[PATCH v7 54/70] mm/ksm: Use vma iterators instead of vma linked list

[Liam Howlett]

From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>

Remove the use of the linked list for eventual removal.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
 mm/ksm.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/mm/ksm.c b/mm/ksm.c
index 063a48eeb5ee..c60c313d6052 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -974,11 +974,13 @@ static int unmerge_and_remove_all_rmap_items(void)
 						struct mm_slot, mm_list);
 	spin_unlock(&ksm_mmlist_lock);
 
-	for (mm_slot = ksm_scan.mm_slot;
-			mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
+	for (mm_slot = ksm_scan.mm_slot; mm_slot != &ksm_mm_head;
+	     mm_slot = ksm_scan.mm_slot) {
+		VMA_ITERATOR(vmi, mm_slot->mm, 0);
+
 		mm = mm_slot->mm;
 		mmap_read_lock(mm);
-		for (vma = mm->mmap; vma; vma = vma->vm_next) {
+		for_each_vma(vmi, vma) {
 			if (ksm_test_exit(mm))
 				break;
 			if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
@@ -2213,6 +2215,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
 	struct mm_slot *slot;
 	struct vm_area_struct *vma;
 	struct rmap_item *rmap_item;
+	struct vma_iterator vmi;
 	int nid;
 
 	if (list_empty(&ksm_mm_head.mm_list))
@@ -2271,13 +2274,13 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
 	}
 
 	mm = slot->mm;
+	vma_iter_init(&vmi, mm, ksm_scan.address);
+
 	mmap_read_lock(mm);
 	if (ksm_test_exit(mm))
-		vma = NULL;
-	else
-		vma = find_vma(mm, ksm_scan.address);
+		goto no_vmas;
 
-	for (; vma; vma = vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		if (!(vma->vm_flags & VM_MERGEABLE))
 			continue;
 		if (ksm_scan.address < vma->vm_start)
@@ -2315,6 +2318,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
 	}
 
 	if (ksm_test_exit(mm)) {
+no_vmas:
 		ksm_scan.address = 0;
 		ksm_scan.rmap_list = &slot->rmap_list;
 	}
-- 
2.34.1