From: David Hildenbrand <david@redhat.com>
Date: Wed, 29 May 2024 11:19:02 +0000 (+0200)
Subject: mm/page_alloc: clear PageBuddy using __ClearPageBuddy() for bad pages
X-Git-Tag: v6.11-rc1~85^2~234
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e4d970acfb1e7d1e83ce3101dc3c01eae44938e1;p=thirdparty%2Fkernel%2Fstable.git

mm/page_alloc: clear PageBuddy using __ClearPageBuddy() for bad pages

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

Link: https://lkml.kernel.org/r/20240529111904.2069608-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>	[zram/zsmalloc workloads]
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0576ac081a1fe..8d7b4424b6453 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);
 }
 
@@ -1351,7 +1352,8 @@ 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;
 	}