From: Dmitry Ilvokhin <d@ilvokhin.com>
Date: Wed, 29 Apr 2026 12:02:10 +0000 (+0000)
Subject: mm: use zone lock guard in take_page_off_buddy()
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=ee8a0c15c26f6cf67e4e5207cb18e6262d7e886e;p=thirdparty%2Flinux.git

mm: use zone lock guard in take_page_off_buddy()

Use spinlock_irqsave zone lock guard in take_page_off_buddy() to replace
the explicit lock/unlock pattern with automatic scope-based cleanup.

This also allows to return directly from the loop, removing the 'ret'
variable.

Link: https://lore.kernel.org/a981721632a981f148c63e3f7df3d1116a0c3f6d.1777462630.git.d@ilvokhin.com
Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 56ba22e1a816..f5ad74490c5d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7644,11 +7644,9 @@ bool take_page_off_buddy(struct page *page)
 {
 	struct zone *zone = page_zone(page);
 	unsigned long pfn = page_to_pfn(page);
-	unsigned long flags;
 	unsigned int order;
-	bool ret = false;
 
-	spin_lock_irqsave(&zone->lock, flags);
+	guard(spinlock_irqsave)(&zone->lock);
 	for (order = 0; order < NR_PAGE_ORDERS; order++) {
 		struct page *page_head = page - (pfn & ((1 << order) - 1));
 		int page_order = buddy_order(page_head);
@@ -7663,14 +7661,12 @@ bool take_page_off_buddy(struct page *page)
 			break_down_buddy_pages(zone, page_head, page, 0,
 						page_order, migratetype);
 			SetPageHWPoisonTakenOff(page);
-			ret = true;
-			break;
+			return true;
 		}
 		if (page_count(page_head) > 0)
 			break;
 	}
-	spin_unlock_irqrestore(&zone->lock, flags);
-	return ret;
+	return false;
 }
 
 /*