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From:   Liu Shixin <liushixin2@huawei.com>
To:     Seth Jennings <sjenning@redhat.com>,
        Dan Streetman <ddstreet@ieee.org>,
        Vitaly Wool <vitaly.wool@konsulko.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Christoph Hellwig <hch@lst.de>
CC:     <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        Liu Shixin <liushixin2@huawei.com>
Subject: [PATCH -next v6 1/2] mm/zswap: skip invalid or unchanged parameter
Date:   Wed, 22 Mar 2023 18:20:05 +0800
Message-ID: <20230322102006.780624-2-liushixin2@huawei.com>
In-Reply-To: <20230322102006.780624-1-liushixin2@huawei.com>
References: <20230322102006.780624-1-liushixin2@huawei.com>
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If parameter is invalid or no change required, return directly. This can
reduces unnecessary printing.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
---
 mm/zswap.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mm/zswap.c b/mm/zswap.c
index 2f0ebd8bc620..09fa956920fa 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -875,6 +875,15 @@ static int zswap_zpool_param_set(const char *val,
 static int zswap_enabled_param_set(const char *val,
 				   const struct kernel_param *kp)
 {
+	bool res;
+
+	if (kstrtobool(val, &res))
+		return -EINVAL;
+
+	/* no change required */
+	if (res == *(bool *)kp->arg)
+		return 0;
+
 	if (zswap_init_failed) {
 		pr_err("can't enable, initialization failed\n");
 		return -ENODEV;
-- 
2.25.1