[RFC PATCH -v4 17/22] cpuset: use partition_disable for compute_partition_effective_cpumask

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

From: Chen Ridong <chenridong@huawei.com>

Replace the partition invalidation logic in the
compute_partition_effective_cpumask() with a call to partition_disable().

This centralizes partition state management and ensures consistent
handling of partition disable operations throughout the cpuset subsystem.
The isolated_cpus update that was open-coded here is now done by
partition_xcpus_del() called from partition_disable(). In addition,
partition_disable() gives the exclusive CPUs of the invalidated child
back to the parent and resets the partition data of the child, the
same as other partition invalidation paths.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
---
 kernel/cgroup/cpuset.c | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 00afa4987381..af42666d4530 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1137,6 +1137,8 @@ void cpuset_update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus)
 
 static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
 				    struct tmpmasks *tmp);
+static void partition_disable(struct cpuset *cs, struct cpuset *parent,
+			      int new_prs, enum prs_errcode prs_err);
 
 /*
  * Update partition load balance flag and/or rebuild sched domain
@@ -1642,20 +1644,9 @@ static void compute_partition_effective_cpumask(struct cpuset *cs,
 		 */
 		WARN_ON_ONCE(is_remote_partition(child));
 		if (populated && cpumask_subset(new_ecpus, child->effective_xcpus)) {
-			int old_prs = child->partition_root_state;
-			int parent_prs = cs->partition_root_state;
-
-			/*
-			 * Invalidate child partition. Its CPUs, including those
-			 * further distributed to its descendants, take the
-			 * isolation state of cs.
-			 */
-			spin_lock_irq(&callback_lock);
-			WRITE_ONCE(child->prs_err, PERR_NOCPUS);
-			isolated_cpus_set_state(parent_prs, child->effective_xcpus);
-			child->partition_root_state = -old_prs;
-			spin_unlock_irq(&callback_lock);
-			notify_partition_change(child, old_prs);
+			/* Invalidate child partition */
+			partition_disable(child, cs, -child->partition_root_state,
+					  PERR_NOCPUS);
 			continue;
 		}
 		cpumask_andnot(new_ecpus, new_ecpus,
-- 
2.34.1