[PATCH v2 2/4] mm: migrate: Introduce a local variable to get the number of pages

[Baolin Wang <baolin.wang@linux.alibaba.com>]

Use thp_nr_pages() instead of compound_nr() to get the number of pages
for THP page, meanwhile introducing a local variable 'nr_pages' to
avoid getting the number of pages repeatedly.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
---
 mm/migrate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 8e9282f..9b162c0e 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2106,6 +2106,7 @@ static struct page *alloc_misplaced_dst_page_thp(struct page *page,
 static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 {
 	int page_lru;
+	int nr_pages = thp_nr_pages(page);
 
 	VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page);
 
@@ -2114,7 +2115,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 		return 0;
 
 	/* Avoid migrating to a node that is nearly full */
-	if (!migrate_balanced_pgdat(pgdat, compound_nr(page)))
+	if (!migrate_balanced_pgdat(pgdat, nr_pages))
 		return 0;
 
 	if (isolate_lru_page(page))
@@ -2122,7 +2123,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 
 	page_lru = page_is_file_lru(page);
 	mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru,
-				thp_nr_pages(page));
+			    nr_pages);
 
 	/*
 	 * Isolating the page has taken another reference, so the
-- 
1.8.3.1