From: Chen Ridong <chenridong@huawei.com>
Date: Mon, 22 Sep 2025 13:02:31 +0000 (+0000)
Subject: cpuset: remove redundant special case for null input in node mask update
X-Git-Tag: v6.18-rc1~198^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b72af996b67ccb1dea988765bf046cba2d4c6898;p=thirdparty%2Flinux.git

cpuset: remove redundant special case for null input in node mask update

The nodelist_parse function already handles empty nodemask input
appropriately, making it unnecessary to handle this case separately
during the node mask update process.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 535174ed71268..20dface3c3e0e 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -2847,22 +2847,16 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
 
 	/*
 	 * An empty mems_allowed is ok iff there are no tasks in the cpuset.
-	 * Since nodelist_parse() fails on an empty mask, we special case
-	 * that parsing.  The validate_change() call ensures that cpusets
-	 * with tasks have memory.
+	 * The validate_change() call ensures that cpusets with tasks have memory.
 	 */
-	if (!*buf) {
-		nodes_clear(trialcs->mems_allowed);
-	} else {
-		retval = nodelist_parse(buf, trialcs->mems_allowed);
-		if (retval < 0)
-			goto done;
+	retval = nodelist_parse(buf, trialcs->mems_allowed);
+	if (retval < 0)
+		goto done;
 
-		if (!nodes_subset(trialcs->mems_allowed,
-				  top_cpuset.mems_allowed)) {
-			retval = -EINVAL;
-			goto done;
-		}
+	if (!nodes_subset(trialcs->mems_allowed,
+			  top_cpuset.mems_allowed)) {
+		retval = -EINVAL;
+		goto done;
 	}
 
 	if (nodes_equal(cs->mems_allowed, trialcs->mems_allowed)) {