mm/page_alloc: remove a wrapper for alloc_migration_target()

There is a well-defined standard migration target callback.  Use it
directly.
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/1594622517-20681-8-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

@@ -8347,6 +8347,10 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
 	unsigned long pfn = start;
 	unsigned int tries = 0;
 	int ret = 0;
+	struct migration_target_control mtc = {
+		.nid = zone_to_nid(cc->zone),
+		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
+	};
 
 	migrate_prep();
 
@@ -8373,8 +8377,8 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
 							&cc->migratepages);
 		cc->nr_migratepages -= nr_reclaimed;
 
-		ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
-				    NULL, 0, cc->mode, MR_CONTIG_RANGE);
+		ret = migrate_pages(&cc->migratepages, alloc_migration_target,
+				NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE);
 	}
 	if (ret < 0) {
 		putback_movable_pages(&cc->migratepages);

mm/page_isolation.c

@@ -306,13 +306,3 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
 
 	return pfn < end_pfn ? -EBUSY : 0;
 }
-
-struct page *alloc_migrate_target(struct page *page, unsigned long private)
-{
-	struct migration_target_control mtc = {
-		.nid = page_to_nid(page),
-		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
-	};
-
-	return alloc_migration_target(page, (unsigned long)&mtc);
-}