linux-kernel - [PATCH RFC 4/6] mm/page_alloc: clear PageBuddy using _

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Date: Wed, 22 May 2024 23:03:39 +0200
From: David Hildenbrand <david@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: linux-mm@...ck.org,
	David Hildenbrand <david@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Matthew Wilcox (Oracle)" <willy@...radead.org>,
	Mike Rapoport <rppt@...nel.org>,
	Minchan Kim <minchan@...nel.org>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Hyeonggon Yoo <42.hyeyoo@...il.com>
Subject: [PATCH RFC 4/6] mm/page_alloc: clear PageBuddy using __ClearPageBuddy() for bad pages

Let's stop using page_mapcount_reset() and clear PageBuddy using
__ClearPageBuddy() instead.

Signed-off-by: David Hildenbrand <david@...hat.com>
---
 mm/page_alloc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2e22ce5675ca..b595342e73c2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -498,7 +498,8 @@ static void bad_page(struct page *page, const char *reason)
 	dump_stack();
 out:
 	/* Leave bad fields for debug, except PageBuddy could make trouble */
-	page_mapcount_reset(page); /* remove PageBuddy */
+	if (PageBuddy(page))
+		__ClearPageBuddy(page);
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
 }
 
@@ -1346,7 +1347,8 @@ static void check_new_page_bad(struct page *page)
 {
 	if (unlikely(page->flags & __PG_HWPOISON)) {
 		/* Don't complain about hwpoisoned pages */
-		page_mapcount_reset(page); /* remove PageBuddy */
+		if (PageBuddy(page))
+			__ClearPageBuddy(page);
 		return;
 	}
 
-- 
2.45.0