xref: /linux/kernel/time/timer_list.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 #include <linux/tick.h>
20 
21 #include <asm/uaccess.h>
22 
23 typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
24 
25 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
26 
27 /*
28  * This allows printing both to /proc/timer_list and
29  * to the console (on SysRq-Q):
30  */
31 #define SEQ_printf(m, x...)			\
32  do {						\
33 	if (m)					\
34 		seq_printf(m, x);		\
35 	else					\
36 		printk(x);			\
37  } while (0)
38 
39 static void print_name_offset(struct seq_file *m, void *sym)
40 {
41 	unsigned long addr = (unsigned long)sym;
42 	char namebuf[KSYM_NAME_LEN+1];
43 	unsigned long size, offset;
44 	const char *sym_name;
45 	char *modname;
46 
47 	sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
48 	if (sym_name)
49 		SEQ_printf(m, "%s", sym_name);
50 	else
51 		SEQ_printf(m, "<%p>", sym);
52 }
53 
54 static void
55 print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now)
56 {
57 #ifdef CONFIG_TIMER_STATS
58 	char tmp[TASK_COMM_LEN + 1];
59 #endif
60 	SEQ_printf(m, " #%d: ", idx);
61 	print_name_offset(m, timer);
62 	SEQ_printf(m, ", ");
63 	print_name_offset(m, timer->function);
64 	SEQ_printf(m, ", S:%02lx", timer->state);
65 #ifdef CONFIG_TIMER_STATS
66 	SEQ_printf(m, ", ");
67 	print_name_offset(m, timer->start_site);
68 	memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
69 	tmp[TASK_COMM_LEN] = 0;
70 	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
71 #endif
72 	SEQ_printf(m, "\n");
73 	SEQ_printf(m, " # expires at %Ld nsecs [in %Ld nsecs]\n",
74 		(unsigned long long)ktime_to_ns(timer->expires),
75 		(unsigned long long)(ktime_to_ns(timer->expires) - now));
76 }
77 
78 static void
79 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
80 		    u64 now)
81 {
82 	struct hrtimer *timer, tmp;
83 	unsigned long next = 0, i;
84 	struct rb_node *curr;
85 	unsigned long flags;
86 
87 next_one:
88 	i = 0;
89 	spin_lock_irqsave(&base->cpu_base->lock, flags);
90 
91 	curr = base->first;
92 	/*
93 	 * Crude but we have to do this O(N*N) thing, because
94 	 * we have to unlock the base when printing:
95 	 */
96 	while (curr && i < next) {
97 		curr = rb_next(curr);
98 		i++;
99 	}
100 
101 	if (curr) {
102 
103 		timer = rb_entry(curr, struct hrtimer, node);
104 		tmp = *timer;
105 		spin_unlock_irqrestore(&base->cpu_base->lock, flags);
106 
107 		print_timer(m, &tmp, i, now);
108 		next++;
109 		goto next_one;
110 	}
111 	spin_unlock_irqrestore(&base->cpu_base->lock, flags);
112 }
113 
114 static void
115 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
116 {
117 	SEQ_printf(m, "  .index:      %d\n",
118 			base->index);
119 	SEQ_printf(m, "  .resolution: %Ld nsecs\n",
120 			(unsigned long long)ktime_to_ns(base->resolution));
121 	SEQ_printf(m,   "  .get_time:   ");
122 	print_name_offset(m, base->get_time);
123 	SEQ_printf(m,   "\n");
124 #ifdef CONFIG_HIGH_RES_TIMERS
125 	SEQ_printf(m, "  .offset:     %Ld nsecs\n",
126 			ktime_to_ns(base->offset));
127 #endif
128 	SEQ_printf(m,   "active timers:\n");
129 	print_active_timers(m, base, now);
130 }
131 
132 static void print_cpu(struct seq_file *m, int cpu, u64 now)
133 {
134 	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
135 	int i;
136 
137 	SEQ_printf(m, "\ncpu: %d\n", cpu);
138 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
139 		SEQ_printf(m, " clock %d:\n", i);
140 		print_base(m, cpu_base->clock_base + i, now);
141 	}
142 #define P(x) \
143 	SEQ_printf(m, "  .%-15s: %Ld\n", #x, (u64)(cpu_base->x))
144 #define P_ns(x) \
145 	SEQ_printf(m, "  .%-15s: %Ld nsecs\n", #x, \
146 		(u64)(ktime_to_ns(cpu_base->x)))
147 
148 #ifdef CONFIG_HIGH_RES_TIMERS
149 	P_ns(expires_next);
150 	P(hres_active);
151 	P(nr_events);
152 #endif
153 #undef P
154 #undef P_ns
155 
156 #ifdef CONFIG_TICK_ONESHOT
157 # define P(x) \
158 	SEQ_printf(m, "  .%-15s: %Ld\n", #x, (u64)(ts->x))
159 # define P_ns(x) \
160 	SEQ_printf(m, "  .%-15s: %Ld nsecs\n", #x, \
161 		(u64)(ktime_to_ns(ts->x)))
162 	{
163 		struct tick_sched *ts = tick_get_tick_sched(cpu);
164 		P(nohz_mode);
165 		P_ns(idle_tick);
166 		P(tick_stopped);
167 		P(idle_jiffies);
168 		P(idle_calls);
169 		P(idle_sleeps);
170 		P_ns(idle_entrytime);
171 		P_ns(idle_sleeptime);
172 		P(last_jiffies);
173 		P(next_jiffies);
174 		P_ns(idle_expires);
175 		SEQ_printf(m, "jiffies: %Ld\n", (u64)jiffies);
176 	}
177 #endif
178 
179 #undef P
180 #undef P_ns
181 }
182 
183 #ifdef CONFIG_GENERIC_CLOCKEVENTS
184 static void
185 print_tickdevice(struct seq_file *m, struct tick_device *td)
186 {
187 	struct clock_event_device *dev = td->evtdev;
188 
189 	SEQ_printf(m, "\nTick Device: mode:     %d\n", td->mode);
190 
191 	SEQ_printf(m, "Clock Event Device: ");
192 	if (!dev) {
193 		SEQ_printf(m, "<NULL>\n");
194 		return;
195 	}
196 	SEQ_printf(m, "%s\n", dev->name);
197 	SEQ_printf(m, " max_delta_ns:   %ld\n", dev->max_delta_ns);
198 	SEQ_printf(m, " min_delta_ns:   %ld\n", dev->min_delta_ns);
199 	SEQ_printf(m, " mult:           %ld\n", dev->mult);
200 	SEQ_printf(m, " shift:          %d\n", dev->shift);
201 	SEQ_printf(m, " mode:           %d\n", dev->mode);
202 	SEQ_printf(m, " next_event:     %Ld nsecs\n",
203 		   (unsigned long long) ktime_to_ns(dev->next_event));
204 
205 	SEQ_printf(m, " set_next_event: ");
206 	print_name_offset(m, dev->set_next_event);
207 	SEQ_printf(m, "\n");
208 
209 	SEQ_printf(m, " set_mode:       ");
210 	print_name_offset(m, dev->set_mode);
211 	SEQ_printf(m, "\n");
212 
213 	SEQ_printf(m, " event_handler:  ");
214 	print_name_offset(m, dev->event_handler);
215 	SEQ_printf(m, "\n");
216 }
217 
218 static void timer_list_show_tickdevices(struct seq_file *m)
219 {
220 	int cpu;
221 
222 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
223 	print_tickdevice(m, tick_get_broadcast_device());
224 	SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
225 		   tick_get_broadcast_mask()->bits[0]);
226 #ifdef CONFIG_TICK_ONESHOT
227 	SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
228 		   tick_get_broadcast_oneshot_mask()->bits[0]);
229 #endif
230 	SEQ_printf(m, "\n");
231 #endif
232 	for_each_online_cpu(cpu)
233 		   print_tickdevice(m, tick_get_device(cpu));
234 	SEQ_printf(m, "\n");
235 }
236 #else
237 static void timer_list_show_tickdevices(struct seq_file *m) { }
238 #endif
239 
240 static int timer_list_show(struct seq_file *m, void *v)
241 {
242 	u64 now = ktime_to_ns(ktime_get());
243 	int cpu;
244 
245 	SEQ_printf(m, "Timer List Version: v0.3\n");
246 	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
247 	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
248 
249 	for_each_online_cpu(cpu)
250 		print_cpu(m, cpu, now);
251 
252 	SEQ_printf(m, "\n");
253 	timer_list_show_tickdevices(m);
254 
255 	return 0;
256 }
257 
258 void sysrq_timer_list_show(void)
259 {
260 	timer_list_show(NULL, NULL);
261 }
262 
263 static int timer_list_open(struct inode *inode, struct file *filp)
264 {
265 	return single_open(filp, timer_list_show, NULL);
266 }
267 
268 static struct file_operations timer_list_fops = {
269 	.open		= timer_list_open,
270 	.read		= seq_read,
271 	.llseek		= seq_lseek,
272 	.release	= seq_release,
273 };
274 
275 static int __init init_timer_list_procfs(void)
276 {
277 	struct proc_dir_entry *pe;
278 
279 	pe = create_proc_entry("timer_list", 0644, NULL);
280 	if (!pe)
281 		return -ENOMEM;
282 
283 	pe->proc_fops = &timer_list_fops;
284 
285 	return 0;
286 }
287 __initcall(init_timer_list_procfs);
288