mm/slab: use compound_head() in page_slab()

page_slab() contained an open-coded implementation of compound_head().

Replace the duplicated code with a direct call to compound_head().

Link: https://lkml.kernel.org/r/20260227194302.274384-19-kas@kernel.org
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baoquan He <bhe@redhat.com>
Cc: Christoph Lameter <cl@gentwo.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/slab.h b/mm/slab.h
index ccbdbed18c052b0d76f8b713465cd30b9367a109..77242024e7d51b76a68536ecae3ae5fc765d31c8 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -131,19 +131,7 @@ static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(struct freelist
  */
 static inline struct slab *page_slab(const struct page *page)
 {
-       unsigned long info;
-
-       info = READ_ONCE(page->compound_info);
-       if (info & 1) {
-               /* See compound_head() */
-               if (compound_info_has_mask()) {
-                       unsigned long p = (unsigned long)page;
-                       page = (struct page *)(p & info);
-               } else {
-                       page = (struct page *)(info - 1);
-               }
-       }
-
+       page = compound_head(page);
        if (data_race(page->page_type >> 24) != PGTY_slab)
                page = NULL;