From: Kiryl Shutsemau <kas@kernel.org>
Date: Fri, 27 Feb 2026 19:42:56 +0000 (+0000)
Subject: mm/slab: use compound_head() in page_slab()
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8231e4c040fb0ddd37d66093281d197fd5000297;p=thirdparty%2Fkernel%2Flinux.git

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 ccbdbed18c052..77242024e7d51 100644
--- 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;