[PATCH v2 6/8] mm: migrate: use a folio in add_page_for_migration()

From: Kefeng Wang
Date: Mon Aug 21 2023 - 07:45:54 EST


Use a folio in add_page_for_migration() to save compound_head() calls.

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
mm/migrate.c | 40 +++++++++++++++++++---------------------
1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index b715cd59bdec..73572d5a5cd4 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2057,6 +2057,7 @@ static int add_page_for_migration(struct mm_struct *mm, const void __user *p,
struct vm_area_struct *vma;
unsigned long addr;
struct page *page;
+ struct folio *folio;
int err;
bool isolated;

@@ -2079,45 +2080,42 @@ static int add_page_for_migration(struct mm_struct *mm, const void __user *p,
if (!page)
goto out;

- if (is_zone_device_page(page))
- goto out_putpage;
+ folio = page_folio(page);
+ if (folio_is_zone_device(folio))
+ goto out_putfolio;

err = 0;
- if (page_to_nid(page) == node)
- goto out_putpage;
+ if (folio_nid(folio) == node)
+ goto out_putfolio;

err = -EACCES;
if (page_mapcount(page) > 1 && !migrate_all)
- goto out_putpage;
+ goto out_putfolio;

- if (PageHuge(page)) {
+ if (folio_test_hugetlb(folio)) {
if (PageHead(page)) {
- isolated = isolate_hugetlb(page_folio(page), pagelist);
+ isolated = isolate_hugetlb(folio, pagelist);
err = isolated ? 1 : -EBUSY;
}
} else {
- struct page *head;
-
- head = compound_head(page);
- isolated = isolate_lru_page(head);
+ isolated = folio_isolate_lru(folio);
if (!isolated) {
err = -EBUSY;
- goto out_putpage;
+ goto out_putfolio;
}

err = 1;
- list_add_tail(&head->lru, pagelist);
- mod_node_page_state(page_pgdat(head),
- NR_ISOLATED_ANON + page_is_file_lru(head),
- thp_nr_pages(head));
+ list_add_tail(&folio->lru, pagelist);
+ node_stat_mod_folio(folio,
+ NR_ISOLATED_ANON + folio_is_file_lru(folio),
+ folio_nr_pages(folio));
}
-out_putpage:
+out_putfolio:
/*
- * Either remove the duplicate refcount from
- * isolate_lru_page() or drop the page ref if it was
- * not isolated.
+ * Either remove the duplicate refcount from folio_isolate_lru()
+ * or drop the folio ref if it was not isolated.
*/
- put_page(page);
+ folio_put(folio);
out:
mmap_read_unlock(mm);
return err;
--
2.41.0