memcg: use a folio in get_mctgt_type_thp

Replace five calls to compound_head() with one.

Link: https://lkml.kernel.org/r/20240111181219.3462852-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a5bc34d44dbd50d0076a25b6876d21385a058dcf..db92401257f7d00c4b862016cd7f7e49986f1f0e 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6194,6 +6194,7 @@ static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
                unsigned long addr, pmd_t pmd, union mc_target *target)
 {
        struct page *page = NULL;
+       struct folio *folio;
        enum mc_target_type ret = MC_TARGET_NONE;
 
        if (unlikely(is_swap_pmd(pmd))) {
@@ -6203,17 +6204,18 @@ static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
        }
        page = pmd_page(pmd);
        VM_BUG_ON_PAGE(!page || !PageHead(page), page);
+       folio = page_folio(page);
        if (!(mc.flags & MOVE_ANON))
                return ret;
-       if (page_memcg(page) == mc.from) {
+       if (folio_memcg(folio) == mc.from) {
                ret = MC_TARGET_PAGE;
                if (target) {
-                       get_page(page);
-                       if (!trylock_page(page)) {
-                               put_page(page);
+                       folio_get(folio);
+                       if (!folio_trylock(folio)) {
+                               folio_put(folio);
                                return MC_TARGET_NONE;
                        }
-                       target->folio = page_folio(page);
+                       target->folio = folio;
                }
        }
        return ret;