From 4357e428d2033ca70954808e066f249d433deb69 Mon Sep 17 00:00:00 2001
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Wed, 8 Sep 2021 15:18:01 -0700
Subject: [PATCH] mm: migrate: introduce a local variable to get the number of
 pages

References: bsc#1190208 (MM functional and performance backports)
Patch-mainline: v5.15-rc1
Git-commit: 2b9b624f5aef6af608edf541fed973948e27004c

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.

Link: https://lkml.kernel.org/r/a8e331ac04392ee230c79186330fb05e86a2aa77.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 mm/migrate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 7e240437e7d9..533bd7021315 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2027,6 +2027,7 @@ 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);
 
@@ -2035,7 +2036,7 @@ 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))
@@ -2043,7 +2044,7 @@ 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