[PATCHv5 17/17] mm/slab: Use compound_head() in page_slab()

[Kiryl Shutsemau]

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

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

Signed-off-by: Kiryl Shutsemau <kas at kernel.org>

---

I am not sure if this open-coded version is intentional and required for
memdesc transition. Drop the patch if it is.
---
 mm/slab.h | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/mm/slab.h b/mm/slab.h
index f68c3ac8126f..970a13ac5b8e 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -137,19 +137,7 @@ 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;
 
-- 
2.51.2