linux-kernel - [PATCH v4] mm/page_alloc: Consolidate unlikely handling in page_expected

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Message-Id: <20250328014757.1212737-1-ye.liu@linux.dev>
Date: Fri, 28 Mar 2025 09:47:57 +0800
From: Ye Liu <ye.liu@...ux.dev>
To: akpm@...ux-foundation.org
Cc: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Markus.Elfring@....de,
	Ye Liu <liuye@...inos.cn>,
	Sidhartha Kumar <sidhartha.kumar@...cle.com>,
	Anshuman Khandual <anshuman.khandual@....com>
Subject: [PATCH v4] mm/page_alloc: Consolidate unlikely handling in page_expected_state

From: Ye Liu <liuye@...inos.cn>

Consolidate the handling of unlikely conditions in the 
page_expected_state() function to reduce code duplication and improve 
readability.

Move the logic for handling __PG_HWPOISON flags from the 
check_new_page_bad() function to the page_expected_state() function, 
and remove check_new_page_bad().

Call bad_page() directly from the check_new_page() function if the page has
unexpected flags.

Simplify the code by reducing the number of functions and centralizing the
handling of unlikely conditions.

Signed-off-by: Ye Liu <liuye@...inos.cn>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@...cle.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@....com>

---
V4: Use "imperative mood" to modify the commit and append parentheses 
to all function names.
V3: Delete 'This patch'.
V2: return true instead of false in the PageHWPoison branch.
---
 mm/page_alloc.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2842da893eea..e8b95c6a96c2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -903,6 +903,12 @@ static inline bool page_expected_state(struct page *page,
 			(page->flags & check_flags)))
 		return false;
 
+	if (unlikely(PageHWPoison(page))) {
+		/* Don't complain about hwpoisoned pages */
+		if (PageBuddy(page))
+			__ClearPageBuddy(page);
+	}
+
 	return true;
 }
 
@@ -1586,29 +1592,15 @@ static __always_inline void page_del_and_expand(struct zone *zone,
 	account_freepages(zone, -nr_pages, migratetype);
 }
 
-static void check_new_page_bad(struct page *page)
-{
-	if (unlikely(PageHWPoison(page))) {
-		/* Don't complain about hwpoisoned pages */
-		if (PageBuddy(page))
-			__ClearPageBuddy(page);
-		return;
-	}
-
-	bad_page(page,
-		 page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
-}
-
 /*
  * This page is about to be returned from the page allocator
  */
 static bool check_new_page(struct page *page)
 {
-	if (likely(page_expected_state(page,
-				PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON)))
+	if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_PREP)))
 		return false;
 
-	check_new_page_bad(page);
+	bad_page(page, page_bad_reason(page, PAGE_FLAGS_CHECK_AT_PREP));
 	return true;
 }
 
-- 
2.25.1