[RFC PATCH -v4 11/22] cpuset: introduce local_partition_disable()

[Ridong Chen <ridong.chen@linux.dev>]

From: Chen Ridong <chenridong@huawei.com>

The partition_disable() function introduced earlier can be extended to
handle local partition disablement.

The local_partition_disable() function is introduced, which extracts the
local partition disable logic from update_parent_effective_cpumask(). It
calls partition_disable() to complete the disablement process.

This refactoring establishes a clear separation between local and remote
partition operations while promoting code reuse through the shared
partition_disable() infrastructure.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
---
 kernel/cgroup/cpuset.c | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 847713110738..3d6ad6cd634a 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -2049,6 +2049,31 @@ static int local_partition_enable(struct cpuset *cs,
 	return 0;
 }
 
+/**
+ * local_partition_disable - Disable a local partition
+ * @cs: Target cpuset (local partition root) to disable
+ * @part_error: partition error when @cs is disabled
+ * @tmp: Temporary masks for CPU calculations
+ */
+static void local_partition_disable(struct cpuset *cs, enum prs_errcode part_error,
+				    struct tmpmasks *tmp)
+{
+	struct cpuset *parent = parent_cs(cs);
+	int new_prs;
+
+	lockdep_assert_cpuset_lock_held();
+	WARN_ON_ONCE(is_remote_partition(cs));	/* For local partition only */
+
+	if (!is_partition_valid(cs))
+		return;
+
+	new_prs = part_error ? -cs->partition_root_state : PRS_MEMBER;
+	partition_disable(cs, parent, new_prs, part_error);
+
+	cpuset_update_tasks_cpumask(parent, tmp->addmask);
+	update_sibling_cpumasks(parent, cs, tmp);
+}
+
 /**
  * update_parent_effective_cpumask - update effective_cpus mask of parent cpuset
  * @cs:      The cpuset that requests change in partition root state
@@ -2147,18 +2172,7 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
 		nocpu = tasks_nocpu_error(parent, cs, tmp->delmask);
 	}
 
-	if (cmd == partcmd_disable) {
-		/*
-		 * May need to add cpus back to parent's effective_cpus
-		 * (and maybe removed from subpartitions_cpus/isolated_cpus)
-		 * for valid partition root.
-		 */
-		if (is_partition_valid(cs)) {
-			cpumask_copy(tmp->addmask, cs->effective_xcpus);
-			adding = true;
-		}
-		new_prs = PRS_MEMBER;
-	} else if (newmask) {
+	if (newmask) {
 		/*
 		 * Empty cpumask is not allowed
 		 */
@@ -3158,9 +3172,7 @@ static int update_prstate(struct cpuset *cs, int new_prs)
 		if (is_remote_partition(cs))
 			remote_partition_disable(cs, &tmpmask);
 		else
-			update_parent_effective_cpumask(cs, partcmd_disable,
-							NULL, &tmpmask);
-
+			local_partition_disable(cs, PERR_NONE, &tmpmask);
 		/*
 		 * Invalidation of child partitions will be done in
 		 * update_cpumasks_hier() below.
-- 
2.34.1