diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c
index 5c93ffc..ddbd223 100644
--- a/fs/jbd/checkpoint.c
+++ b/fs/jbd/checkpoint.c
@@ -129,6 +129,8 @@ void __log_wait_for_space(journal_t *journal)
 		if (journal->j_flags & JFS_ABORT)
 			return;
 		spin_unlock(&journal->j_state_lock);
+		if (current->plug)
+			io_schedule();
 		mutex_lock(&journal->j_checkpoint_mutex);
 
 		/*
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 0e37086..7408760 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -113,6 +113,9 @@ struct hrtimer {
 	unsigned long			state;
 	struct list_head		cb_entry;
 	int				irqsafe;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	ktime_t 			praecox;
+#endif
 #ifdef CONFIG_TIMER_STATS
 	int				start_pid;
 	void				*start_site;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1f6b11a..0174e3a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1585,7 +1585,7 @@ struct task_struct {
 #ifdef CONFIG_WAKEUP_LATENCY_HIST
 	u64 preempt_timestamp_hist;
 #ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
-	unsigned long timer_offset;
+	long timer_offset;
 #endif
 #endif
 #endif /* CONFIG_TRACING */
diff --git a/init/Kconfig b/init/Kconfig
index dbc82d0..720c182 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -731,6 +731,7 @@ config RT_GROUP_SCHED
 	bool "Group scheduling for SCHED_RR/FIFO"
 	depends on EXPERIMENTAL
 	depends on CGROUP_SCHED
+	depends on !PREEMPT_RT_FULL
 	default n
 	help
 	  This feature lets you explicitly allocate real CPU bandwidth
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 58690af..4d9159a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5420,6 +5420,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event)
 
 	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hwc->hrtimer.function = perf_swevent_hrtimer;
+	hwc->hrtimer.irqsafe = 1;
 
 	/*
 	 * Since hrtimers have a fixed rate, we can do a static freq->period
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 3991464..a080e62 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1021,6 +1021,17 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 #endif
 	}
 
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	{
+		ktime_t now = new_base->get_time();
+
+		if (ktime_to_ns(tim) < ktime_to_ns(now))
+			timer->praecox = now;
+		else
+			timer->praecox = ktime_set(0, 0);
+	}
+#endif
+
 	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
 
 	timer_stats_hrtimer_set_start_info(timer);
@@ -1458,8 +1469,9 @@ retry:
 			timer = container_of(node, struct hrtimer, node);
 
 			trace_hrtimer_interrupt(raw_smp_processor_id(),
-			    ktime_to_ns(ktime_sub(
-				hrtimer_get_expires(timer), basenow)),
+			    ktime_to_ns(ktime_sub(ktime_to_ns(timer->praecox) ?
+				timer->praecox : hrtimer_get_expires(timer),
+				basenow)),
 			    current,
 			    timer->function == hrtimer_wakeup ?
 			    container_of(timer, struct hrtimer_sleeper,
diff --git a/kernel/trace/latency_hist.c b/kernel/trace/latency_hist.c
index 9d49fcb..6a4c869 100644
--- a/kernel/trace/latency_hist.c
+++ b/kernel/trace/latency_hist.c
@@ -27,6 +27,8 @@
 #include "trace.h"
 #include <trace/events/sched.h>
 
+#define NSECS_PER_USECS 1000L
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/hist.h>
 
@@ -46,11 +48,11 @@ enum {
 struct hist_data {
 	atomic_t hist_mode; /* 0 log, 1 don't log */
 	long offset; /* set it to MAX_ENTRY_NUM/2 for a bipolar scale */
-	unsigned long min_lat;
-	unsigned long max_lat;
+	long min_lat;
+	long max_lat;
 	unsigned long long below_hist_bound_samples;
 	unsigned long long above_hist_bound_samples;
-	unsigned long long accumulate_lat;
+	long long accumulate_lat;
 	unsigned long long total_samples;
 	unsigned long long hist_array[MAX_ENTRY_NUM];
 };
@@ -152,8 +154,8 @@ static struct enable_data timerandwakeup_enabled_data = {
 static DEFINE_PER_CPU(struct maxlatproc_data, timerandwakeup_maxlatproc);
 #endif
 
-void notrace latency_hist(int latency_type, int cpu, unsigned long latency,
-			  unsigned long timeroffset, cycle_t stop,
+void notrace latency_hist(int latency_type, int cpu, long latency,
+			  long timeroffset, cycle_t stop,
 			  struct task_struct *p)
 {
 	struct hist_data *my_hist;
@@ -224,7 +226,7 @@ void notrace latency_hist(int latency_type, int cpu, unsigned long latency,
 		my_hist->hist_array[latency]++;
 
 	if (unlikely(latency > my_hist->max_lat ||
-	    my_hist->min_lat == ULONG_MAX)) {
+	    my_hist->min_lat == LONG_MAX)) {
 #if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
     defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
 		if (latency_type == WAKEUP_LATENCY ||
@@ -263,15 +265,14 @@ static void *l_start(struct seq_file *m, loff_t *pos)
 		atomic_dec(&my_hist->hist_mode);
 
 		if (likely(my_hist->total_samples)) {
-			unsigned long avg = (unsigned long)
-			    div64_u64(my_hist->accumulate_lat,
+			long avg = (long) div64_s64(my_hist->accumulate_lat,
 			    my_hist->total_samples);
 			snprintf(minstr, sizeof(minstr), "%ld",
-			    (long) my_hist->min_lat - my_hist->offset);
+			    my_hist->min_lat - my_hist->offset);
 			snprintf(avgstr, sizeof(avgstr), "%ld",
-			    (long) avg - my_hist->offset);
+			    avg - my_hist->offset);
 			snprintf(maxstr, sizeof(maxstr), "%ld",
-			    (long) my_hist->max_lat - my_hist->offset);
+			    my_hist->max_lat - my_hist->offset);
 		} else {
 			strcpy(minstr, "<undef>");
 			strcpy(avgstr, minstr);
@@ -376,10 +377,10 @@ static void hist_reset(struct hist_data *hist)
 	memset(hist->hist_array, 0, sizeof(hist->hist_array));
 	hist->below_hist_bound_samples = 0ULL;
 	hist->above_hist_bound_samples = 0ULL;
-	hist->min_lat = ULONG_MAX;
-	hist->max_lat = 0UL;
+	hist->min_lat = LONG_MAX;
+	hist->max_lat = LONG_MIN;
 	hist->total_samples = 0ULL;
-	hist->accumulate_lat = 0ULL;
+	hist->accumulate_lat = 0LL;
 
 	atomic_inc(&hist->hist_mode);
 }
@@ -790,9 +791,9 @@ static notrace void probe_preemptirqsoff_hist(void *v, int reason,
 
 			stop = ftrace_now(cpu);
 			time_set++;
-			if (start && stop >= start) {
-				unsigned long latency =
-				    nsecs_to_usecs(stop - start);
+			if (start) {
+				long latency = ((long) (stop - start)) /
+				    NSECS_PER_USECS;
 
 				latency_hist(IRQSOFF_LATENCY, cpu, latency, 0,
 				    stop, NULL);
@@ -808,9 +809,9 @@ static notrace void probe_preemptirqsoff_hist(void *v, int reason,
 
 			if (!(time_set++))
 				stop = ftrace_now(cpu);
-			if (start && stop >= start) {
-				unsigned long latency =
-				    nsecs_to_usecs(stop - start);
+			if (start) {
+				long latency = ((long) (stop - start)) /
+				    NSECS_PER_USECS;
 
 				latency_hist(PREEMPTOFF_LATENCY, cpu, latency,
 				    0, stop, NULL);
@@ -827,9 +828,10 @@ static notrace void probe_preemptirqsoff_hist(void *v, int reason,
 
 			if (!time_set)
 				stop = ftrace_now(cpu);
-			if (start && stop >= start) {
-				unsigned long latency =
-				    nsecs_to_usecs(stop - start);
+			if (start) {
+				long latency = ((long) (stop - start)) /
+				    NSECS_PER_USECS;
+
 				latency_hist(PREEMPTIRQSOFF_LATENCY, cpu,
 				    latency, 0, stop, NULL);
 			}
@@ -908,7 +910,7 @@ static notrace void probe_wakeup_latency_hist_stop(void *v,
 {
 	unsigned long flags;
 	int cpu = task_cpu(next);
-	unsigned long latency;
+	long latency;
 	cycle_t stop;
 	struct task_struct *cpu_wakeup_task;
 
@@ -933,13 +935,17 @@ static notrace void probe_wakeup_latency_hist_stop(void *v,
 		goto out;
 	}
 
+	if (current->prio == cpu_wakeup_task->prio)
+		per_cpu(wakeup_sharedprio, cpu) = 1;
+
 	/*
 	 * The task we are waiting for is about to be switched to.
 	 * Calculate latency and store it in histogram.
 	 */
 	stop = ftrace_now(raw_smp_processor_id());
 
-	latency = nsecs_to_usecs(stop - next->preempt_timestamp_hist);
+	latency = ((long) (stop - next->preempt_timestamp_hist)) /
+	    NSECS_PER_USECS;
 
 	if (per_cpu(wakeup_sharedprio, cpu)) {
 		latency_hist(WAKEUP_LATENCY_SHAREDPRIO, cpu, latency, 0, stop,
@@ -975,7 +981,7 @@ static notrace void probe_hrtimer_interrupt(void *v, int cpu,
 	    (task->prio < curr->prio ||
 	    (task->prio == curr->prio &&
 	    !cpumask_test_cpu(cpu, &task->cpus_allowed)))) {
-		unsigned long latency;
+		long latency;
 		cycle_t now;
 
 		if (missed_timer_offsets_pid) {
@@ -985,7 +991,7 @@ static notrace void probe_hrtimer_interrupt(void *v, int cpu,
 		}
 
 		now = ftrace_now(cpu);
-		latency = (unsigned long) div_s64(-latency_ns, 1000);
+		latency = (long) div_s64(-latency_ns, NSECS_PER_USECS);
 		latency_hist(MISSED_TIMER_OFFSETS, cpu, latency, latency, now,
 		    task);
 #ifdef CONFIG_WAKEUP_LATENCY_HIST
@@ -1026,7 +1032,7 @@ static __init int latency_hist_init(void)
 		    &per_cpu(irqsoff_hist, i), &latency_hist_fops);
 		my_hist = &per_cpu(irqsoff_hist, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 	}
 	entry = debugfs_create_file("reset", 0644, dentry,
 	    (void *)IRQSOFF_LATENCY, &latency_hist_reset_fops);
@@ -1041,7 +1047,7 @@ static __init int latency_hist_init(void)
 		    &per_cpu(preemptoff_hist, i), &latency_hist_fops);
 		my_hist = &per_cpu(preemptoff_hist, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 	}
 	entry = debugfs_create_file("reset", 0644, dentry,
 	    (void *)PREEMPTOFF_LATENCY, &latency_hist_reset_fops);
@@ -1056,7 +1062,7 @@ static __init int latency_hist_init(void)
 		    &per_cpu(preemptirqsoff_hist, i), &latency_hist_fops);
 		my_hist = &per_cpu(preemptirqsoff_hist, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 	}
 	entry = debugfs_create_file("reset", 0644, dentry,
 	    (void *)PREEMPTIRQSOFF_LATENCY, &latency_hist_reset_fops);
@@ -1081,14 +1087,14 @@ static __init int latency_hist_init(void)
 		    &latency_hist_fops);
 		my_hist = &per_cpu(wakeup_latency_hist, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 
 		entry = debugfs_create_file(name, 0444, dentry_sharedprio,
 		    &per_cpu(wakeup_latency_hist_sharedprio, i),
 		    &latency_hist_fops);
 		my_hist = &per_cpu(wakeup_latency_hist_sharedprio, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 
 		sprintf(name, cpufmt_maxlatproc, i);
 
@@ -1122,7 +1128,7 @@ static __init int latency_hist_init(void)
 		    &per_cpu(missed_timer_offsets, i), &latency_hist_fops);
 		my_hist = &per_cpu(missed_timer_offsets, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 
 		sprintf(name, cpufmt_maxlatproc, i);
 		mp = &per_cpu(missed_timer_offsets_maxlatproc, i);
@@ -1150,7 +1156,7 @@ static __init int latency_hist_init(void)
 		    &latency_hist_fops);
 		my_hist = &per_cpu(timerandwakeup_latency_hist, i);
 		atomic_set(&my_hist->hist_mode, 1);
-		my_hist->min_lat = 0xFFFFFFFFUL;
+		my_hist->min_lat = LONG_MAX;
 
 		sprintf(name, cpufmt_maxlatproc, i);
 		mp = &per_cpu(timerandwakeup_maxlatproc, i);
diff --git a/localversion-rt b/localversion-rt
index 21988f9..366440d 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt34
+-rt35
diff --git a/mm/slab.c b/mm/slab.c
index 5f0c5ef..3bef5e5 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -739,8 +739,26 @@ slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg)
 {
 	unsigned int i;
 
+	get_cpu_light();
 	for_each_online_cpu(i)
 		func(arg, i);
+	put_cpu_light();
+}
+
+static void lock_slab_on(unsigned int cpu)
+{
+	if (cpu == smp_processor_id())
+		local_lock_irq(slab_lock);
+	else
+		local_spin_lock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock);
+}
+
+static void unlock_slab_on(unsigned int cpu)
+{
+	if (cpu == smp_processor_id())
+		local_unlock_irq(slab_lock);
+	else
+		local_spin_unlock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock);
 }
 #endif
 
@@ -2627,10 +2645,10 @@ static void do_drain(void *arg, int cpu)
 {
 	LIST_HEAD(tmp);
 
-	spin_lock_irq(&per_cpu(slab_lock, cpu).lock);
+	lock_slab_on(cpu);
 	__do_drain(arg, cpu);
 	list_splice_init(&per_cpu(slab_free_list, cpu), &tmp);
-	spin_unlock_irq(&per_cpu(slab_lock, cpu).lock);
+	unlock_slab_on(cpu);
 	free_delayed(&tmp);
 }
 #endif
@@ -4095,9 +4113,9 @@ static void do_ccupdate_local(void *info)
 #else
 static void do_ccupdate_local(void *info, int cpu)
 {
-	spin_lock_irq(&per_cpu(slab_lock, cpu).lock);
+	lock_slab_on(cpu);
 	__do_ccupdate_local(info, cpu);
-	spin_unlock_irq(&per_cpu(slab_lock, cpu).lock);
+	unlock_slab_on(cpu);
 }
 #endif
 
