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From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>, <minchan@kernel.org>, <ngupta@vflare.org>
Cc: <senozhatsky@chromium.org>, <linux-kernel@vger.kernel.org>,
	<linux-mm@kvack.org>, <linmiaohe@huawei.com>
Subject: [PATCH 2/3] mm/zsmalloc.c: combine two atomic ops in zs_pool_dec_isolated()
Date: Thu, 24 Jun 2021 20:39:29 +0800	[thread overview]
Message-ID: <20210624123930.1769093-3-linmiaohe@huawei.com> (raw)
In-Reply-To: <20210624123930.1769093-1-linmiaohe@huawei.com>

atomic_long_dec_and_test() is equivalent to atomic_long_dec() and
atomic_long_read() == 0. Use it to make code more succinct.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 mm/zsmalloc.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 1476289b619f..0b4b23740d78 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1828,13 +1828,12 @@ static void putback_zspage_deferred(struct zs_pool *pool,
 static inline void zs_pool_dec_isolated(struct zs_pool *pool)
 {
 	VM_BUG_ON(atomic_long_read(&pool->isolated_pages) <= 0);
-	atomic_long_dec(&pool->isolated_pages);
 	/*
 	 * There's no possibility of racing, since wait_for_isolated_drain()
 	 * checks the isolated count under &class->lock after enqueuing
 	 * on migration_wait.
 	 */
-	if (atomic_long_read(&pool->isolated_pages) == 0 && pool->destroying)
+	if (atomic_long_dec_and_test(&pool->isolated_pages) && pool->destroying)
 		wake_up_all(&pool->migration_wait);
 }
 
-- 
2.23.0


  parent reply	other threads:[~2021-06-24 12:40 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-24 12:39 [PATCH 0/3] Cleanup for zsmalloc Miaohe Lin
2021-06-24 12:39 ` [PATCH 1/3] mm/zsmalloc.c: remove confusing code in obj_free() Miaohe Lin
2021-06-24 12:39 ` Miaohe Lin [this message]
2021-06-25  5:01   ` [Phishing Risk] [External] [PATCH 2/3] mm/zsmalloc.c: combine two atomic ops in zs_pool_dec_isolated() Muchun Song
2021-06-25  6:32     ` Miaohe Lin
2021-06-25  7:29       ` Muchun Song
2021-06-25  8:46         ` Miaohe Lin
2021-06-25  9:32           ` Miaohe Lin
2021-06-25 10:40             ` Muchun Song
2021-07-01  2:43               ` Miaohe Lin
2021-06-24 12:39 ` [PATCH 3/3] mm/zsmalloc.c: improve readability for async_free_zspage() Miaohe Lin

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