thp: pte alloc trans splitting

pte alloc routines must wait for split_huge_page if the pmd is not present
and not null (i.e.  pmd_trans_splitting).  The additional branches are
optimized away at compile time by pmd_trans_splitting if the config option
is off.  However we must pass the vma down in order to know the anon_vma
lock to wait for.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6bef67d74adf..14ddd98b063f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1131,7 +1131,8 @@ static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
 #endif
 
-int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
+int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+                pmd_t *pmd, unsigned long address);
 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
 
 /*
@@ -1200,16 +1201,18 @@ static inline void pgtable_page_dtor(struct page *page)
         pte_unmap(pte);                                 \
 } while (0)
 
-#define pte_alloc_map(mm, pmd, address)                 \
-        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
-                NULL: pte_offset_map(pmd, address))
+#define pte_alloc_map(mm, vma, pmd, address)                            \
+        ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, vma,    \
+                                                        pmd, address))? \
+         NULL: pte_offset_map(pmd, address))
 
 #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
-        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
+        ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, NULL,   \
+                                                        pmd, address))? \
                 NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
 
 #define pte_alloc_kernel(pmd, address)                  \
-        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
+        ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
                 NULL: pte_offset_kernel(pmd, address))
 
 extern void free_area_init(unsigned long * zones_size);