mm: memory_hotplug: unify Huge/LRU/non-LRU movable folio isolation

Use the isolate_folio_to_list() to unify hugetlb/LRU/non-LRU folio
isolation, which cleanup code a bit and save a few calls to
compound_head().

[wangkefeng.wang@huawei.com: various fixes]
  Link: https://lkml.kernel.org/r/20240829150500.2599549-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240827114728.3212578-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory_hotplug.c

@@ -1772,15 +1772,14 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
 
 static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 {
+	struct folio *folio;
 	unsigned long pfn;
-	struct page *page;
 	LIST_HEAD(source);
 	static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL,
 				      DEFAULT_RATELIMIT_BURST);
 
 	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
-		struct folio *folio;
-		bool isolated;
+		struct page *page;
 
 		if (!pfn_valid(pfn))
 			continue;
@@ -1811,34 +1810,21 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 			continue;
 		}
 
-		if (folio_test_hugetlb(folio)) {
-			isolate_hugetlb(folio, &source);
+		if (!folio_try_get(folio))
 			continue;
-		}
 
-		if (!get_page_unless_zero(page))
-			continue;
-		/*
-		 * We can skip free pages. And we can deal with pages on
-		 * LRU and non-lru movable pages.
-		 */
-		if (PageLRU(page))
-			isolated = isolate_lru_page(page);
-		else
-			isolated = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
-		if (isolated) {
-			list_add_tail(&page->lru, &source);
-			if (!__PageMovable(page))
-				inc_node_page_state(page, NR_ISOLATED_ANON +
-						    page_is_file_lru(page));
+		if (unlikely(page_folio(page) != folio))
+			goto put_folio;
 
-		} else {
+		if (!isolate_folio_to_list(folio, &source)) {
 			if (__ratelimit(&migrate_rs)) {
-				pr_warn("failed to isolate pfn %lx\n", pfn);
+				pr_warn("failed to isolate pfn %lx\n",
+					page_to_pfn(page));
 				dump_page(page, "isolation failed");
 			}
 		}
-		put_page(page);
+put_folio:
+		folio_put(folio);
 	}
 	if (!list_empty(&source)) {
 		nodemask_t nmask = node_states[N_MEMORY];
@@ -1853,7 +1839,7 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 		 * We have checked that migration range is on a single zone so
 		 * we can use the nid of the first page to all the others.
 		 */
-		mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru));
+		mtc.nid = folio_nid(list_first_entry(&source, struct folio, lru));
 
 		/*
 		 * try to allocate from a different node but reuse this node
@@ -1866,11 +1852,12 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 		ret = migrate_pages(&source, alloc_migration_target, NULL,
 			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL);
 		if (ret) {
-			list_for_each_entry(page, &source, lru) {
+			list_for_each_entry(folio, &source, lru) {
 				if (__ratelimit(&migrate_rs)) {
 					pr_warn("migrating pfn %lx failed ret:%d\n",
-						page_to_pfn(page), ret);
-					dump_page(page, "migration failure");
+						folio_pfn(folio), ret);
+					dump_page(&folio->page,
+						  "migration failure");
 				}
 			}
 			putback_movable_pages(&source);