hrtimer: Iterate only over active clock-bases

index bee0c1f78091..3152f327c988 100644
@@ -879,6 +879,9 @@ static void __remove_hrtimer(struct hrtimer *timer,
 
 	next_timer = timerqueue_getnext(&base->active);
 	timerqueue_del(&base->active, &timer->node);
+	if (!timerqueue_getnext(&base->active))
+		base->cpu_base->active_bases &= ~(1 << base->index);
+
 	if (&timer->node == next_timer) {
 #ifdef CONFIG_HIGH_RES_TIMERS
 		/* Reprogram the clock event device. if enabled */

@@ -892,8 +895,6 @@ static void __remove_hrtimer(struct hrtimer *timer,
 		}
 #endif
 	}
-	if (!timerqueue_getnext(&base->active))
-		base->cpu_base->active_bases &= ~(1 << base->index);
 out:
 	timer->state = newstate;
 }

index 3152f327c988..9da63e9ee63b 100644
@@ -110,6 +110,31 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id)
 }
 
 
+static inline int __next_bit(unsigned int active_bases, int bit)
+{
+	do {
+		if (active_bases & (1 << bit))
+			return bit;
+	} while (++bit < HRTIMER_MAX_CLOCK_BASES);
+
+	/* We should never reach here */
+	return 0;
+}
+
+/*
+ * for_each_active_base: iterate over all active clock bases
+ * @_bit: 'int' variable for internal purpose
+ * @_base: holds pointer to a active clock base
+ * @_cpu_base: cpu base to iterate on
+ * @_active_bases: 'unsigned int' variable for internal purpose
+ */
+#define for_each_active_base(_bit, _base, _cpu_base, _active_bases)	\
+	for ((_active_bases) = (_cpu_base)->active_bases, (_bit) = -1;	\
+		(_active_bases) &&					\
+		((_bit) = __next_bit(_active_bases, ++_bit),		\
+		(_base) = (_cpu_base)->clock_base + _bit);		\
+		(_active_bases) &= ~(1 << (_bit)))
+
 /*
  * Get the coarse grained time at the softirq based on xtime and
  * wall_to_monotonic.

@@ -443,19 +468,15 @@ static inline void debug_deactivate(struct hrtimer *timer)
 #if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
 static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base)
 {
-	struct hrtimer_clock_base *base = cpu_base->clock_base;
+	struct hrtimer_clock_base *base;
 	ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
+	struct hrtimer *timer;
+	unsigned int active_bases;
 	int i;
 
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
-		struct timerqueue_node *next;
-		struct hrtimer *timer;
-
-		next = timerqueue_getnext(&base->active);
-		if (!next)
-			continue;
-
-		timer = container_of(next, struct hrtimer, node);
+	for_each_active_base(i, base, cpu_base, active_bases) {
+		timer = container_of(timerqueue_getnext(&base->active),
+				     struct hrtimer, node);
 		expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 		if (expires.tv64 < expires_next.tv64)
 			expires_next = expires;

@@ -1245,6 +1266,8 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 {
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t expires_next, now, entry_time, delta;
+	struct hrtimer_clock_base *base;
+	unsigned int active_bases;
 	int i, retries = 0;
 
 	BUG_ON(!cpu_base->hres_active);

@@ -1264,15 +1287,10 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 	 */
 	cpu_base->expires_next.tv64 = KTIME_MAX;
 
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-		struct hrtimer_clock_base *base;
+	for_each_active_base(i, base, cpu_base, active_bases) {
 		struct timerqueue_node *node;
 		ktime_t basenow;
 
-		if (!(cpu_base->active_bases & (1 << i)))
-			continue;
-
-		base = cpu_base->clock_base + i;
 		basenow = ktime_add(now, base->offset);
 
 		while ((node = timerqueue_getnext(&base->active))) {

@@ -1435,16 +1453,13 @@ void hrtimer_run_queues(void)
 	struct timerqueue_node *node;
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base;
+	unsigned int active_bases;
 	int index, gettime = 1;
 
 	if (hrtimer_hres_active())
 		return;
 
-	for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
-		base = &cpu_base->clock_base[index];
-		if (!timerqueue_getnext(&base->active))
-			continue;
-
+	for_each_active_base(index, base, cpu_base, active_bases) {
 		if (gettime) {
 			hrtimer_get_softirq_time(cpu_base);
 			gettime = 0;

@@ -1665,6 +1680,8 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
 static void migrate_hrtimers(int scpu)
 {
 	struct hrtimer_cpu_base *old_base, *new_base;
+	struct hrtimer_clock_base *clock_base;
+	unsigned int active_bases;
 	int i;
 
 	BUG_ON(cpu_online(scpu));

@@ -1680,9 +1697,9 @@ static void migrate_hrtimers(int scpu)
 	raw_spin_lock(&new_base->lock);
 	raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
 
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-		migrate_hrtimer_list(&old_base->clock_base[i],
-				     &new_base->clock_base[i]);
+	for_each_active_base(i, clock_base, old_base, active_bases) {
+		migrate_hrtimer_list(clock_base,
+				     &new_base->clock_base[clock_base->index]);
 	}
 
 	raw_spin_unlock(&old_base->lock);

Index: linux/kernel/time/hrtimer.c
===================================================================
@@ -451,6 +451,9 @@ static ktime_t __hrtimer_get_next_event(
 		struct timerqueue_node *next;
 		struct hrtimer *timer;
 
+		if (!(cpu_base->active_bases & (1 << i)))
+			continue;
+
 		next = timerqueue_getnext(&base->active);
 		if (!next)
 			continue;

@@ -1441,6 +1444,9 @@ void hrtimer_run_queues(void)
 		return;
 
 	for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
+		if (!(cpu_base->active_bases & (1 << index)))
+			continue;
+
 		base = &cpu_base->clock_base[index];
 		if (!timerqueue_getnext(&base->active))
 			continue;

@@ -1681,6 +1687,8 @@ static void migrate_hrtimers(int scpu)
 	raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
+		if (!(old_base->active_bases & (1 << i)))
+			continue;
 		migrate_hrtimer_list(&old_base->clock_base[i],
 				     &new_base->clock_base[i]);
 	}

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -1660,29 +1660,35 @@ static void migrate_hrtimer_list(struct
 
 static void migrate_hrtimers(int scpu)
 {
-	struct hrtimer_cpu_base *old_base, *new_base;
+	struct hrtimer_cpu_base *old_cpu_base, *new_cpu_base;
 	int i;
 
 	BUG_ON(cpu_online(scpu));
 	tick_cancel_sched_timer(scpu);
 
 	local_irq_disable();
-	old_base = &per_cpu(hrtimer_bases, scpu);
-	new_base = this_cpu_ptr(&hrtimer_bases);
+	old_cpu_base = &per_cpu(hrtimer_bases, scpu);
+	new_cpu_base = this_cpu_ptr(&hrtimer_bases);
 	/*
 	 * The caller is globally serialized and nobody else
 	 * takes two locks at once, deadlock is not possible.
 	 */
-	raw_spin_lock(&new_base->lock);
-	raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
+	raw_spin_lock(&new_cpu_base->lock);
+	raw_spin_lock_nested(&old_cpu_base->lock, SINGLE_DEPTH_NESTING);
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-		migrate_hrtimer_list(&old_base->clock_base[i],
-				     &new_base->clock_base[i]);
+		struct hrtimer_clock_base *old_base = old_cpu_base->clock_base + i;
+		struct hrtimer_clock_base *new_base;
+
+		if (!old_base->active.next)
+			continue;
+
+		new_base = new_cpu_base->clock_base + i;
+		migrate_hrtimer_list(old_base, new_base);
 	}
 
-	raw_spin_unlock(&old_base->lock);
-	raw_spin_unlock(&new_base->lock);
+	raw_spin_unlock(&old_cpu_base->lock);
+	raw_spin_unlock(&new_cpu_base->lock);
 
 	/* Check, if we got expired work to do */
 	__hrtimer_peek_ahead_timers();

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -451,7 +451,7 @@ static ktime_t __hrtimer_get_next_event(
 		struct timerqueue_node *next;
 		struct hrtimer *timer;
 
-		next = timerqueue_getnext(&base->active);
+		next = base->active.next;
 		if (!next)
 			continue;
 

@@ -876,7 +876,7 @@ static void __remove_hrtimer(struct hrti
 	if (!(timer->state & HRTIMER_STATE_ENQUEUED))
 		goto out;
 
-	next_timer = timerqueue_getnext(&base->active);
+	next_timer = base->active.next;
 	timerqueue_del(&base->active, &timer->node);
 	if (&timer->node == next_timer) {
 #ifdef CONFIG_HIGH_RES_TIMERS

@@ -1271,7 +1271,7 @@ retry:
 
 		basenow = ktime_add(now, base->offset);
 
-		while ((node = timerqueue_getnext(&base->active))) {
+		while ((node = base->active.next)) {
 			struct hrtimer *timer;
 
 			timer = container_of(node, struct hrtimer, node);

@@ -1438,7 +1438,7 @@ void hrtimer_run_queues(void)
 
 	for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
 		base = &cpu_base->clock_base[index];
-		if (!timerqueue_getnext(&base->active))
+		if (!base->active.next)
 			continue;
 
 		if (gettime) {

@@ -1448,7 +1448,7 @@ void hrtimer_run_queues(void)
 
 		raw_spin_lock(&cpu_base->lock);
 
-		while ((node = timerqueue_getnext(&base->active))) {
+		while ((node = base->active.next)) {
 			struct hrtimer *timer;
 
 			timer = container_of(node, struct hrtimer, node);

@@ -1631,7 +1631,7 @@ static void migrate_hrtimer_list(struct
 	struct hrtimer *timer;
 	struct timerqueue_node *node;
 
-	while ((node = timerqueue_getnext(&old_base->active))) {
+	while ((node = old_base->active.next)) {
 		timer = container_of(node, struct hrtimer, node);
 		BUG_ON(hrtimer_callback_running(timer));
 		debug_deactivate(timer);

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -448,14 +448,14 @@ static ktime_t __hrtimer_get_next_event(
 	int i;
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
-		struct timerqueue_node *next;
+		struct timerqueue_node *node_next;
 		struct hrtimer *timer;
 
-		next = base->active.next;
-		if (!next)
+		node_next = base->active.next;
+		if (!node_next)
 			continue;
 
-		timer = container_of(next, struct hrtimer, node);
+		timer = container_of(node_next, struct hrtimer, node);
 		expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 		if (expires.tv64 < expires_next.tv64)
 			expires_next = expires;

@@ -872,13 +872,13 @@ static void __remove_hrtimer(struct hrti
 			     struct hrtimer_clock_base *base,
 			     unsigned long newstate, int reprogram)
 {
-	struct timerqueue_node *next_timer;
+	struct timerqueue_node *node_next;
 	if (!(timer->state & HRTIMER_STATE_ENQUEUED))
 		goto out;
 
-	next_timer = base->active.next;
+	node_next = base->active.next;
 	timerqueue_del(&base->active, &timer->node);
-	if (&timer->node == next_timer) {
+	if (&timer->node == node_next) {
 #ifdef CONFIG_HIGH_RES_TIMERS
 		/* Reprogram the clock event device. if enabled */
 		if (reprogram && hrtimer_hres_active()) {

@@ -1262,7 +1262,7 @@ retry:
 
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
 		struct hrtimer_clock_base *base;
-		struct timerqueue_node *node;
+		struct timerqueue_node *node_next;
 		ktime_t basenow;
 
 		base = cpu_base->clock_base + i;

@@ -1271,10 +1271,10 @@ retry:
 
 		basenow = ktime_add(now, base->offset);
 
-		while ((node = base->active.next)) {
+		while ((node_next = base->active.next)) {
 			struct hrtimer *timer;
 
-			timer = container_of(node, struct hrtimer, node);
+			timer = container_of(node_next, struct hrtimer, node);
 
 			/*
 			 * The immediate goal for using the softexpires is

@@ -1428,7 +1428,7 @@ void hrtimer_run_pending(void)
  */
 void hrtimer_run_queues(void)
 {
-	struct timerqueue_node *node;
+	struct timerqueue_node *node_next;
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base;
 	int index, gettime = 1;

@@ -1448,10 +1448,10 @@ void hrtimer_run_queues(void)
 
 		raw_spin_lock(&cpu_base->lock);
 
-		while ((node = base->active.next)) {
+		while ((node_next = base->active.next)) {
 			struct hrtimer *timer;
 
-			timer = container_of(node, struct hrtimer, node);
+			timer = container_of(node_next, struct hrtimer, node);
 			if (base->softirq_time.tv64 <=
 					hrtimer_get_expires_tv64(timer))
 				break;

@@ -1629,10 +1629,10 @@ static void migrate_hrtimer_list(struct
 				struct hrtimer_clock_base *new_base)
 {
 	struct hrtimer *timer;
-	struct timerqueue_node *node;
+	struct timerqueue_node *node_next;
 
-	while ((node = old_base->active.next)) {
-		timer = container_of(node, struct hrtimer, node);
+	while ((node_next = old_base->active.next)) {
+		timer = container_of(node_next, struct hrtimer, node);
 		BUG_ON(hrtimer_callback_running(timer));
 		debug_deactivate(timer);
 

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -879,6 +879,9 @@ static void __remove_hrtimer(struct hrti
 
 	next_timer = timerqueue_getnext(&base->active);
 	timerqueue_del(&base->active, &timer->node);
+	if (!timerqueue_getnext(&base->active))
+		base->cpu_base->active_bases &= ~(1 << base->index);
+
 	if (&timer->node == next_timer) {
 #ifdef CONFIG_HIGH_RES_TIMERS
 		/* Reprogram the clock event device. if enabled */

@@ -892,8 +895,6 @@ static void __remove_hrtimer(struct hrti
 		}
 #endif
 	}
-	if (!timerqueue_getnext(&base->active))
-		base->cpu_base->active_bases &= ~(1 << base->index);
 out:
 	timer->state = newstate;
 }

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -137,7 +137,6 @@ struct hrtimer_sleeper {
  *			timer to a base on another cpu.
  * @clockid:		clock id for per_cpu support
  * @active:		red black tree root node for the active timers
- * @resolution:		the resolution of the clock, in nanoseconds
  * @get_time:		function to retrieve the current time of the clock
  * @softirq_time:	the time when running the hrtimer queue in the softirq
  * @offset:		offset of this clock to the monotonic base

@@ -147,7 +146,6 @@ struct hrtimer_clock_base {
 	int			index;
 	clockid_t		clockid;
 	struct timerqueue_head	active;
-	ktime_t			resolution;
 	ktime_t			(*get_time)(void);
 	ktime_t			softirq_time;
 	ktime_t			offset;

@@ -295,11 +293,15 @@ extern void hrtimer_peek_ahead_timers(vo
 
 extern void clock_was_set_delayed(void);
 
+extern unsigned int hrtimer_resolution;
+
 #else
 
 # define MONOTONIC_RES_NSEC	LOW_RES_NSEC
 # define KTIME_MONOTONIC_RES	KTIME_LOW_RES
 
+#define hrtimer_resolution	LOW_RES_NSEC
+
 static inline void hrtimer_peek_ahead_timers(void) { }
 
 /*

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -66,7 +66,6 @@
  */
 DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
 {
-
 	.lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock),
 	.clock_base =
 	{

@@ -74,25 +73,21 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base,
 			.index = HRTIMER_BASE_MONOTONIC,
 			.clockid = CLOCK_MONOTONIC,
 			.get_time = &ktime_get,
-			.resolution = KTIME_LOW_RES,
 		},
 		{
 			.index = HRTIMER_BASE_REALTIME,
 			.clockid = CLOCK_REALTIME,
 			.get_time = &ktime_get_real,
-			.resolution = KTIME_LOW_RES,
 		},
 		{
 			.index = HRTIMER_BASE_BOOTTIME,
 			.clockid = CLOCK_BOOTTIME,
 			.get_time = &ktime_get_boottime,
-			.resolution = KTIME_LOW_RES,
 		},
 		{
 			.index = HRTIMER_BASE_TAI,
 			.clockid = CLOCK_TAI,
 			.get_time = &ktime_get_clocktai,
-			.resolution = KTIME_LOW_RES,
 		},
 	}
 };

@@ -478,6 +473,8 @@ static ktime_t __hrtimer_get_next_event(
  * High resolution timer enabled ?
  */
 static int hrtimer_hres_enabled __read_mostly  = 1;
+unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC;
+EXPORT_SYMBOL_GPL(hrtimer_resolution);
 
 /*
  * Enable / Disable high resolution mode

@@ -660,7 +657,7 @@ static void retrigger_next_event(void *a
  */
 static int hrtimer_switch_to_hres(void)
 {
-	int i, cpu = smp_processor_id();
+	int cpu = smp_processor_id();
 	struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
 	unsigned long flags;
 

@@ -676,8 +673,7 @@ static int hrtimer_switch_to_hres(void)
 		return 0;
 	}
 	base->hres_active = 1;
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
-		base->clock_base[i].resolution = KTIME_HIGH_RES;
+	hrtimer_resolution = HIGH_RES_NSEC;
 
 	tick_setup_sched_timer();
 	/* "Retrigger" the interrupt to get things going */

@@ -812,8 +808,8 @@ u64 hrtimer_forward(struct hrtimer *time
 	if (delta.tv64 < 0)
 		return 0;
 
-	if (interval.tv64 < timer->base->resolution.tv64)
-		interval.tv64 = timer->base->resolution.tv64;
+	if (interval.tv64 < hrtimer_resolution)
+		interval.tv64 = hrtimer_resolution;
 
 	if (unlikely(delta.tv64 >= interval.tv64)) {
 		s64 incr = ktime_to_ns(interval);

@@ -955,7 +951,7 @@ int __hrtimer_start_range_ns(struct hrti
 		 * timeouts. This will go away with the GTOD framework.
 		 */
 #ifdef CONFIG_TIME_LOW_RES
-		tim = ktime_add_safe(tim, base->resolution);
+		tim = ktime_add_safe(tim, ktime_set(0, hrtimer_resolution));
 #endif
 	}
 

@@ -1185,12 +1181,8 @@ EXPORT_SYMBOL_GPL(hrtimer_init);
  */
 int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 {
-	struct hrtimer_cpu_base *cpu_base;
-	int base = hrtimer_clockid_to_base(which_clock);
-
-	cpu_base = raw_cpu_ptr(&hrtimer_bases);
-	*tp = ktime_to_timespec(cpu_base->clock_base[base].resolution);
-
+	tp->tv_sec = 0;
+	tp->tv_nsec = hrtimer_resolution;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_res);

Index: tip/kernel/time/timer_list.c
===================================================================
@@ -120,10 +120,10 @@ static void
 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
 {
 	SEQ_printf(m, "  .base:       %pK\n", base);
-	SEQ_printf(m, "  .index:      %d\n",
-			base->index);
-	SEQ_printf(m, "  .resolution: %Lu nsecs\n",
-			(unsigned long long)ktime_to_ns(base->resolution));
+	SEQ_printf(m, "  .index:      %d\n", base->index);
+
+	SEQ_printf(m, "  .resolution: %u nsecs\n", (unsigned) hrtimer_resolution);
+
 	SEQ_printf(m,   "  .get_time:   ");
 	print_name_offset(m, base->get_time);
 	SEQ_printf(m,   "\n");

Index: tip/net/sched/sch_api.c
===================================================================
@@ -1879,13 +1879,10 @@ EXPORT_SYMBOL(tcf_destroy_chain);
 #ifdef CONFIG_PROC_FS
 static int psched_show(struct seq_file *seq, void *v)
 {
-	struct timespec ts;
-
-	hrtimer_get_res(CLOCK_MONOTONIC, &ts);
 	seq_printf(seq, "%08x %08x %08x %08x\n",
 		   (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1),
 		   1000000,
-		   (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts)));
+		   (u32)NSEC_PER_SEC / hrtimer_resolution);
 
 	return 0;
 }

Index: tip/sound/core/hrtimer.c
===================================================================
@@ -121,16 +121,9 @@ static struct snd_timer *mytimer;
 static int __init snd_hrtimer_init(void)
 {
 	struct snd_timer *timer;
-	struct timespec tp;
 	int err;
 
-	hrtimer_get_res(CLOCK_MONOTONIC, &tp);
-	if (tp.tv_sec > 0 || !tp.tv_nsec) {
-		pr_err("snd-hrtimer: Invalid resolution %u.%09u",
-			   (unsigned)tp.tv_sec, (unsigned)tp.tv_nsec);
-		return -EINVAL;
-	}
-	resolution = tp.tv_nsec;
+	resolution = hrtimer_resolution;
 
 	/* Create a new timer and set up the fields */
 	err = snd_timer_global_new("hrtimer", SNDRV_TIMER_GLOBAL_HRTIMER,

Index: tip/sound/drivers/pcsp/pcsp.c
===================================================================
@@ -42,16 +42,13 @@ struct snd_pcsp pcsp_chip;
 static int snd_pcsp_create(struct snd_card *card)
 {
 	static struct snd_device_ops ops = { };
-	struct timespec tp;
-	int err;
-	int div, min_div, order;
-
-	hrtimer_get_res(CLOCK_MONOTONIC, &tp);
+	unsigned int resolution = hrtimer_resolution;
+	int err, div, min_div, order;
 
 	if (!nopcm) {
-		if (tp.tv_sec || tp.tv_nsec > PCSP_MAX_PERIOD_NS) {
+		if (resolution > PCSP_MAX_PERIOD_NS) {
 			printk(KERN_ERR "PCSP: Timer resolution is not sufficient "
-				"(%linS)\n", tp.tv_nsec);
+				"(%linS)\n", resolution);
 			printk(KERN_ERR "PCSP: Make sure you have HPET and ACPI "
 				"enabled.\n");
 			printk(KERN_ERR "PCSP: Turned into nopcm mode.\n");

@@ -59,13 +56,13 @@ static int snd_pcsp_create(struct snd_ca
 		}
 	}
 
-	if (loops_per_jiffy >= PCSP_MIN_LPJ && tp.tv_nsec <= PCSP_MIN_PERIOD_NS)
+	if (loops_per_jiffy >= PCSP_MIN_LPJ && resolution <= PCSP_MIN_PERIOD_NS)
 		min_div = MIN_DIV;
 	else
 		min_div = MAX_DIV;
 #if PCSP_DEBUG
 	printk(KERN_DEBUG "PCSP: lpj=%li, min_div=%i, res=%li\n",
-	       loops_per_jiffy, min_div, tp.tv_nsec);
+	       loops_per_jiffy, min_div, resolution);
 #endif
 
 	div = MAX_DIV / min_div;

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -385,7 +385,6 @@ static inline int hrtimer_restart(struct
 
 /* Query timers: */
 extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
-extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
 
 extern ktime_t hrtimer_get_next_event(void);
 

Index: tip/kernel/time/alarmtimer.c
===================================================================
@@ -495,12 +495,12 @@ static enum alarmtimer_restart alarm_han
  */
 static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
 {
-	clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid;
-
 	if (!alarmtimer_get_rtcdev())
 		return -EINVAL;
 
-	return hrtimer_get_res(baseid, tp);
+	tp->tv_sec = 0;
+	tp->tv_nsec = hrtimer_resolution;
+	return 0;
 }
 
 /**

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -1171,22 +1171,6 @@ void hrtimer_init(struct hrtimer *timer,
 }
 EXPORT_SYMBOL_GPL(hrtimer_init);
 
-/**
- * hrtimer_get_res - get the timer resolution for a clock
- * @which_clock: which clock to query
- * @tp:		 pointer to timespec variable to store the resolution
- *
- * Store the resolution of the clock selected by @which_clock in the
- * variable pointed to by @tp.
- */
-int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
-{
-	tp->tv_sec = 0;
-	tp->tv_nsec = hrtimer_resolution;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(hrtimer_get_res);
-
 static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
 {
 	struct hrtimer_clock_base *base = timer->base;

Index: tip/kernel/time/posix-timers.c
===================================================================
@@ -272,13 +272,20 @@ static int posix_get_tai(clockid_t which
 	return 0;
 }
 
+static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec *tp)
+{
+	tp->tv_sec = 0;
+	tp->tv_nsec = hrtimer_resolution;
+	return 0;
+}
+
 /*
  * Initialize everything, well, just everything in Posix clocks/timers ;)
  */
 static __init int init_posix_timers(void)
 {
 	struct k_clock clock_realtime = {
-		.clock_getres	= hrtimer_get_res,
+		.clock_getres	= posix_get_hrtimer_res,
 		.clock_get	= posix_clock_realtime_get,
 		.clock_set	= posix_clock_realtime_set,
 		.clock_adj	= posix_clock_realtime_adj,

@@ -290,7 +297,7 @@ static __init int init_posix_timers(void
 		.timer_del	= common_timer_del,
 	};
 	struct k_clock clock_monotonic = {
-		.clock_getres	= hrtimer_get_res,
+		.clock_getres	= posix_get_hrtimer_res,
 		.clock_get	= posix_ktime_get_ts,
 		.nsleep		= common_nsleep,
 		.nsleep_restart	= hrtimer_nanosleep_restart,

@@ -300,7 +307,7 @@ static __init int init_posix_timers(void
 		.timer_del	= common_timer_del,
 	};
 	struct k_clock clock_monotonic_raw = {
-		.clock_getres	= hrtimer_get_res,
+		.clock_getres	= posix_get_hrtimer_res,
 		.clock_get	= posix_get_monotonic_raw,
 	};
 	struct k_clock clock_realtime_coarse = {

@@ -312,7 +319,7 @@ static __init int init_posix_timers(void
 		.clock_get	= posix_get_monotonic_coarse,
 	};
 	struct k_clock clock_tai = {
-		.clock_getres	= hrtimer_get_res,
+		.clock_getres	= posix_get_hrtimer_res,
 		.clock_get	= posix_get_tai,
 		.nsleep		= common_nsleep,
 		.nsleep_restart	= hrtimer_nanosleep_restart,

@@ -322,7 +329,7 @@ static __init int init_posix_timers(void
 		.timer_del	= common_timer_del,
 	};
 	struct k_clock clock_boottime = {
-		.clock_getres	= hrtimer_get_res,
+		.clock_getres	= posix_get_hrtimer_res,
 		.clock_get	= posix_get_boottime,
 		.nsleep		= common_nsleep,
 		.nsleep_restart	= hrtimer_nanosleep_restart,

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -187,10 +187,10 @@ struct hrtimer_cpu_base {
 	int				in_hrtirq;
 	int				hres_active;
 	int				hang_detected;
-	unsigned long			nr_events;
-	unsigned long			nr_retries;
-	unsigned long			nr_hangs;
-	ktime_t				max_hang_time;
+	unsigned int			nr_events;
+	unsigned int			nr_retries;
+	unsigned int			nr_hangs;
+	unsigned int			max_hang_time;
 #endif
 	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
 };

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -1319,8 +1319,8 @@ retry:
 	cpu_base->hang_detected = 1;
 	raw_spin_unlock(&cpu_base->lock);
 	delta = ktime_sub(now, entry_time);
-	if (delta.tv64 > cpu_base->max_hang_time.tv64)
-		cpu_base->max_hang_time = delta;
+	if ((unsigned int)delta.tv64 > cpu_base->max_hang_time)
+		cpu_base->max_hang_time = (unsigned int) delta.tv64;
 	/*
 	 * Limit it to a sensible value as we enforce a longer
 	 * delay. Give the CPU at least 100ms to catch up.

Index: tip/kernel/time/timer_list.c
===================================================================
@@ -158,7 +158,7 @@ static void print_cpu(struct seq_file *m
 	P(nr_events);
 	P(nr_retries);
 	P(nr_hangs);
-	P_ns(max_hang_time);
+	P(max_hang_time);
 #endif
 #undef P
 #undef P_ns

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -138,7 +138,6 @@ struct hrtimer_sleeper {
  * @clockid:		clock id for per_cpu support
  * @active:		red black tree root node for the active timers
  * @get_time:		function to retrieve the current time of the clock
- * @softirq_time:	the time when running the hrtimer queue in the softirq
  * @offset:		offset of this clock to the monotonic base
  */
 struct hrtimer_clock_base {

@@ -147,7 +146,6 @@ struct hrtimer_clock_base {
 	clockid_t		clockid;
 	struct timerqueue_head	active;
 	ktime_t			(*get_time)(void);
-	ktime_t			softirq_time;
 	ktime_t			offset;
 };
 

@@ -260,19 +258,16 @@ static inline ktime_t hrtimer_expires_re
 	return ktime_sub(timer->node.expires, timer->base->get_time());
 }
 
-#ifdef CONFIG_HIGH_RES_TIMERS
-struct clock_event_device;
-
-extern void hrtimer_interrupt(struct clock_event_device *dev);
-
-/*
- * In high resolution mode the time reference must be read accurate
- */
 static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
 {
 	return timer->base->get_time();
 }
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+struct clock_event_device;
+
+extern void hrtimer_interrupt(struct clock_event_device *dev);
+
 static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 {
 	return timer->base->cpu_base->hres_active;

@@ -304,15 +299,6 @@ extern unsigned int hrtimer_resolution;
 
 static inline void hrtimer_peek_ahead_timers(void) { }
 
-/*
- * In non high resolution mode the time reference is taken from
- * the base softirq time variable.
- */
-static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
-{
-	return timer->base->softirq_time;
-}
-
 static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 {
 	return 0;

205 lines not on this page · raw message

Index: tip/kernel/time/timekeeping.c
===================================================================
@@ -1926,37 +1926,6 @@ void do_timer(unsigned long ticks)
 }
 
 /**
- * ktime_get_update_offsets_tick - hrtimer helper
- * @offs_real:	pointer to storage for monotonic -> realtime offset
- * @offs_boot:	pointer to storage for monotonic -> boottime offset
- * @offs_tai:	pointer to storage for monotonic -> clock tai offset
- *
- * Returns monotonic time at last tick and various offsets
- */
-ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real, ktime_t *offs_boot,
-							ktime_t *offs_tai)
-{
-	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned int seq;
-	ktime_t base;
-	u64 nsecs;
-
-	do {
-		seq = read_seqcount_begin(&tk_core.seq);
-
-		base = tk->tkr_mono.base;
-		nsecs = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
-
-		*offs_real = tk->offs_real;
-		*offs_boot = tk->offs_boot;
-		*offs_tai = tk->offs_tai;
-	} while (read_seqcount_retry(&tk_core.seq, seq));
-
-	return ktime_add_ns(base, nsecs);
-}
-
-#ifdef CONFIG_HIGH_RES_TIMERS
-/**
  * ktime_get_update_offsets_now - hrtimer helper
  * @offs_real:	pointer to storage for monotonic -> realtime offset
  * @offs_boot:	pointer to storage for monotonic -> boottime offset

@@ -1986,7 +1955,6 @@ ktime_t ktime_get_update_offsets_now(kti
 
 	return ktime_add_ns(base, nsecs);
 }
-#endif
 
 /**
  * do_adjtimex() - Accessor function to NTP __do_adjtimex function

Index: tip/kernel/time/timekeeping.h
===================================================================
@@ -3,9 +3,6 @@
 /*
  * Internal interfaces for kernel/time/
  */
-extern ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real,
-						ktime_t *offs_boot,
-						ktime_t *offs_tai);
 extern ktime_t ktime_get_update_offsets_now(ktime_t *offs_real,
 						ktime_t *offs_boot,
 						ktime_t *offs_tai);

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -163,7 +163,7 @@ enum  hrtimer_base_type {
  *			and timers
  * @cpu:		cpu number
  * @active_bases:	Bitfield to mark bases with active timers
- * @clock_was_set:	Indicates that clock was set from irq context.
+ * @clock_was_set_seq:	Sequence counter of clock was set events
  * @expires_next:	absolute time of the next event which was scheduled
  *			via clock_set_next_event()
  * @in_hrtirq:		hrtimer_interrupt() is currently executing

@@ -179,7 +179,7 @@ struct hrtimer_cpu_base {
 	raw_spinlock_t			lock;
 	unsigned int			cpu;
 	unsigned int			active_bases;
-	unsigned int			clock_was_set;
+	unsigned int			clock_was_set_seq;
 #ifdef CONFIG_HIGH_RES_TIMERS
 	ktime_t				expires_next;
 	int				in_hrtirq;

Index: tip/include/linux/timekeeper_internal.h
===================================================================
@@ -49,6 +49,7 @@ struct tk_read_base {
  * @offs_boot:		Offset clock monotonic -> clock boottime
  * @offs_tai:		Offset clock monotonic -> clock tai
  * @tai_offset:		The current UTC to TAI offset in seconds
+ * @clock_was_set_seq:	The sequence number of clock was set events
  * @raw_time:		Monotonic raw base time in timespec64 format
  * @cycle_interval:	Number of clock cycles in one NTP interval
  * @xtime_interval:	Number of clock shifted nano seconds in one NTP

@@ -85,6 +86,7 @@ struct timekeeper {
 	ktime_t			offs_boot;
 	ktime_t			offs_tai;
 	s32			tai_offset;
+	unsigned int		clock_was_set_seq;
 	struct timespec64	raw_time;
 
 	/* The following members are for timekeeping internal use */

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -451,7 +451,8 @@ static inline ktime_t hrtimer_update_bas
 	ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset;
 	ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset;
 
-	return ktime_get_update_offsets_now(offs_real, offs_boot, offs_tai);
+	return ktime_get_update_offsets_now(&base->clock_was_set_seq,
+					    offs_real, offs_boot, offs_tai);
 }
 
 /* High resolution timer related functions */

Index: tip/kernel/time/timekeeping.c
===================================================================
@@ -602,6 +602,9 @@ static void timekeeping_update(struct ti
 
 	update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono);
 	update_fast_timekeeper(&tk->tkr_raw,  &tk_fast_raw);
+
+	if (action & TK_CLOCK_WAS_SET)
+		tk->clock_was_set_seq++;
 }
 
 /**

@@ -1927,15 +1930,19 @@ void do_timer(unsigned long ticks)
 
 /**
  * ktime_get_update_offsets_now - hrtimer helper
+ * @cwsseq:	pointer to check and store the clock was set sequence number
  * @offs_real:	pointer to storage for monotonic -> realtime offset
  * @offs_boot:	pointer to storage for monotonic -> boottime offset
  * @offs_tai:	pointer to storage for monotonic -> clock tai offset
  *
- * Returns current monotonic time and updates the offsets
+ * Returns current monotonic time and updates the offsets if the
+ * sequence number in @cwsseq and timekeeper.clock_was_set_seq are
+ * different.
+ *
  * Called from hrtimer_interrupt() or retrigger_next_event()
  */
-ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot,
-							ktime_t *offs_tai)
+ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
+				     ktime_t *offs_boot, ktime_t *offs_tai)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned int seq;

@@ -1947,10 +1954,12 @@ ktime_t ktime_get_update_offsets_now(kti
 
 		base = tk->tkr_mono.base;
 		nsecs = timekeeping_get_ns(&tk->tkr_mono);
-
-		*offs_real = tk->offs_real;
-		*offs_boot = tk->offs_boot;
-		*offs_tai = tk->offs_tai;
+		if (*cwsseq != tk->clock_was_set_seq) {
+			*cwsseq = tk->clock_was_set_seq;
+			*offs_real = tk->offs_real;
+			*offs_boot = tk->offs_boot;
+			*offs_tai = tk->offs_tai;
+		}
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
 	return ktime_add_ns(base, nsecs);

Index: tip/kernel/time/timekeeping.h
===================================================================
@@ -3,9 +3,10 @@
 /*
  * Internal interfaces for kernel/time/
  */
-extern ktime_t ktime_get_update_offsets_now(ktime_t *offs_real,
-						ktime_t *offs_boot,
-						ktime_t *offs_tai);
+extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq,
+					    ktime_t *offs_real,
+					    ktime_t *offs_boot,
+					    ktime_t *offs_tai);
 
 extern int timekeeping_valid_for_hres(void);
 extern u64 timekeeping_max_deferment(void);

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -181,10 +181,10 @@ struct hrtimer_cpu_base {
 	unsigned int			active_bases;
 	unsigned int			clock_was_set_seq;
 #ifdef CONFIG_HIGH_RES_TIMERS
+	unsigned int			in_hrtirq	: 1,
+					hres_active	: 1,
+					hang_detected	: 1;
 	ktime_t				expires_next;
-	int				in_hrtirq;
-	int				hres_active;
-	int				hang_detected;
 	unsigned int			nr_events;
 	unsigned int			nr_retries;
 	unsigned int			nr_hangs;

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -492,9 +492,14 @@ static inline int hrtimer_is_hres_enable
 /*
  * Is the high resolution mode active ?
  */
+static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *cpu_base)
+{
+	return cpu_base->hres_active;
+}
+
 static inline int hrtimer_hres_active(void)
 {
-	return __this_cpu_read(hrtimer_bases.hres_active);
+	return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases));
 }
 
 /*

@@ -628,7 +633,7 @@ static void retrigger_next_event(void *a
 {
 	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
 
-	if (!hrtimer_hres_active())
+	if (!base->hres_active)
 		return;
 
 	raw_spin_lock(&base->lock);

@@ -685,6 +690,7 @@ void clock_was_set_delayed(void)
 
 #else
 
+static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *b) { return 0; }
 static inline int hrtimer_hres_active(void) { return 0; }
 static inline int hrtimer_is_hres_enabled(void) { return 0; }
 static inline int hrtimer_switch_to_hres(void) { return 0; }

@@ -854,25 +860,27 @@ static void __remove_hrtimer(struct hrti
 			     struct hrtimer_clock_base *base,
 			     unsigned long newstate, int reprogram)
 {
+	struct hrtimer_cpu_base *cpu_base = base->cpu_base;
 	struct timerqueue_node *next_timer;
+
 	if (!(timer->state & HRTIMER_STATE_ENQUEUED))
 		goto out;
 
 	next_timer = timerqueue_getnext(&base->active);
 	timerqueue_del(&base->active, &timer->node);
 	if (!timerqueue_getnext(&base->active))
-		base->cpu_base->active_bases &= ~(1 << base->index);
+		cpu_base->active_bases &= ~(1 << base->index);
 
 	if (&timer->node == next_timer) {
 #ifdef CONFIG_HIGH_RES_TIMERS
 		/* Reprogram the clock event device. if enabled */
-		if (reprogram && hrtimer_hres_active()) {
+		if (reprogram && cpu_base->hres_active) {
 			ktime_t expires;
 
 			expires = ktime_sub(hrtimer_get_expires(timer),
 					    base->offset);
-			if (base->cpu_base->expires_next.tv64 == expires.tv64)
-				hrtimer_force_reprogram(base->cpu_base, 1);
+			if (cpu_base->expires_next.tv64 == expires.tv64)
+				hrtimer_force_reprogram(cpu_base, 1);
 		}
 #endif
 	}

@@ -1106,7 +1114,7 @@ ktime_t hrtimer_get_next_event(void)
 
 	raw_spin_lock_irqsave(&cpu_base->lock, flags);
 
-	if (!hrtimer_hres_active())
+	if (!__hrtimer_hres_active(cpu_base))
 		mindelta = ktime_sub(__hrtimer_get_next_event(cpu_base),
 				     ktime_get());
 

@@ -1404,7 +1412,7 @@ void hrtimer_run_queues(void)
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t now;
 
-	if (hrtimer_hres_active())
+	if (__hrtimer_hres_active(cpu_base))
 		return;
 
 	raw_spin_lock(&cpu_base->lock);

Index: tip/kernel/time/hrtimer.c
===================================================================
@@ -419,16 +419,16 @@ static ktime_t __hrtimer_get_next_event(
 {
 	struct hrtimer_clock_base *base = cpu_base->clock_base;
 	ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
-	int i;
+	unsigned int active = cpu_base->active_bases;
 
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
+	for (; active; base++, active >>= 1) {
 		struct timerqueue_node *next;
 		struct hrtimer *timer;
 
-		next = timerqueue_getnext(&base->active);
-		if (!next)
+		if (!(active & 0x01))
 			continue;
 
+		next = timerqueue_getnext(&base->active);
 		timer = container_of(next, struct hrtimer, node);
 		expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 		if (expires.tv64 < expires_next.tv64)

@@ -1206,17 +1206,16 @@ static void __run_hrtimer(struct hrtimer
 
 static void __hrtimer_run_queues(struct hrtimer_cpu_base *cpu_base, ktime_t now)
 {
-	int i;
+	struct hrtimer_clock_base *base = cpu_base->clock_base;
+	unsigned int active = cpu_base->active_bases;
 
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-		struct hrtimer_clock_base *base;
+	for (; active; base++, active >>= 1) {
 		struct timerqueue_node *node;
 		ktime_t basenow;
 
-		if (!(cpu_base->active_bases & (1 << i)))
+		if (!(active & 0x01))
 			continue;
 
-		base = cpu_base->clock_base + i;
 		basenow = ktime_add(now, base->offset);
 
 		while ((node = timerqueue_getnext(&base->active))) {

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -191,7 +191,7 @@ struct hrtimer_cpu_base {
 	unsigned int			max_hang_time;
 #endif
 	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
-};
+} ____cacheline_aligned;
 
 static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
 {

Index: tip/include/linux/hrtimer.h
===================================================================
@@ -130,6 +130,12 @@ struct hrtimer_sleeper {
 	struct task_struct *task;
 };
 
+#ifdef CONFIG_64BIT
+# define HRTIMER_CLOCK_BASE_ALIGN	64
+#else
+# define HRTIMER_CLOCK_BASE_ALIGN	32
+#endif
+
 /**
  * struct hrtimer_clock_base - the timer base for a specific clock
  * @cpu_base:		per cpu clock base