memcg: use a folio in get_mctgt_type

Replace seven calls to compound_head() with one.  We still use the page as
page_mapped() is different from folio_mapped().

Link: https://lkml.kernel.org/r/20240111181219.3462852-4-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 f52cbc42359e5e549250f365f31d4b15233ebd32..a5bc34d44dbd50d0076a25b6876d21385a058dcf 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6109,6 +6109,7 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
                unsigned long addr, pte_t ptent, union mc_target *target)
 {
        struct page *page = NULL;
+       struct folio *folio;
        enum mc_target_type ret = MC_TARGET_NONE;
        swp_entry_t ent = { .val = 0 };
 
@@ -6123,9 +6124,11 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
        else if (is_swap_pte(ptent))
                page = mc_handle_swap_pte(vma, ptent, &ent);
 
+       if (page)
+               folio = page_folio(page);
        if (target && page) {
-               if (!trylock_page(page)) {
-                       put_page(page);
+               if (!folio_trylock(folio)) {
+                       folio_put(folio);
                        return ret;
                }
                /*
@@ -6140,8 +6143,8 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
                 * Alas, skip moving the page in this case.
                 */
                if (!pte_present(ptent) && page_mapped(page)) {
-                       unlock_page(page);
-                       put_page(page);
+                       folio_unlock(folio);
+                       folio_put(folio);
                        return ret;
                }
        }
@@ -6154,18 +6157,18 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
                 * mem_cgroup_move_account() checks the page is valid or
                 * not under LRU exclusion.
                 */
-               if (page_memcg(page) == mc.from) {
+               if (folio_memcg(folio) == mc.from) {
                        ret = MC_TARGET_PAGE;
-                       if (is_device_private_page(page) ||
-                           is_device_coherent_page(page))
+                       if (folio_is_device_private(folio) ||
+                           folio_is_device_coherent(folio))
                                ret = MC_TARGET_DEVICE;
                        if (target)
-                               target->folio = page_folio(page);
+                               target->folio = folio;
                }
                if (!ret || !target) {
                        if (target)
-                               unlock_page(page);
-                       put_page(page);
+                               folio_unlock(folio);
+                       folio_put(folio);
                }
        }
        /*