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 07fcf63f9b01a0aa961f101fbc4e6628debac634..d53d236f7869f35632b8e98104bb45f893cee6b1 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2842,7 +2842,7 @@ 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;