kernel/time/timer_list.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * List pending timers
  *
  * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
  */

 #include <linux/proc_fs.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <linux/kallsyms.h>
 #include <linux/nmi.h>

 #include <linux/uaccess.h>

 #include "tick-internal.h"

 struct timer_list_iter {
 	int cpu;
 	bool second_pass;
 	u64 now;
 };

 /*
  * This allows printing both to /proc/timer_list and
  * to the console (on SysRq-Q):
  */
 __printf(2, 3)
 static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
 {
 	va_list args;

 	va_start(args, fmt);

 	if (m)
 		seq_vprintf(m, fmt, args);
 	else
 		vprintk(fmt, args);

 	va_end(args);
 }

 static void
 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
 	    int idx, u64 now)
 {
 	SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function);
 	SEQ_printf(m, ", S:%02x", timer->state);
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
 		(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
 		(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
 		(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
 		(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
 }

 static void
 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
 		    u64 now)
 {
 	struct hrtimer *timer, tmp;
 	unsigned long next = 0, i;
 	struct timerqueue_node *curr;
 	unsigned long flags;

 next_one:
 	i = 0;

 	touch_nmi_watchdog();

 	raw_spin_lock_irqsave(&base->cpu_base->lock, flags);

 	curr = timerqueue_getnext(&base->active);
 	/*
 	 * Crude but we have to do this O(N*N) thing, because
 	 * we have to unlock the base when printing:
 	 */
 	while (curr && i < next) {
 		curr = timerqueue_iterate_next(curr);
 		i++;
 	}

 	if (curr) {

 		timer = container_of(curr, struct hrtimer, node);
 		tmp = *timer;
 		raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);

 		print_timer(m, timer, &tmp, i, now);
 		next++;
 		goto next_one;
 	}
 	raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 }

 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: %u nsecs\n", hrtimer_resolution);

 	SEQ_printf(m,   "  .get_time:   %ps\n", base->get_time);
 #ifdef CONFIG_HIGH_RES_TIMERS
 	SEQ_printf(m, "  .offset:     %Lu nsecs\n",
 		   (unsigned long long) ktime_to_ns(base->offset));
 #endif
 	SEQ_printf(m,   "active timers:\n");
 	print_active_timers(m, base, now + ktime_to_ns(base->offset));
 }

 static void print_cpu(struct seq_file *m, int cpu, u64 now)
 {
 	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
 	int i;

 	SEQ_printf(m, "cpu: %d\n", cpu);
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
 		SEQ_printf(m, " clock %d:\n", i);
 		print_base(m, cpu_base->clock_base + i, now);
 	}
 #define P(x) \
 	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 		   (unsigned long long)(cpu_base->x))
 #define P_ns(x) \
 	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 		   (unsigned long long)(ktime_to_ns(cpu_base->x)))

 #ifdef CONFIG_HIGH_RES_TIMERS
 	P_ns(expires_next);
 	P(hres_active);
 	P(nr_events);
 	P(nr_retries);
 	P(nr_hangs);
 	P(max_hang_time);
 #endif
 #undef P
 #undef P_ns

 #ifdef CONFIG_TICK_ONESHOT
 # define P(x) \
 	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 		   (unsigned long long)(ts->x))
 # define P_ns(x) \
 	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 		   (unsigned long long)(ktime_to_ns(ts->x)))
 	{
 		struct tick_sched *ts = tick_get_tick_sched(cpu);
 		P(nohz_mode);
 		P_ns(last_tick);
 		P(tick_stopped);
 		P(idle_jiffies);
 		P(idle_calls);
 		P(idle_sleeps);
 		P_ns(idle_entrytime);
 		P_ns(idle_waketime);
 		P_ns(idle_exittime);
 		P_ns(idle_sleeptime);
 		P_ns(iowait_sleeptime);
 		P(last_jiffies);
 		P(next_timer);
 		P_ns(idle_expires);
 		SEQ_printf(m, "jiffies: %Lu\n",
 			   (unsigned long long)jiffies);
 	}
 #endif

 #undef P
 #undef P_ns
 	SEQ_printf(m, "\n");
 }

 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 static void
 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
 {
 	struct clock_event_device *dev = td->evtdev;

 	touch_nmi_watchdog();

 	SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
 	if (cpu < 0)
 		SEQ_printf(m, "Broadcast device\n");
 	else
 		SEQ_printf(m, "Per CPU device: %d\n", cpu);

 	SEQ_printf(m, "Clock Event Device: ");
 	if (!dev) {
 		SEQ_printf(m, "<NULL>\n");
 		return;
 	}
 	SEQ_printf(m, "%s\n", dev->name);
 	SEQ_printf(m, " max_delta_ns:   %llu\n",
 		   (unsigned long long) dev->max_delta_ns);
 	SEQ_printf(m, " min_delta_ns:   %llu\n",
 		   (unsigned long long) dev->min_delta_ns);
 	SEQ_printf(m, " mult:           %u\n", dev->mult);
 	SEQ_printf(m, " shift:          %u\n", dev->shift);
 	SEQ_printf(m, " mode:           %d\n", clockevent_get_state(dev));
 	SEQ_printf(m, " next_event:     %Ld nsecs\n",
 		   (unsigned long long) ktime_to_ns(dev->next_event));

 	SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);

 	if (dev->set_state_shutdown)
 		SEQ_printf(m, " shutdown:       %ps\n",
 			dev->set_state_shutdown);

 	if (dev->set_state_periodic)
 		SEQ_printf(m, " periodic:       %ps\n",
 			dev->set_state_periodic);

 	if (dev->set_state_oneshot)
 		SEQ_printf(m, " oneshot:        %ps\n",
 			dev->set_state_oneshot);

 	if (dev->set_state_oneshot_stopped)
 		SEQ_printf(m, " oneshot stopped: %ps\n",
 			dev->set_state_oneshot_stopped);

 	if (dev->tick_resume)
 		SEQ_printf(m, " resume:         %ps\n",
 			dev->tick_resume);

 	SEQ_printf(m, " event_handler:  %ps\n", dev->event_handler);
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, " retries:        %lu\n", dev->retries);

 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 	if (cpu >= 0) {
 		const struct clock_event_device *wd = tick_get_wakeup_device(cpu);

 		SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
 	}
 #endif
 	SEQ_printf(m, "\n");
 }

 static void timer_list_show_tickdevices_header(struct seq_file *m)
 {
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 	print_tickdevice(m, tick_get_broadcast_device(), -1);
 	SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
 		   cpumask_pr_args(tick_get_broadcast_mask()));
 #ifdef CONFIG_TICK_ONESHOT
 	SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
 		   cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
 #endif
 	SEQ_printf(m, "\n");
 #endif
 }
 #endif

 static inline void timer_list_header(struct seq_file *m, u64 now)
 {
 	SEQ_printf(m, "Timer List Version: v0.9\n");
 	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
 	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
 	SEQ_printf(m, "\n");
 }

 void sysrq_timer_list_show(void)
 {
 	u64 now = ktime_to_ns(ktime_get());
 	int cpu;

 	timer_list_header(NULL, now);

 	for_each_online_cpu(cpu)
 		print_cpu(NULL, cpu, now);

 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 	timer_list_show_tickdevices_header(NULL);
 	for_each_online_cpu(cpu)
 		print_tickdevice(NULL, tick_get_device(cpu), cpu);
 #endif
 	return;
 }

 #ifdef CONFIG_PROC_FS
 static int timer_list_show(struct seq_file *m, void *v)
 {
 	struct timer_list_iter *iter = v;

 	if (iter->cpu == -1 && !iter->second_pass)
 		timer_list_header(m, iter->now);
 	else if (!iter->second_pass)
 		print_cpu(m, iter->cpu, iter->now);
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 	else if (iter->cpu == -1 && iter->second_pass)
 		timer_list_show_tickdevices_header(m);
 	else
 		print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
 #endif
 	return 0;
 }

 static void *move_iter(struct timer_list_iter *iter, loff_t offset)
 {
 	for (; offset; offset--) {
 		iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
 		if (iter->cpu >= nr_cpu_ids) {
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 			if (!iter->second_pass) {
 				iter->cpu = -1;
 				iter->second_pass = true;
 			} else
 				return NULL;
 #else
 			return NULL;
 #endif
 		}
 	}
 	return iter;
 }

 static void *timer_list_start(struct seq_file *file, loff_t *offset)
 {
 	struct timer_list_iter *iter = file->private;

 	if (!*offset)
 		iter->now = ktime_to_ns(ktime_get());
 	iter->cpu = -1;
 	iter->second_pass = false;
 	return move_iter(iter, *offset);
 }

 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
 {
 	struct timer_list_iter *iter = file->private;
 	++*offset;
 	return move_iter(iter, 1);
 }

 static void timer_list_stop(struct seq_file *seq, void *v)
 {
 }

 static const struct seq_operations timer_list_sops = {
 	.start = timer_list_start,
 	.next = timer_list_next,
 	.stop = timer_list_stop,
 	.show = timer_list_show,
 };

 static int __init init_timer_list_procfs(void)
 {
 	struct proc_dir_entry *pe;

 	pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
 			sizeof(struct timer_list_iter), NULL);
 	if (!pe)
 		return -ENOMEM;
 	return 0;
 }
 __initcall(init_timer_list_procfs);
 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* List pending timers
	*
	* Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
	*/

	#include <linux/proc_fs.h>
	#include <linux/module.h>
	#include <linux/spinlock.h>
	#include <linux/sched.h>
	#include <linux/seq_file.h>
	#include <linux/kallsyms.h>
	#include <linux/nmi.h>

	#include <linux/uaccess.h>

	#include "tick-internal.h"

	struct timer_list_iter {
	int cpu;
	bool second_pass;
	u64 now;
	};

	/*
	* This allows printing both to /proc/timer_list and
	* to the console (on SysRq-Q):
	*/
	__printf(2, 3)
	static void SEQ_printf(struct seq_file m, const char fmt, ...)
	{
	va_list args;

	va_start(args, fmt);

	if (m)
	seq_vprintf(m, fmt, args);
	else
	vprintk(fmt, args);

	va_end(args);
	}

	static void
	print_timer(struct seq_file m, struct hrtimer taddr, struct hrtimer *timer,
	int idx, u64 now)
	{
	SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function);
	SEQ_printf(m, ", S:%02x", timer->state);
	SEQ_printf(m, "\n");
	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
	(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
	(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
	(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
	(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
	}

	static void
	print_active_timers(struct seq_file m, struct hrtimer_clock_base base,
	u64 now)
	{
	struct hrtimer *timer, tmp;
	unsigned long next = 0, i;
	struct timerqueue_node *curr;
	unsigned long flags;

	next_one:
	i = 0;

	touch_nmi_watchdog();

	raw_spin_lock_irqsave(&base->cpu_base->lock, flags);

	curr = timerqueue_getnext(&base->active);
	/*
	* Crude but we have to do this O(N*N) thing, because
	* we have to unlock the base when printing:
	*/
	while (curr && i < next) {
	curr = timerqueue_iterate_next(curr);
	i++;
	}

	if (curr) {

	timer = container_of(curr, struct hrtimer, node);
	tmp = *timer;
	raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);

	print_timer(m, timer, &tmp, i, now);
	next++;
	goto next_one;
	}
	raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
	}

	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: %u nsecs\n", hrtimer_resolution);

	SEQ_printf(m, " .get_time: %ps\n", base->get_time);
	#ifdef CONFIG_HIGH_RES_TIMERS
	SEQ_printf(m, " .offset: %Lu nsecs\n",
	(unsigned long long) ktime_to_ns(base->offset));
	#endif
	SEQ_printf(m, "active timers:\n");
	print_active_timers(m, base, now + ktime_to_ns(base->offset));
	}

	static void print_cpu(struct seq_file *m, int cpu, u64 now)
	{
	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
	int i;

	SEQ_printf(m, "cpu: %d\n", cpu);
	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
	SEQ_printf(m, " clock %d:\n", i);
	print_base(m, cpu_base->clock_base + i, now);
	}
	#define P(x) \
	SEQ_printf(m, " .%-15s: %Lu\n", #x, \
	(unsigned long long)(cpu_base->x))
	#define P_ns(x) \
	SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
	(unsigned long long)(ktime_to_ns(cpu_base->x)))

	#ifdef CONFIG_HIGH_RES_TIMERS
	P_ns(expires_next);
	P(hres_active);
	P(nr_events);
	P(nr_retries);
	P(nr_hangs);
	P(max_hang_time);
	#endif
	#undef P
	#undef P_ns

	#ifdef CONFIG_TICK_ONESHOT
	# define P(x) \
	SEQ_printf(m, " .%-15s: %Lu\n", #x, \
	(unsigned long long)(ts->x))
	# define P_ns(x) \
	SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
	(unsigned long long)(ktime_to_ns(ts->x)))
	{
	struct tick_sched *ts = tick_get_tick_sched(cpu);
	P(nohz_mode);
	P_ns(last_tick);
	P(tick_stopped);
	P(idle_jiffies);
	P(idle_calls);
	P(idle_sleeps);
	P_ns(idle_entrytime);
	P_ns(idle_waketime);
	P_ns(idle_exittime);
	P_ns(idle_sleeptime);
	P_ns(iowait_sleeptime);
	P(last_jiffies);
	P(next_timer);
	P_ns(idle_expires);
	SEQ_printf(m, "jiffies: %Lu\n",
	(unsigned long long)jiffies);
	}
	#endif

	#undef P
	#undef P_ns
	SEQ_printf(m, "\n");
	}

	#ifdef CONFIG_GENERIC_CLOCKEVENTS
	static void
	print_tickdevice(struct seq_file m, struct tick_device td, int cpu)
	{
	struct clock_event_device *dev = td->evtdev;

	touch_nmi_watchdog();

	SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
	if (cpu < 0)
	SEQ_printf(m, "Broadcast device\n");
	else
	SEQ_printf(m, "Per CPU device: %d\n", cpu);

	SEQ_printf(m, "Clock Event Device: ");
	if (!dev) {
	SEQ_printf(m, "<NULL>\n");
	return;
	}
	SEQ_printf(m, "%s\n", dev->name);
	SEQ_printf(m, " max_delta_ns: %llu\n",
	(unsigned long long) dev->max_delta_ns);
	SEQ_printf(m, " min_delta_ns: %llu\n",
	(unsigned long long) dev->min_delta_ns);
	SEQ_printf(m, " mult: %u\n", dev->mult);
	SEQ_printf(m, " shift: %u\n", dev->shift);
	SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev));
	SEQ_printf(m, " next_event: %Ld nsecs\n",
	(unsigned long long) ktime_to_ns(dev->next_event));

	SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);

	if (dev->set_state_shutdown)
	SEQ_printf(m, " shutdown: %ps\n",
	dev->set_state_shutdown);

	if (dev->set_state_periodic)
	SEQ_printf(m, " periodic: %ps\n",
	dev->set_state_periodic);

	if (dev->set_state_oneshot)
	SEQ_printf(m, " oneshot: %ps\n",
	dev->set_state_oneshot);

	if (dev->set_state_oneshot_stopped)
	SEQ_printf(m, " oneshot stopped: %ps\n",
	dev->set_state_oneshot_stopped);

	if (dev->tick_resume)
	SEQ_printf(m, " resume: %ps\n",
	dev->tick_resume);

	SEQ_printf(m, " event_handler: %ps\n", dev->event_handler);
	SEQ_printf(m, "\n");
	SEQ_printf(m, " retries: %lu\n", dev->retries);

	#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	if (cpu >= 0) {
	const struct clock_event_device *wd = tick_get_wakeup_device(cpu);

	SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
	}
	#endif
	SEQ_printf(m, "\n");
	}

	static void timer_list_show_tickdevices_header(struct seq_file *m)
	{
	#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	print_tickdevice(m, tick_get_broadcast_device(), -1);
	SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
	cpumask_pr_args(tick_get_broadcast_mask()));
	#ifdef CONFIG_TICK_ONESHOT
	SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
	cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
	#endif
	SEQ_printf(m, "\n");
	#endif
	}
	#endif

	static inline void timer_list_header(struct seq_file *m, u64 now)
	{
	SEQ_printf(m, "Timer List Version: v0.9\n");
	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
	SEQ_printf(m, "\n");
	}

	void sysrq_timer_list_show(void)
	{
	u64 now = ktime_to_ns(ktime_get());
	int cpu;

	timer_list_header(NULL, now);

	for_each_online_cpu(cpu)
	print_cpu(NULL, cpu, now);

	#ifdef CONFIG_GENERIC_CLOCKEVENTS
	timer_list_show_tickdevices_header(NULL);
	for_each_online_cpu(cpu)
	print_tickdevice(NULL, tick_get_device(cpu), cpu);
	#endif
	return;
	}

	#ifdef CONFIG_PROC_FS
	static int timer_list_show(struct seq_file m, void v)
	{
	struct timer_list_iter *iter = v;

	if (iter->cpu == -1 && !iter->second_pass)
	timer_list_header(m, iter->now);
	else if (!iter->second_pass)
	print_cpu(m, iter->cpu, iter->now);
	#ifdef CONFIG_GENERIC_CLOCKEVENTS
	else if (iter->cpu == -1 && iter->second_pass)
	timer_list_show_tickdevices_header(m);
	else
	print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
	#endif
	return 0;
	}

	static void move_iter(struct timer_list_iter iter, loff_t offset)
	{
	for (; offset; offset--) {
	iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
	if (iter->cpu >= nr_cpu_ids) {
	#ifdef CONFIG_GENERIC_CLOCKEVENTS
	if (!iter->second_pass) {
	iter->cpu = -1;
	iter->second_pass = true;
	} else
	return NULL;
	#else
	return NULL;
	#endif
	}
	}
	return iter;
	}

	static void timer_list_start(struct seq_file file, loff_t *offset)
	{
	struct timer_list_iter *iter = file->private;

	if (!*offset)
	iter->now = ktime_to_ns(ktime_get());
	iter->cpu = -1;
	iter->second_pass = false;
	return move_iter(iter, *offset);
	}

	static void timer_list_next(struct seq_file file, void v, loff_t offset)
	{
	struct timer_list_iter *iter = file->private;
	++*offset;
	return move_iter(iter, 1);
	}

	static void timer_list_stop(struct seq_file seq, void v)
	{
	}

	static const struct seq_operations timer_list_sops = {
	.start = timer_list_start,
	.next = timer_list_next,
	.stop = timer_list_stop,
	.show = timer_list_show,
	};

	static int __init init_timer_list_procfs(void)
	{
	struct proc_dir_entry *pe;

	pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
	sizeof(struct timer_list_iter), NULL);
	if (!pe)
	return -ENOMEM;
	return 0;
	}
	__initcall(init_timer_list_procfs);
	#endif