From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
This simplifies the implementation and is faster than using the linked
list.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/mmap.c | 24 +++++++-----------------
1 file changed, 7 insertions(+), 17 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 4623e69e2c4d..72e66cf755d1 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -670,29 +670,19 @@ munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len,
return 0;
}
+
static unsigned long count_vma_pages_range(struct mm_struct *mm,
unsigned long addr, unsigned long end)
{
- unsigned long nr_pages = 0;
+ VMA_ITERATOR(vmi, mm, addr);
struct vm_area_struct *vma;
+ unsigned long nr_pages = 0;
- /* Find first overlapping mapping */
- vma = find_vma_intersection(mm, addr, end);
- if (!vma)
- return 0;
-
- nr_pages = (min(end, vma->vm_end) -
- max(addr, vma->vm_start)) >> PAGE_SHIFT;
-
- /* Iterate over the rest of the overlaps */
- for (vma = vma->vm_next; vma; vma = vma->vm_next) {
- unsigned long overlap_len;
-
- if (vma->vm_start > end)
- break;
+ for_each_vma_range(vmi, vma, end) {
+ unsigned long vm_start = max(addr, vma->vm_start);
+ unsigned long vm_end = min(end, vma->vm_end);
- overlap_len = min(end, vma->vm_end) - vma->vm_start;
- nr_pages += overlap_len >> PAGE_SHIFT;
+ nr_pages += (vm_end - vm_start) / PAGE_SIZE;
}
return nr_pages;
--
2.34.1
