linux-kernel - [PATCH v2 4/8] mm: swap: use swap_entries_free() drop last ref count in swap_entries_put

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Message-Id: <20250318150614.6415-5-shikemeng@huaweicloud.com>
Date: Tue, 18 Mar 2025 23:06:10 +0800
From: Kemeng Shi <shikemeng@...weicloud.com>
To: akpm@...ux-foundation.org
Cc: tim.c.chen@...ux.intel.com,
	ryncsn@...il.com,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v2 4/8] mm: swap: use swap_entries_free() drop last ref count in swap_entries_put_nr()

Use swap_entries_free() to directly free swap entries when the swap
entries are not cached and referenced, without needing to set swap
entries to set intermediate SWAP_HAS_CACHE state.

Signed-off-by: Kemeng Shi <shikemeng@...weicloud.com>
Reviewed-by: Tim Chen <tim.c.chen@...ux.intel.com>
---
 mm/swapfile.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 40e41e514813..2a08d9e89f90 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1490,10 +1490,11 @@ static bool swap_entries_put_nr(struct swap_info_struct *si,
 		unlock_cluster(ci);
 		goto fallback;
 	}
-	for (i = 0; i < nr; i++)
-		WRITE_ONCE(si->swap_map[offset + i], SWAP_HAS_CACHE);
 	if (!has_cache)
 		swap_entries_free(si, ci, entry, nr);
+	else
+		for (i = 0; i < nr; i++)
+			WRITE_ONCE(si->swap_map[offset + i], SWAP_HAS_CACHE);
 	unlock_cluster(ci);
 
 	return has_cache;
-- 
2.30.0