linux-kernel - [PATCH 1/2] mm/zsmalloc: fix class per-fullness zspage counts

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Date: Thu, 27 Jun 2024 15:59:58 +0800
From: Chengming Zhou <chengming.zhou@...ux.dev>
To: minchan@...nel.org,
	senozhatsky@...omium.org,
	akpm@...ux-foundation.org
Cc: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	chengming.zhou@...ux.dev
Subject: [PATCH 1/2] mm/zsmalloc: fix class per-fullness zspage counts

We always use insert_zspage() and remove_zspage() to update zspage's
fullness location, which will account correctly.

But this special async free path use "splice" instead of remove_zspage(),
so the per-fullness zspage count for ZS_INUSE_RATIO_0 won't decrease.

Fix it by decreasing when iterate over the zspage free list.

Signed-off-by: Chengming Zhou <chengming.zhou@...ux.dev>
---
 mm/zsmalloc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index fec1a39e5bbe..7fc25fa4e6b3 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1883,6 +1883,7 @@ static void async_free_zspage(struct work_struct *work)
 
 		class = zspage_class(pool, zspage);
 		spin_lock(&class->lock);
+		class_stat_dec(class, ZS_INUSE_RATIO_0, 1);
 		__free_zspage(pool, class, zspage);
 		spin_unlock(&class->lock);
 	}
-- 
2.20.1