1/*
2 * kernel/time/timer_list.c
3 *
4 * List pending timers
5 *
6 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/proc_fs.h>
14#include <linux/module.h>
15#include <linux/spinlock.h>
16#include <linux/sched.h>
17#include <linux/seq_file.h>
18#include <linux/kallsyms.h>
19
20#include <asm/uaccess.h>
21
22#include "tick-internal.h"
23
24struct timer_list_iter {
25	int cpu;
26	bool second_pass;
27	u64 now;
28};
29
30typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
31
32DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
33
34/*
35 * This allows printing both to /proc/timer_list and
36 * to the console (on SysRq-Q):
37 */
38#define SEQ_printf(m, x...)			\
39 do {						\
40	if (m)					\
41		seq_printf(m, x);		\
42	else					\
43		printk(x);			\
44 } while (0)
45
46static void print_name_offset(struct seq_file *m, void *sym)
47{
48	char symname[KSYM_NAME_LEN];
49
50	if (lookup_symbol_name((unsigned long)sym, symname) < 0)
51		SEQ_printf(m, "<%pK>", sym);
52	else
53		SEQ_printf(m, "%s", symname);
54}
55
56static void
57print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
58	    int idx, u64 now)
59{
60#ifdef CONFIG_TIMER_STATS
61	char tmp[TASK_COMM_LEN + 1];
62#endif
63	SEQ_printf(m, " #%d: ", idx);
64	print_name_offset(m, taddr);
65	SEQ_printf(m, ", ");
66	print_name_offset(m, timer->function);
67	SEQ_printf(m, ", S:%02lx", timer->state);
68#ifdef CONFIG_TIMER_STATS
69	SEQ_printf(m, ", ");
70	print_name_offset(m, timer->start_site);
71	memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
72	tmp[TASK_COMM_LEN] = 0;
73	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
74#endif
75	SEQ_printf(m, "\n");
76	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
77		(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
78		(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
79		(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
80		(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
81}
82
83static void
84print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
85		    u64 now)
86{
87	struct hrtimer *timer, tmp;
88	unsigned long next = 0, i;
89	struct timerqueue_node *curr;
90	unsigned long flags;
91
92next_one:
93	i = 0;
94	raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
95
96	curr = timerqueue_getnext(&base->active);
97	/*
98	 * Crude but we have to do this O(N*N) thing, because
99	 * we have to unlock the base when printing:
100	 */
101	while (curr && i < next) {
102		curr = timerqueue_iterate_next(curr);
103		i++;
104	}
105
106	if (curr) {
107
108		timer = container_of(curr, struct hrtimer, node);
109		tmp = *timer;
110		raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
111
112		print_timer(m, timer, &tmp, i, now);
113		next++;
114		goto next_one;
115	}
116	raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
117}
118
119static void
120print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
121{
122	SEQ_printf(m, "  .base:       %pK\n", base);
123	SEQ_printf(m, "  .index:      %d\n",
124			base->index);
125	SEQ_printf(m, "  .resolution: %Lu nsecs\n",
126			(unsigned long long)ktime_to_ns(base->resolution));
127	SEQ_printf(m,   "  .get_time:   ");
128	print_name_offset(m, base->get_time);
129	SEQ_printf(m,   "\n");
130#ifdef CONFIG_HIGH_RES_TIMERS
131	SEQ_printf(m, "  .offset:     %Lu nsecs\n",
132		   (unsigned long long) ktime_to_ns(base->offset));
133#endif
134	SEQ_printf(m,   "active timers:\n");
135	print_active_timers(m, base, now);
136}
137
138static void print_cpu(struct seq_file *m, int cpu, u64 now)
139{
140	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
141	int i;
142
143	SEQ_printf(m, "cpu: %d\n", cpu);
144	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
145		SEQ_printf(m, " clock %d:\n", i);
146		print_base(m, cpu_base->clock_base + i, now);
147	}
148#define P(x) \
149	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
150		   (unsigned long long)(cpu_base->x))
151#define P_ns(x) \
152	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
153		   (unsigned long long)(ktime_to_ns(cpu_base->x)))
154
155#ifdef CONFIG_HIGH_RES_TIMERS
156	P_ns(expires_next);
157	P(hres_active);
158	P(nr_events);
159	P(nr_retries);
160	P(nr_hangs);
161	P_ns(max_hang_time);
162#endif
163#undef P
164#undef P_ns
165
166#ifdef CONFIG_TICK_ONESHOT
167# define P(x) \
168	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
169		   (unsigned long long)(ts->x))
170# define P_ns(x) \
171	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
172		   (unsigned long long)(ktime_to_ns(ts->x)))
173	{
174		struct tick_sched *ts = tick_get_tick_sched(cpu);
175		P(nohz_mode);
176		P_ns(last_tick);
177		P(tick_stopped);
178		P(idle_jiffies);
179		P(idle_calls);
180		P(idle_sleeps);
181		P_ns(idle_entrytime);
182		P_ns(idle_waketime);
183		P_ns(idle_exittime);
184		P_ns(idle_sleeptime);
185		P_ns(iowait_sleeptime);
186		P(last_jiffies);
187		P(next_jiffies);
188		P_ns(idle_expires);
189		SEQ_printf(m, "jiffies: %Lu\n",
190			   (unsigned long long)jiffies);
191	}
192#endif
193
194#undef P
195#undef P_ns
196	SEQ_printf(m, "\n");
197}
198
199#ifdef CONFIG_GENERIC_CLOCKEVENTS
200static void
201print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
202{
203	struct clock_event_device *dev = td->evtdev;
204
205	SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
206	if (cpu < 0)
207		SEQ_printf(m, "Broadcast device\n");
208	else
209		SEQ_printf(m, "Per CPU device: %d\n", cpu);
210
211	SEQ_printf(m, "Clock Event Device: ");
212	if (!dev) {
213		SEQ_printf(m, "<NULL>\n");
214		return;
215	}
216	SEQ_printf(m, "%s\n", dev->name);
217	SEQ_printf(m, " max_delta_ns:   %llu\n",
218		   (unsigned long long) dev->max_delta_ns);
219	SEQ_printf(m, " min_delta_ns:   %llu\n",
220		   (unsigned long long) dev->min_delta_ns);
221	SEQ_printf(m, " mult:           %u\n", dev->mult);
222	SEQ_printf(m, " shift:          %u\n", dev->shift);
223	SEQ_printf(m, " mode:           %d\n", dev->mode);
224	SEQ_printf(m, " next_event:     %Ld nsecs\n",
225		   (unsigned long long) ktime_to_ns(dev->next_event));
226
227	SEQ_printf(m, " set_next_event: ");
228	print_name_offset(m, dev->set_next_event);
229	SEQ_printf(m, "\n");
230
231	if (dev->set_mode) {
232		SEQ_printf(m, " set_mode:       ");
233		print_name_offset(m, dev->set_mode);
234		SEQ_printf(m, "\n");
235	} else {
236		if (dev->set_state_shutdown) {
237			SEQ_printf(m, " shutdown: ");
238			print_name_offset(m, dev->set_state_shutdown);
239			SEQ_printf(m, "\n");
240		}
241
242		if (dev->set_state_periodic) {
243			SEQ_printf(m, " periodic: ");
244			print_name_offset(m, dev->set_state_periodic);
245			SEQ_printf(m, "\n");
246		}
247
248		if (dev->set_state_oneshot) {
249			SEQ_printf(m, " oneshot:  ");
250			print_name_offset(m, dev->set_state_oneshot);
251			SEQ_printf(m, "\n");
252		}
253
254		if (dev->tick_resume) {
255			SEQ_printf(m, " resume:   ");
256			print_name_offset(m, dev->tick_resume);
257			SEQ_printf(m, "\n");
258		}
259	}
260
261	SEQ_printf(m, " event_handler:  ");
262	print_name_offset(m, dev->event_handler);
263	SEQ_printf(m, "\n");
264	SEQ_printf(m, " retries:        %lu\n", dev->retries);
265	SEQ_printf(m, "\n");
266}
267
268static void timer_list_show_tickdevices_header(struct seq_file *m)
269{
270#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
271	print_tickdevice(m, tick_get_broadcast_device(), -1);
272	SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
273		   cpumask_bits(tick_get_broadcast_mask())[0]);
274#ifdef CONFIG_TICK_ONESHOT
275	SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
276		   cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
277#endif
278	SEQ_printf(m, "\n");
279#endif
280}
281#endif
282
283static inline void timer_list_header(struct seq_file *m, u64 now)
284{
285	SEQ_printf(m, "Timer List Version: v0.7\n");
286	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
287	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
288	SEQ_printf(m, "\n");
289}
290
291static int timer_list_show(struct seq_file *m, void *v)
292{
293	struct timer_list_iter *iter = v;
294
295	if (iter->cpu == -1 && !iter->second_pass)
296		timer_list_header(m, iter->now);
297	else if (!iter->second_pass)
298		print_cpu(m, iter->cpu, iter->now);
299#ifdef CONFIG_GENERIC_CLOCKEVENTS
300	else if (iter->cpu == -1 && iter->second_pass)
301		timer_list_show_tickdevices_header(m);
302	else
303		print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
304#endif
305	return 0;
306}
307
308void sysrq_timer_list_show(void)
309{
310	u64 now = ktime_to_ns(ktime_get());
311	int cpu;
312
313	timer_list_header(NULL, now);
314
315	for_each_online_cpu(cpu)
316		print_cpu(NULL, cpu, now);
317
318#ifdef CONFIG_GENERIC_CLOCKEVENTS
319	timer_list_show_tickdevices_header(NULL);
320	for_each_online_cpu(cpu)
321		print_tickdevice(NULL, tick_get_device(cpu), cpu);
322#endif
323	return;
324}
325
326static void *move_iter(struct timer_list_iter *iter, loff_t offset)
327{
328	for (; offset; offset--) {
329		iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
330		if (iter->cpu >= nr_cpu_ids) {
331#ifdef CONFIG_GENERIC_CLOCKEVENTS
332			if (!iter->second_pass) {
333				iter->cpu = -1;
334				iter->second_pass = true;
335			} else
336				return NULL;
337#else
338			return NULL;
339#endif
340		}
341	}
342	return iter;
343}
344
345static void *timer_list_start(struct seq_file *file, loff_t *offset)
346{
347	struct timer_list_iter *iter = file->private;
348
349	if (!*offset)
350		iter->now = ktime_to_ns(ktime_get());
351	iter->cpu = -1;
352	iter->second_pass = false;
353	return move_iter(iter, *offset);
354}
355
356static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
357{
358	struct timer_list_iter *iter = file->private;
359	++*offset;
360	return move_iter(iter, 1);
361}
362
363static void timer_list_stop(struct seq_file *seq, void *v)
364{
365}
366
367static const struct seq_operations timer_list_sops = {
368	.start = timer_list_start,
369	.next = timer_list_next,
370	.stop = timer_list_stop,
371	.show = timer_list_show,
372};
373
374static int timer_list_open(struct inode *inode, struct file *filp)
375{
376	return seq_open_private(filp, &timer_list_sops,
377			sizeof(struct timer_list_iter));
378}
379
380static const struct file_operations timer_list_fops = {
381	.open		= timer_list_open,
382	.read		= seq_read,
383	.llseek		= seq_lseek,
384	.release	= seq_release_private,
385};
386
387static int __init init_timer_list_procfs(void)
388{
389	struct proc_dir_entry *pe;
390
391	pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
392	if (!pe)
393		return -ENOMEM;
394	return 0;
395}
396__initcall(init_timer_list_procfs);
397