diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 533547e3c90a..66457d4b8965 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7311,13 +7311,19 @@ static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpu
/*
* Scan the local SMT mask for idle CPUs.
*/
-static int select_idle_smt(struct task_struct *p, int target)
+static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target)
{
int cpu;
for_each_cpu_and(cpu, cpu_smt_mask(target), p->cpus_ptr) {
if (cpu == target)
continue;
+ /*
+ * Check if the CPU is in the LLC scheduling domain of @target.
+ * Due to isolcpus, there is no guarantee that all the siblings are in the domain.
+ */
+ if (!cpumask_test_cpu(cpu, sched_domain_span(sd)))
commit df3cb4ea1fb6 ("sched/fair: Fix wrong cpu selecting from isolated domain")
also checked if (!cpumask_test_cpu(cpu, p->cpus_ptr) ||
Why didn't you also re-add this test ?