mm/page_isolation: prefer the node of the source page

Patch series "clean-up the migration target allocation functions", v5.

This patch (of 9):

For locality, it's better to migrate the page to the same node rather than
the node of the current caller's cpu.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Link: http://lkml.kernel.org/r/1594622517-20681-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1594622517-20681-2-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_isolation.c

@@ -309,5 +309,7 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
 
 struct page *alloc_migrate_target(struct page *page, unsigned long private)
 {
-	return new_page_nodemask(page, numa_node_id(), &node_states[N_MEMORY]);
+	int nid = page_to_nid(page);
+
+	return new_page_nodemask(page, nid, &node_states[N_MEMORY]);
 }