diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 43c2bcc35761e40c9342522b4fa87b92cdefd8f4..b30a2924ef1429a60152a40101ec4828c5e23268 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -301,14 +301,14 @@ u64 sched_clock_cpu(int cpu)
 	if (unlikely(!sched_clock_running))
 		return 0ull;
 
-	preempt_disable();
+	preempt_disable_notrace();
 	scd = cpu_sdc(cpu);
 
 	if (cpu != smp_processor_id())
 		clock = sched_clock_remote(scd);
 	else
 		clock = sched_clock_local(scd);
-	preempt_enable();
+	preempt_enable_notrace();
 
 	return clock;
 }
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6edbef296ece25a6ee68facac279445414692368..f5c6635b806c56550bcee17aa0c2490c96b16ff7 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3338,6 +3338,15 @@ static int __sched_setscheduler(struct task_struct *p,
 				return -EPERM;
 		}
 
+		 /*
+		  * Can't set/change SCHED_DEADLINE policy at all for now
+		  * (safest behavior); in the future we would like to allow
+		  * unprivileged DL tasks to increase their relative deadline
+		  * or reduce their runtime (both ways reducing utilization)
+		  */
+		if (dl_policy(policy))
+			return -EPERM;
+
 		/*
 		 * Treat SCHED_IDLE as nice 20. Only allow a switch to
 		 * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 84571e09c9079e8887f73a0f24beefe58e00ff77..01fbae5b97b765199feccfbb6f985c1309dc3475 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -293,7 +293,7 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 	 */
 	smp_call_function_single(min(cpu1, cpu2),
 				 &irq_cpu_stop_queue_work,
-				 &call_args, 0);
+				 &call_args, 1);
 	lg_local_unlock(&stop_cpus_lock);
 	preempt_enable();