releases/3.1.1/thp-share-get_huge_page_tail.patch

   1 From b35a35b556f5e6b7993ad0baf20173e75c09ce8c Mon Sep 17 00:00:00 2001
   2 From: Andrea Arcangeli <aarcange@redhat.com>
   3 Date: Wed, 2 Nov 2011 13:37:36 -0700
   4 Subject: thp: share get_huge_page_tail()
   5
   6 From: Andrea Arcangeli <aarcange@redhat.com>
   7
   8 commit b35a35b556f5e6b7993ad0baf20173e75c09ce8c upstream.
   9
  10 This avoids duplicating the function in every arch gup_fast.
  11
  12 Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
  13 Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
  14 Cc: Hugh Dickins <hughd@google.com>
  15 Cc: Johannes Weiner <jweiner@redhat.com>
  16 Cc: Rik van Riel <riel@redhat.com>
  17 Cc: Mel Gorman <mgorman@suse.de>
  18 Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
  19 Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
  20 Cc: David Gibson <david@gibson.dropbear.id.au>
  21 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
  22 Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
  23 Cc: David Miller <davem@davemloft.net>
  24 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  25 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  27
  28 ---
  29  arch/powerpc/mm/hugetlbpage.c |   11 -----------
  30  arch/s390/mm/gup.c            |   11 -----------
  31  arch/sparc/mm/gup.c           |   11 -----------
  32  arch/x86/mm/gup.c             |   11 -----------
  33  include/linux/mm.h            |   11 +++++++++++
  34  5 files changed, 11 insertions(+), 44 deletions(-)
  35
  36 --- a/arch/powerpc/mm/hugetlbpage.c
  37 +++ b/arch/powerpc/mm/hugetlbpage.c
  38 @@ -385,17 +385,6 @@ follow_huge_pmd(struct mm_struct *mm, un
  39         return NULL;
  40  }
  41
  42 -static inline void get_huge_page_tail(struct page *page)
  43 -{
  44 -       /*
  45 -        * __split_huge_page_refcount() cannot run
  46 -        * from under us.
  47 -        */
  48 -       VM_BUG_ON(page_mapcount(page) < 0);
  49 -       VM_BUG_ON(atomic_read(&page->_count) != 0);
  50 -       atomic_inc(&page->_mapcount);
  51 -}
  52 -
  53  static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
  54                        unsigned long end, int write, struct page **pages, int *nr)
  55  {
  56 --- a/arch/s390/mm/gup.c
  57 +++ b/arch/s390/mm/gup.c
  58 @@ -48,17 +48,6 @@ static inline int gup_pte_range(pmd_t *p
  59         return 1;
  60  }
  61
  62 -static inline void get_huge_page_tail(struct page *page)
  63 -{
  64 -       /*
  65 -        * __split_huge_page_refcount() cannot run
  66 -        * from under us.
  67 -        */
  68 -       VM_BUG_ON(page_mapcount(page) < 0);
  69 -       VM_BUG_ON(atomic_read(&page->_count) != 0);
  70 -       atomic_inc(&page->_mapcount);
  71 -}
  72 -
  73  static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
  74                 unsigned long end, int write, struct page **pages, int *nr)
  75  {
  76 --- a/arch/sparc/mm/gup.c
  77 +++ b/arch/sparc/mm/gup.c
  78 @@ -12,17 +12,6 @@
  79  #include <linux/rwsem.h>
  80  #include <asm/pgtable.h>
  81
  82 -static inline void get_huge_page_tail(struct page *page)
  83 -{
  84 -       /*
  85 -        * __split_huge_page_refcount() cannot run
  86 -        * from under us.
  87 -        */
  88 -       VM_BUG_ON(page_mapcount(page) < 0);
  89 -       VM_BUG_ON(atomic_read(&page->_count) != 0);
  90 -       atomic_inc(&page->_mapcount);
  91 -}
  92 -
  93  /*
  94   * The performance critical leaf functions are made noinline otherwise gcc
  95   * inlines everything into a single function which results in too much
  96 --- a/arch/x86/mm/gup.c
  97 +++ b/arch/x86/mm/gup.c
  98 @@ -108,17 +108,6 @@ static inline void get_head_page_multipl
  99         SetPageReferenced(page);
 100  }
 101
 102 -static inline void get_huge_page_tail(struct page *page)
 103 -{
 104 -       /*
 105 -        * __split_huge_page_refcount() cannot run
 106 -        * from under us.
 107 -        */
 108 -       VM_BUG_ON(page_mapcount(page) < 0);
 109 -       VM_BUG_ON(atomic_read(&page->_count) != 0);
 110 -       atomic_inc(&page->_mapcount);
 111 -}
 112 -
 113  static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr,
 114                 unsigned long end, int write, struct page **pages, int *nr)
 115  {
 116 --- a/include/linux/mm.h
 117 +++ b/include/linux/mm.h
 118 @@ -376,6 +376,17 @@ static inline int page_count(struct page
 119         return atomic_read(&compound_head(page)->_count);
 120  }
 121
 122 +static inline void get_huge_page_tail(struct page *page)
 123 +{
 124 +       /*
 125 +        * __split_huge_page_refcount() cannot run
 126 +        * from under us.
 127 +        */
 128 +       VM_BUG_ON(page_mapcount(page) < 0);
 129 +       VM_BUG_ON(atomic_read(&page->_count) != 0);
 130 +       atomic_inc(&page->_mapcount);
 131 +}
 132 +
 133  extern bool __get_page_tail(struct page *page);
 134
 135  static inline void get_page(struct page *page)