From 2a0b4a45cea8d3c17ada4d24f3753e6efff1f4ef Mon Sep 17 00:00:00 2001
From: Liu Shixin <liushixin2@huawei.com>
Date: Thu, 25 Aug 2022 22:20:37 +0800
Subject: [PATCH] mm/zswap: skip confusing print info

It's confusing when we disable zswap while zswap is init failed or has no
pool.  If no change required, just return directly.

Link: https://lkml.kernel.org/r/20220825142037.3214152-4-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/zswap.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mm/zswap.c b/mm/zswap.c
index 4c476c463035..ef7463550e49 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -886,6 +886,15 @@ 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 (system_state == SYSTEM_RUNNING) {
 		mutex_lock(&zswap_init_lock);
 		if (zswap_setup()) {
-- 
2.50.1