mm/mempolicy: use a standard migration target allocation callback

There is a well-defined migration target allocation callback.  Use it.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1594622517-20681-7-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/internal.h

@@ -613,7 +613,6 @@ static inline bool is_migrate_highatomic_page(struct page *page)
 }
 
 void setup_zone_pageset(struct zone *zone);
-extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
 
 struct migration_target_control {
 	int nid;		/* preferred node id */

mm/mempolicy.c

@@ -1065,29 +1065,6 @@ static int migrate_page_add(struct page *page, struct list_head *pagelist,
 	return 0;
 }
 
-/* page allocation callback for NUMA node migration */
-struct page *alloc_new_node_page(struct page *page, unsigned long node)
-{
-	if (PageHuge(page)) {
-		struct hstate *h = page_hstate(compound_head(page));
-		gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
-
-		return alloc_huge_page_nodemask(h, node, NULL, gfp_mask);
-	} else if (PageTransHuge(page)) {
-		struct page *thp;
-
-		thp = alloc_pages_node(node,
-			(GFP_TRANSHUGE | __GFP_THISNODE),
-			HPAGE_PMD_ORDER);
-		if (!thp)
-			return NULL;
-		prep_transhuge_page(thp);
-		return thp;
-	} else
-		return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE |
-						    __GFP_THISNODE, 0);
-}
-
 /*
  * Migrate pages from one node to a target node.
  * Returns error or the number of pages not migrated.
@@ -1098,6 +1075,10 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
 	nodemask_t nmask;
 	LIST_HEAD(pagelist);
 	int err = 0;
+	struct migration_target_control mtc = {
+		.nid = dest,
+		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
+	};
 
 	nodes_clear(nmask);
 	node_set(source, nmask);
@@ -1112,8 +1093,8 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
 			flags | MPOL_MF_DISCONTIG_OK, &pagelist);
 
 	if (!list_empty(&pagelist)) {
-		err = migrate_pages(&pagelist, alloc_new_node_page, NULL, dest,
-					MIGRATE_SYNC, MR_SYSCALL);
+		err = migrate_pages(&pagelist, alloc_migration_target, NULL,
+				(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL);
 		if (err)
 			putback_movable_pages(&pagelist);
 	}

mm/migrate.c

@@ -1598,9 +1598,13 @@ static int do_move_pages_to_node(struct mm_struct *mm,
 		struct list_head *pagelist, int node)
 {
 	int err;
+	struct migration_target_control mtc = {
+		.nid = node,
+		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
+	};
 
-	err = migrate_pages(pagelist, alloc_new_node_page, NULL, node,
-			MIGRATE_SYNC, MR_SYSCALL);
+	err = migrate_pages(pagelist, alloc_migration_target, NULL,
+			(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL);
 	if (err)
 		putback_movable_pages(pagelist);
 	return err;