[PATCH v5 10/12] cpuset: use partition_disable() to invalidate local partition

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

From: Ridong Chen <chenridong@xiaomi.com>

Use partition_disable() to handle local partition invalidation as well,
replacing partcmd_invalidate in partition_cpus_change(). An invalid
partition has already given back its CPUs, so partition_cpus_change()
leaves it alone. cpuset_hotplug_update_tasks() is converted later
together with the partition revival, by local_partition_update().

As partition_disable() resets the partition data, the
effective_xcpus of an invalid partition is no longer kept. When
update_parent_effective_cpumask() turns an invalid partition back into
a valid one, use partition_enable() to set up effective_xcpus and the
partition state again.

Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
---
 kernel/cgroup/cpuset.c | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 211567c61e95..038bed1f4fb8 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -2367,20 +2367,28 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
 	 * Newly added CPUs will be removed from effective_cpus and
 	 * newly deleted ones will be added back to effective_cpus.
 	 */
-	spin_lock_irq(&callback_lock);
-	if (old_prs != new_prs)
-		cs->partition_root_state = new_prs;
+	if (old_prs < 0 && new_prs > 0) {
+		/*
+		 * An invalid partition becomes valid again, its effective_xcpus
+		 * was cleared or recomputed when it was invalidated.
+		 */
+		partition_enable(cs, parent, new_prs, tmp->delmask);
+	} else {
+		spin_lock_irq(&callback_lock);
+		if (old_prs != new_prs)
+			cs->partition_root_state = new_prs;
 
-	/*
-	 * Adding to parent's effective_cpus means deletion CPUs from cs
-	 * and vice versa.
-	 */
-	if (adding)
-		partition_xcpus_del(old_prs, parent, tmp->addmask);
-	if (deleting)
-		partition_xcpus_add(new_prs, parent, tmp->delmask);
+		/*
+		 * Adding to parent's effective_cpus means deletion CPUs from cs
+		 * and vice versa.
+		 */
+		if (adding)
+			partition_xcpus_del(old_prs, parent, tmp->addmask);
+		if (deleting)
+			partition_xcpus_add(new_prs, parent, tmp->delmask);
 
-	spin_unlock_irq(&callback_lock);
+		spin_unlock_irq(&callback_lock);
+	}
 
 	if (adding || deleting) {
 		cpuset_update_tasks_cpumask(parent, tmp->addmask);
@@ -2684,12 +2692,12 @@ static void partition_cpus_change(struct cpuset *cs, struct cpuset *trialcs,
 			remote_cpus_update(cs, trialcs->exclusive_cpus,
 					   trialcs->effective_xcpus, tmp);
 	} else {
-		if (trialcs->prs_err)
-			update_parent_effective_cpumask(cs, partcmd_invalidate,
-							NULL, tmp);
-		else
+		if (!trialcs->prs_err)
 			update_parent_effective_cpumask(cs, partcmd_update,
 							trialcs->effective_xcpus, tmp);
+		else if (is_partition_valid(cs))
+			partition_disable(cs, -cs->partition_root_state,
+					  trialcs->prs_err, tmp);
 	}
 }
 
-- 
2.34.1