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>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 4c2341bcaf03edc49d86b7ce27e7d889fc44d86d..110b1dcfb0367e2303dd917ab18d200bce7d0513 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2856,7 +2856,7 @@ 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;