diff mbox series

[RFC,01/10] mm/hugetlb: Let vma_offset_start() to return start

Message ID 20221030212929.335473-2-peterx@redhat.com (mailing list archive)
State New
Headers show
Series mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare | expand

Commit Message

Peter Xu Oct. 30, 2022, 9:29 p.m. UTC 
Even though vma_offset_start() is named like that, it's not returning "the
start address of the range" but rather the offset we should use to offset
the vma->vm_start address.

Make it return the real value of the start vaddr, and it also helps for all
the callers because whenever the retval is used, it'll be ultimately added
into the vma->vm_start anyway, so it's better.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 fs/hugetlbfs/inode.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

Comments

Mike Kravetz Nov. 3, 2022, 3:25 p.m. UTC | #1 
On 10/30/22 17:29, Peter Xu wrote:
> Even though vma_offset_start() is named like that, it's not returning "the
> start address of the range" but rather the offset we should use to offset
> the vma->vm_start address.
> 
> Make it return the real value of the start vaddr, and it also helps for all
> the callers because whenever the retval is used, it'll be ultimately added
> into the vma->vm_start anyway, so it's better.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  fs/hugetlbfs/inode.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)

Thanks, nice cleanup/simplification.

Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
diff mbox series

Patch

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 3ee84604e36d..ac3a69fe29c3 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -412,10 +412,12 @@  static bool hugetlb_vma_maps_page(struct vm_area_struct *vma,
  */
 static unsigned long vma_offset_start(struct vm_area_struct *vma, pgoff_t start)
 {
+	unsigned long offset = 0;
+
 	if (vma->vm_pgoff < start)
-		return (start - vma->vm_pgoff) << PAGE_SHIFT;
-	else
-		return 0;
+		offset = (start - vma->vm_pgoff) << PAGE_SHIFT;
+
+	return vma->vm_start + offset;
 }
 
 static unsigned long vma_offset_end(struct vm_area_struct *vma, pgoff_t end)
@@ -457,7 +459,7 @@  static void hugetlb_unmap_file_folio(struct hstate *h,
 		v_start = vma_offset_start(vma, start);
 		v_end = vma_offset_end(vma, end);
 
-		if (!hugetlb_vma_maps_page(vma, vma->vm_start + v_start, page))
+		if (!hugetlb_vma_maps_page(vma, v_start, page))
 			continue;
 
 		if (!hugetlb_vma_trylock_write(vma)) {
@@ -473,8 +475,8 @@  static void hugetlb_unmap_file_folio(struct hstate *h,
 			break;
 		}
 
-		unmap_hugepage_range(vma, vma->vm_start + v_start, v_end,
-				NULL, ZAP_FLAG_DROP_MARKER);
+		unmap_hugepage_range(vma, v_start, v_end, NULL,
+				     ZAP_FLAG_DROP_MARKER);
 		hugetlb_vma_unlock_write(vma);
 	}
 
@@ -507,10 +509,9 @@  static void hugetlb_unmap_file_folio(struct hstate *h,
 		 */
 		v_start = vma_offset_start(vma, start);
 		v_end = vma_offset_end(vma, end);
-		if (hugetlb_vma_maps_page(vma, vma->vm_start + v_start, page))
-			unmap_hugepage_range(vma, vma->vm_start + v_start,
-						v_end, NULL,
-						ZAP_FLAG_DROP_MARKER);
+		if (hugetlb_vma_maps_page(vma, v_start, page))
+			unmap_hugepage_range(vma, v_start, v_end, NULL,
+					     ZAP_FLAG_DROP_MARKER);
 
 		kref_put(&vma_lock->refs, hugetlb_vma_lock_release);
 		hugetlb_vma_unlock_write(vma);
@@ -540,8 +541,7 @@  hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end,
 		v_start = vma_offset_start(vma, start);
 		v_end = vma_offset_end(vma, end);
 
-		unmap_hugepage_range(vma, vma->vm_start + v_start, v_end,
-				     NULL, zap_flags);
+		unmap_hugepage_range(vma, v_start, v_end, NULL, zap_flags);
 
 		/*
 		 * Note that vma lock only exists for shared/non-private