diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index dc33ba5..07dfb99 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -619,11 +619,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
 	 * code gets preempted or delayed for some reason.
 	 */
 	for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
-		/* Disable preemption to make it very likely to
-		 * succeed in the first iteration even on PREEMPT_RT kernel.
-		 */
-		preempt_disable();
-
 		/* Get system timestamp before query. */
 		do_gettimeofday(&stime);
 
@@ -633,8 +628,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
 		/* Get system timestamp after query. */
 		do_gettimeofday(&raw_time);
 
-		preempt_enable();
-
 		/* Return as no-op if scanout query unsupported or failed. */
 		if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
 			DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
index 6f61d5f..d2676b8 100644
--- a/drivers/misc/hwlat_detector.c
+++ b/drivers/misc/hwlat_detector.c
@@ -413,7 +413,7 @@ static int init_stats(void)
 		goto out;
 
 	__reset_stats();
-	data.threshold = DEFAULT_LAT_THRESHOLD;	    /* threshold us */
+	data.threshold = threshold ?: DEFAULT_LAT_THRESHOLD;	    /* threshold us */
 	data.sample_window = DEFAULT_SAMPLE_WINDOW; /* window us */
 	data.sample_width = DEFAULT_SAMPLE_WIDTH;   /* width us */
 
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index a6bea19..30211a7 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1024,7 +1024,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 			goto out_mput;
 		}
 
-		sched_setscheduler(t, SCHED_FIFO, &param);
+		sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
 
 		/*
 		 * We keep the reference to the task struct even if
diff --git a/localversion-rt b/localversion-rt
index 168858f..0e811ca 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt85
+-rt86
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9c36442..107c0ba 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2082,7 +2082,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
 
 	/* Notify other cpus that system-wide "drain" is running */
 	get_online_cpus();
-	curcpu = get_cpu();
+	curcpu = get_cpu_light();
 	for_each_online_cpu(cpu) {
 		struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
 		struct mem_cgroup *memcg;
@@ -2099,7 +2099,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
 				schedule_work_on(cpu, &stock->work);
 		}
 	}
-	put_cpu();
+	put_cpu_light();
 
 	if (!sync)
 		goto out;
