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 <[e-mail]>
Cc: "Kirill A. Shutemov" <[e-mail]>
Cc: Andrea Arcangeli <[e-mail]>
Cc: Andres Lagar-Cavilla <[e-mail]>
Cc: Yang Shi <[e-mail]>
Cc: Ning Qu <[e-mail]>
Cc: Mel Gorman <[e-mail]>
Cc: Andres Lagar-Cavilla <[e-mail]>
Cc: Konstantin Khlebnikov <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/linux/huge_mm.h

···
 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,

mm/huge_memory.c

···
 	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;
 
 	/*

mm/mremap.c

···
 				/* 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) {