1 files changed, 43 insertions, 15 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index b7e9d8f8f649..809df16c7c0d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1533,21 +1533,34 @@ static void folio_check_dirty_writeback(struct folio *folio,
 		mapping->a_ops->is_dirty_writeback(folio, dirty, writeback);
 }
 
-static struct page *alloc_demote_page(struct page *page, unsigned long node)
+static struct page *alloc_demote_page(struct page *page, unsigned long private)
 {
-	struct migration_target_control mtc = {
-		/*
-		 * Allocate from 'node', or fail quickly and quietly.
-		 * When this happens, 'page' will likely just be discarded
-		 * instead of migrated.
-		 */
-		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) |
-			    __GFP_THISNODE  | __GFP_NOWARN |
-			    __GFP_NOMEMALLOC | GFP_NOWAIT,
-		.nid = node
-	};
+	struct page *target_page;
+	nodemask_t *allowed_mask;
+	struct migration_target_control *mtc;
+
+	mtc = (struct migration_target_control *)private;
+
+	allowed_mask = mtc->nmask;
+	/*
+	 * make sure we allocate from the target node first also trying to
+	 * demote or reclaim pages from the target node via kswapd if we are
+	 * low on free memory on target node. If we don't do this and if
+	 * we have free memory on the slower(lower) memtier, we would start
+	 * allocating pages from slower(lower) memory tiers without even forcing
+	 * a demotion of cold pages from the target memtier. This can result
+	 * in the kernel placing hot pages in slower(lower) memory tiers.
+	 */
+	mtc->nmask = NULL;
+	mtc->gfp_mask |= __GFP_THISNODE;
+	target_page = alloc_migration_target(page, (unsigned long)mtc);
+	if (target_page)
+		return target_page;
 
-	return alloc_migration_target(page, (unsigned long)&mtc);
+	mtc->gfp_mask &= ~__GFP_THISNODE;
+	mtc->nmask = allowed_mask;
+
+	return alloc_migration_target(page, (unsigned long)mtc);
 }
 
 /*
@@ -1560,6 +1573,19 @@ static unsigned int demote_page_list(struct list_head *demote_pages,
 {
 	int target_nid = next_demotion_node(pgdat->node_id);
 	unsigned int nr_succeeded;
+	nodemask_t allowed_mask;
+
+	struct migration_target_control mtc = {
+		/*
+		 * Allocate from 'node', or fail quickly and quietly.
+		 * When this happens, 'page' will likely just be discarded
+		 * instead of migrated.
+		 */
+		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) | __GFP_NOWARN |
+			__GFP_NOMEMALLOC | GFP_NOWAIT,
+		.nid = target_nid,
+		.nmask = &allowed_mask
+	};
 
 	if (list_empty(demote_pages))
 		return 0;
@@ -1567,10 +1593,12 @@ static unsigned int demote_page_list(struct list_head *demote_pages,
 	if (target_nid == NUMA_NO_NODE)
 		return 0;
 
+	node_get_allowed_targets(pgdat, &allowed_mask);
+
 	/* Demotion ignores all cpuset and mempolicy settings */
 	migrate_pages(demote_pages, alloc_demote_page, NULL,
-			    target_nid, MIGRATE_ASYNC, MR_DEMOTION,
-			    &nr_succeeded);
+		      (unsigned long)&mtc, MIGRATE_ASYNC, MR_DEMOTION,
+		      &nr_succeeded);
 
 	if (current_is_kswapd())
 		__count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded);