780

   - updates to the I2C slave framework which include API changes.  Its
     only user was updated, too.  Documentation was finally added

   - changed dynamic bus numbering for the DT case.  This could change
     bus numbers for users.  However, it fixes a collision where dynamic
     and static busses request the same id.

   - driver bugfixes, cleanups"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
  i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller
  of: Add vendor prefix 'netlogic'
  i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
  i2c: davinci: use bus recovery infrastructure
  i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
  i2c: i2c-mux-gpio: remove error messages for probe deferrals
  i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780
  i2c: dln2: set the device tree node of the adapter
  i2c: davinci: fixup wait_for_completion_timeout handling
  i2c: mpc: Fix ISR return value
  i2c: slave-eeprom: add more info when to increase the pointer
  i2c: slave: add documentation for i2c-slave-eeprom
  Documentation: i2c: describe the new slave mode
  i2c: slave: rework the slave API
  i2c: add support for the Digicolor I2C controller
  i2c: busses with dynamic ids should start after fixed ids for DT
  of: base: add function to get highest id of an alias stem
  i2c: designware: Suppress error message if platform_get_irq() < 0
  i2c: mpc: assign the correct prescaler from SVR
  i2c: img-scb: fixup of wait_for_completion_timeout return handling
  ...

Pull VFIO updates from Alex Williamson:

 - VFIO platform bus driver support (Baptiste Reynal, Antonios Motakis,
   testing and review by Eric Auger)

 - Split VFIO irqfd support to separate module (Alex Williamson)

 - vfio-pci VGA arbiter client (Alex Williamson)

 - New vfio-pci.ids= module option (Alex Williamson)

 - vfio-pci D3 power state support for idle devices (Alex Williamson)

* tag 'vfio-v4.1-rc1' of git://github.com/awilliam/linux-vfio: (30 commits)
  vfio-pci: Fix use after free
  vfio-pci: Move idle devices to D3hot power state
  vfio-pci: Remove warning if try-reset fails
  vfio-pci: Allow PCI IDs to be specified as module options
  vfio-pci: Add VGA arbiter client
  vfio-pci: Add module option to disable VGA region access
  vgaarb: Stub vga_set_legacy_decoding()
  vfio: Split virqfd into a separate module for vfio bus drivers
  vfio: virqfd_lock can be static
  vfio: put off the allocation of "minor" in vfio_create_group
  vfio/platform: implement IRQ masking/unmasking via an eventfd
  vfio: initialize the virqfd workqueue in VFIO generic code
  vfio: move eventfd support code for VFIO_PCI to a separate file
  vfio: pass an opaque pointer on virqfd initialization
  vfio: add local lock for virqfd instead of depending on VFIO PCI
  vfio: virqfd: rename vfio_pci_virqfd_init and vfio_pci_virqfd_exit
  vfio: add a vfio_ prefix to virqfd_enable and virqfd_disable and export
  vfio/platform: support for level sensitive interrupts
  vfio/platform: trigger an interrupt via eventfd
  vfio/platform: initial interrupts support code
  ...

Pull pincontrol updates from Linus Walleij:
 "This is the bulk of pin control changes for the v4.1 development
  cycle.  Nothing really exciting this time: we basically added a few
  new drivers and subdrivers and stabilized them in linux-next.  Some
  cleanups too.  With sunrisepoint Intel has a real fine fully featured
  pin control driver for contemporary hardware, and the AMD driver is
  also for large deployments.  Most of the others are ARM devices.

  New drivers:
    - Intel Sunrisepoint
    - AMD KERNCZ GPIO
    - Broadcom Cygnus IOMUX

  New subdrivers:
    - Marvell MVEBU Armada 39x SoCs
    - Samsung Exynos 5433
    - nVidia Tegra 210
    - Mediatek MT8135
    - Mediatek MT8173
    - AMLogic Meson8b
    - Qualcomm PM8916

  On top of this cleanups and development history for the above drivers
  as issues were fixed after merging"

* tag 'pinctrl-v4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (71 commits)
  pinctrl: sirf: move sgpio lock into state container
  pinctrl: Add support for PM8916 GPIO's and MPP's
  pinctrl: bcm2835: Fix support for threaded level triggered IRQs
  sh-pfc: r8a7790: add EtherAVB pin groups
  pinctrl: Document "function" + "pins" pinmux binding
  pinctrl: intel: Add Intel Sunrisepoint pin controller and GPIO support
  pinctrl: fsl: imx: Check for 0 config register
  pinctrl: Add support for Meson8b
  documentation: Extend pinctrl docs for Meson8b
  pinctrl: Cleanup Meson8 driver
  Fix inconsistent spinlock of AMD GPIO driver which can be recognized by static analysis tool smatch. Declare constant Variables with Sparse's suggestion.
  pinctrl: at91: convert __raw to endian agnostic IO
  pinctrl: constify of_device_id array
  pinctrl: pinconf-generic: add dt node names to error messages
  pinctrl: pinconf-generic: scan also referenced phandle node
  pinctrl: mvebu: add suspend/resume support to Armada XP pinctrl driver
  pinctrl: st: Display pin's function when printing pinctrl debug information
  pinctrl: st: Show correct pin direction also in GPIO mode
  pinctrl: st: Supply a GPIO get_direction() call-back
  pinctrl: st: Move st_get_pio_control() further up the source file
  ...

Pull backlight updates from Lee Jones:
 "Changes to existing drivers:

   - Use of_get_child_by_name() instead of refcount; 88pm860x_bl

   - Terminate array with NULL element; da9052_bl"

* tag 'backlight-for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: da9052_bl: Terminate da9052_wled_ids array with empty element
  backlight: 88pm860x_bl: Use of_get_child_by_name() instead of refcount hack

Pull MFD updates from Lee Jones:
 "Changes to existing drivers:

   - Rename child driver [axp288_battery => axp288_fuel_gauge]; axp20x
   - Rename child driver [max77693-flash => max77693-led]; max77693
   - Error handling fixes; intel_soc_pmic
   - GPIO tweaking; intel_soc_pmic
   - Remove non-DT code; vexpress-sysreg, tc3589x
   - Remove unused/legacy code; ti_am335x_tscadc, rts5249, rtsx_gops, rtsx_pcr,
                                rtc-s5m, sec-core, max77693, menelaus,
                                wm5102-tables
   - Trivial fixups; rtsx_pci, da9150-core, sec-core, max7769, max77693,
                     mc13xxx-core, dln2, hi6421-pmic-core, rk808, twl4030-power,
                     lpc_ich, menelaus, twl6040
   - Update register/address values; rts5227, rts5249
   - DT and/or binding document fixups; arizona, da9150, mt6397, axp20x,
                                        qcom-rpm, qcom-spmi-pmic
   - Couple of trivial core Kconfig fixups
   - Remove use of seq_printf return value; ab8500-debugfs
   - Remove __exit markups; menelaus, tps65010
   - Fix platform-device name collisions; mfd-core

  New drivers/supported devices:

   - Add support for wm8280/wm8281 into arizona
   - Add support for COMe-cBL6 into kempld-core
   - Add support for rts524a and rts525a into rts5249
   - Add support for ipq8064 into qcom_rpm
   - Add support for extcon into axp20x
   - New MediaTek MT6397 PMIC driver
   - New Maxim MAX77843 PMIC dirver
   - New Intel Quark X1000 I2C-GPIO driver
   - New Skyworks SKY81452 driver"

* tag 'mfd-for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (76 commits)
  mfd: sec: Fix RTC alarm interrupt number on S2MPS11
  mfd: wm5102: Remove registers for output 3R from readable list
  mfd: tps65010: Remove incorrect __exit markups
  mfd: devicetree: bindings: Add Qualcomm RPM regulator subnodes
  mfd: axp20x: Add support for extcon cell
  mfd: lpc_ich: Sort IDs
  mfd: twl6040: Remove wrong and unneeded "platform:twl6040" modalias
  mfd: qcom-spmi-pmic: Add specific compatible strings for Qualcomm's SPMI PMIC's
  mfd: axp20x: Fix duplicate const for model names
  mfd: menelaus: Use macro for magic number
  mfd: menelaus: Drop support for SW controller VCORE
  mfd: menelaus: Delete omap_has_menelaus
  mfd: arizona: Correct type of gpio_defaults
  mfd: lpc_ich: Sort IDs
  mfd: Fix a typo in Kconfig
  mfd: qcom_rpm: Add support for IPQ8064
  mfd: devicetree: qcom_rpm: Document IPQ8064 resources
  mfd: core: Fix platform-device name collisions
  mfd: intel_quark_i2c_gpio: Don't crash if !DMI
  dt-bindings: Add vendor-prefix for X-Powers
  ...

Merge first patchbomb from Andrew Morton:

 - arch/sh updates

 - ocfs2 updates

 - kernel/watchdog feature

 - about half of mm/

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (122 commits)
  Documentation: update arch list in the 'memtest' entry
  Kconfig: memtest: update number of test patterns up to 17
  arm: add support for memtest
  arm64: add support for memtest
  memtest: use phys_addr_t for physical addresses
  mm: move memtest under mm
  mm, hugetlb: abort __get_user_pages if current has been oom killed
  mm, mempool: do not allow atomic resizing
  memcg: print cgroup information when system panics due to panic_on_oom
  mm: numa: remove migrate_ratelimited
  mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
  mm: split ET_DYN ASLR from mmap ASLR
  s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
  mm: expose arch_mmap_rnd when available
  s390: standardize mmap_rnd() usage
  powerpc: standardize mmap_rnd() usage
  mips: extract logic for mmap_rnd()
  arm64: standardize mmap_rnd() usage
  x86: standardize mmap_rnd() usage
  arm: factor out mmap ASLR into mmap_rnd
  ...

Since arm64/arm support memtest command line option update the "memtest"
entry.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Additional test patterns for memtest were introduced since commit
63823126 ("x86: memtest: add additional (regular) test patterns"),
but looks like Kconfig was not updated that time.

Update Kconfig entry with the actual number of maximum test patterns.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for memtest command line option.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>