[PATCH 24/31] kthread: Rely on HK_TYPE_DOMAIN for preferred affinity management

[Frederic Weisbecker]

Unbound kthreads want to run neither on nohz_full CPUs nor on domain
isolated CPUs. And since nohz_full implies domain isolation, checking
the latter is enough to verify both.

Therefore exclude kthreads from domain isolation.

Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
---
 kernel/kthread.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 86abfbc21bb0..69d70baceba2 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -362,18 +362,20 @@ static void kthread_fetch_affinity(struct kthread *kthread, struct cpumask *cpum
 {
 	const struct cpumask *pref;
 
+	guard(rcu)();
+
 	if (kthread->preferred_affinity) {
 		pref = kthread->preferred_affinity;
 	} else {
 		if (kthread->node == NUMA_NO_NODE)
-			pref = housekeeping_cpumask(HK_TYPE_KTHREAD);
+			pref = housekeeping_cpumask(HK_TYPE_DOMAIN);
 		else
 			pref = cpumask_of_node(kthread->node);
 	}
 
-	cpumask_and(cpumask, pref, housekeeping_cpumask(HK_TYPE_KTHREAD));
+	cpumask_and(cpumask, pref, housekeeping_cpumask(HK_TYPE_DOMAIN));
 	if (cpumask_empty(cpumask))
-		cpumask_copy(cpumask, housekeeping_cpumask(HK_TYPE_KTHREAD));
+		cpumask_copy(cpumask, housekeeping_cpumask(HK_TYPE_DOMAIN));
 }
 
 static void kthread_affine_node(void)
-- 
2.51.0