mm: migrate: introduce a local variable to get the number of pages

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>

diff --git a/mm/migrate.c b/mm/migrate.c
index a0aeb3f..d6617f8 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2107,6 +2107,7 @@ out:
 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);
 
@@ -2115,7 +2116,7 @@ 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))
@@ -2123,7 +2124,7 @@ 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