summaryrefslogtreecommitdiff
path: root/kernel/time/timer_list.c
blob: 129c96033e466cea9e804cb2136348f6eb335e7c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
/*
 * kernel/time/timer_list.c
 *
 * List pending timers
 *
 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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 <asm/uaccess.h>

#include "tick-internal.h"

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

typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);

/*
 * 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_name_offset(struct seq_file *m, void *sym)
{
	char symname[KSYM_NAME_LEN];

	if (lookup_symbol_name((unsigned long)sym, symname) < 0)
		SEQ_printf(m, "<%pK>", sym);
	else
		SEQ_printf(m, "%s", symname);
}

static void
print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
	    int idx, u64 now)
{
#ifdef CONFIG_TIMER_STATS
	char tmp[TASK_COMM_LEN + 1];
#endif
	SEQ_printf(m, " #%d: ", idx);
	print_name_offset(m, taddr);
	SEQ_printf(m, ", ");
	print_name_offset(m, timer->function);
	SEQ_printf(m, ", S:%02lx", timer->state);
#ifdef CONFIG_TIMER_STATS
	SEQ_printf(m, ", ");
	print_name_offset(m, timer->start_site);
	memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
	tmp[TASK_COMM_LEN] = 0;
	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
#endif
	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;
	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", (unsigned) hrtimer_resolution);

	SEQ_printf(m,   "  .get_time:   ");
	print_name_offset(m, base->get_time);
	SEQ_printf(m,   "\n");
#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;

	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", dev->mode);
	SEQ_printf(m, " next_event:     %Ld nsecs\n",
		   (unsigned long long) ktime_to_ns(dev->next_event));

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

	if (dev->set_mode) {
		SEQ_printf(m, " set_mode:       ");
		print_name_offset(m, dev->set_mode);
		SEQ_printf(m, "\n");
	} else {
		if (dev->set_state_shutdown) {
			SEQ_printf(m, " shutdown: ");
			print_name_offset(m, dev->set_state_shutdown);
			SEQ_printf(m, "\n");
		}

		if (dev->set_state_periodic) {
			SEQ_printf(m, " periodic: ");
			print_name_offset(m, dev->set_state_periodic);
			SEQ_printf(m, "\n");
		}

		if (dev->set_state_oneshot) {
			SEQ_printf(m, " oneshot:  ");
			print_name_offset(m, dev->set_state_oneshot);
			SEQ_printf(m, "\n");
		}

		if (dev->set_state_oneshot_stopped) {
			SEQ_printf(m, " oneshot stopped: ");
			print_name_offset(m, dev->set_state_oneshot_stopped);
			SEQ_printf(m, "\n");
		}

		if (dev->tick_resume) {
			SEQ_printf(m, " resume:   ");
			print_name_offset(m, dev->tick_resume);
			SEQ_printf(m, "\n");
		}
	}

	SEQ_printf(m, " event_handler:  ");
	print_name_offset(m, dev->event_handler);
	SEQ_printf(m, "\n");
	SEQ_printf(m, " retries:        %lu\n", dev->retries);
	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: v0.8\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");
}

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;
}

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;
}

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 timer_list_open(struct inode *inode, struct file *filp)
{
	return seq_open_private(filp, &timer_list_sops,
			sizeof(struct timer_list_iter));
}

static const struct file_operations timer_list_fops = {
	.open		= timer_list_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_private,
};

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

	pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
	if (!pe)
		return -ENOMEM;
	return 0;
}
__initcall(init_timer_list_procfs);