aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/time/timer_list.c
blob: 1a4a7dd787779345eafb02bc5781973cf68a1d6a (plain) (blame)
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
/*
 * 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 <linux/tick.h>

#include <asm/uaccess.h>

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

DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);

/*
 * This allows printing both to /proc/timer_list and
 * to the console (on SysRq-Q):
 */
#define SEQ_printf(m, x...)			\
 do {						\
	if (m)					\
		seq_printf(m, x);		\
	else					\
		printk(x);			\
 } while (0)

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, "<%p>", 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 rb_node *curr;
	unsigned long flags;

next_one:
	i = 0;
	raw_spin_lock_irqsave(&base->cpu_base->lock, flags);

	curr = base->first;
	/*
	 * 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 = rb_next(curr);
		i++;
	}

	if (curr) {

		timer = rb_entry(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:       %p\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,   "  .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);
}

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, "\n");
	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_ns(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(idle_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(last_jiffies);
		P(next_jiffies);
		P_ns(idle_expires);
		SEQ_printf(m, "jiffies: %Lu\n",
			   (unsigned long long)jiffies);
	}
#endif

#undef P
#undef P_ns
}

#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, "\n");
	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");

	SEQ_printf(m, " set_mode:       ");
	print_name_offset(m, dev->set_mode);
	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);
}

static void timer_list_show_tickdevices(struct seq_file *m)
{
	int cpu;

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	print_tickdevice(m, tick_get_broadcast_device(), -1);
	SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
		   cpumask_bits(tick_get_broadcast_mask())[0]);
#ifdef CONFIG_TICK_ONESHOT
	SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
		   cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
#endif
	SEQ_printf(m, "\n");
#endif
	for_each_online_cpu(cpu)
		print_tickdevice(m, tick_get_device(cpu), cpu);
	SEQ_printf(m, "\n");
}
#else
static void timer_list_show_tickdevices(struct seq_file *m) { }
#endif

static int timer_list_show(struct seq_file *m, void *v)
{
	u64 now = ktime_to_ns(ktime_get());
	int cpu;

	SEQ_printf(m, "Timer List Version: v0.6\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);

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

	SEQ_printf(m, "\n");
	timer_list_show_tickdevices(m);

	return 0;
}

void sysrq_timer_list_show(void)
{
	timer_list_show(NULL, NULL);
}

static int timer_list_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, timer_list_show, NULL);
}

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

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);