mm: Optimize find_exact_vma() to use vma_lookup()

Use vma_lookup() to walk the tree to the start value requested.  If
the vma at the start does not match, then the answer is NULL and there
is no need to look at the next vma the way that find_vma() would.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index df20801b7d53a2ce180ef1ae4275ff032dc55c52..b99d59fc0ebfaf7145265e225e9da774f0cb5d1f 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2742,7 +2742,7 @@ static inline unsigned long vma_pages(struct vm_area_struct *vma)
 static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
                                unsigned long vm_start, unsigned long vm_end)
 {
-       struct vm_area_struct *vma = find_vma(mm, vm_start);
+       struct vm_area_struct *vma = vma_lookup(mm, vm_start);
 
        if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
                vma = NULL;