huge mm: move_huge_pmd does not need new_vma

Remove move_huge_pmd()'s redundant new_vma arg: all it was used for was
a VM_NOHUGEPAGE check on new_vma flags, but the new_vma is cloned from
the old vma, so a trans_huge_pmd in the new_vma will be as acceptable as
it was in the old vma, alignment and size permitting.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Ning Qu <quning@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 5 insertions, 11 deletions

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index d7b9e5346fba..419fb9e03447 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -28,9 +28,7 @@ extern int zap_huge_pmd(struct mmu_gather *tlb,
 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
                         unsigned long addr, unsigned long end,
                         unsigned char *vec);
-extern bool move_huge_pmd(struct vm_area_struct *vma,
-                         struct vm_area_struct *new_vma,
-                         unsigned long old_addr,
+extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
                          unsigned long new_addr, unsigned long old_end,
                          pmd_t *old_pmd, pmd_t *new_pmd);
 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f8ac8f582fd8..66675eed67be 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1698,20 +1698,17 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
         return 1;
 }
 
-bool move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
-                  unsigned long old_addr,
+bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
                   unsigned long new_addr, unsigned long old_end,
                   pmd_t *old_pmd, pmd_t *new_pmd)
 {
         spinlock_t *old_ptl, *new_ptl;
         pmd_t pmd;
-
         struct mm_struct *mm = vma->vm_mm;
 
         if ((old_addr & ~HPAGE_PMD_MASK) ||
             (new_addr & ~HPAGE_PMD_MASK) ||
-            old_end - old_addr < HPAGE_PMD_SIZE ||
-            (new_vma->vm_flags & VM_NOHUGEPAGE))
+            old_end - old_addr < HPAGE_PMD_SIZE)
                 return false;
 
         /*
diff --git a/mm/mremap.c b/mm/mremap.c
index 3fa0a467df66..7d98fe1adc12 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -198,9 +198,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
                                 /* See comment in move_ptes() */
                                 if (need_rmap_locks)
                                         anon_vma_lock_write(vma->anon_vma);
-                                moved = move_huge_pmd(vma, new_vma, old_addr,
-                                                    new_addr, old_end,
-                                                    old_pmd, new_pmd);
+                                moved = move_huge_pmd(vma, old_addr, new_addr,
+                                                    old_end, old_pmd, new_pmd);
                                 if (need_rmap_locks)
                                         anon_vma_unlock_write(vma->anon_vma);
                                 if (moved) {