From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Wed, 20 Jul 2022 02:18:00 +0000 (+0000)
Subject: mm/ksm: use vma iterators instead of vma linked list
X-Git-Tag: howlett/maple/20220722_2~82
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=d842fcaaba39f1d8a2fa0d008e2da3186499efd1;p=users%2Fjedix%2Flinux-maple.git

mm/ksm: use vma iterators instead of vma linked list

Remove the use of the linked list for eventual removal.

Link: https://lkml.kernel.org/r/20220504011345.662299-38-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-54-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220720021727.17018-54-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/ksm.c b/mm/ksm.c
index 55f1d9634869..075123602bd0 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -981,11 +981,13 @@ 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)
@@ -2232,6 +2234,7 @@ 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))
@@ -2290,13 +2293,13 @@ next_mm:
 	}
 
 	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)
@@ -2334,6 +2337,7 @@ next_mm:
 	}
 
 	if (ksm_test_exit(mm)) {
+no_vmas:
 		ksm_scan.address = 0;
 		ksm_scan.rmap_list = &slot->rmap_list;
 	}