xref: /openbmc/linux/kernel/time/timer_list.c (revision b6dcefde)
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 	char symname[KSYM_NAME_LEN];
42 
43 	if (lookup_symbol_name((unsigned long)sym, symname) < 0)
44 		SEQ_printf(m, "<%p>", sym);
45 	else
46 		SEQ_printf(m, "%s", symname);
47 }
48 
49 static void
50 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
51 	    int idx, u64 now)
52 {
53 #ifdef CONFIG_TIMER_STATS
54 	char tmp[TASK_COMM_LEN + 1];
55 #endif
56 	SEQ_printf(m, " #%d: ", idx);
57 	print_name_offset(m, taddr);
58 	SEQ_printf(m, ", ");
59 	print_name_offset(m, timer->function);
60 	SEQ_printf(m, ", S:%02lx", timer->state);
61 #ifdef CONFIG_TIMER_STATS
62 	SEQ_printf(m, ", ");
63 	print_name_offset(m, timer->start_site);
64 	memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
65 	tmp[TASK_COMM_LEN] = 0;
66 	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
67 #endif
68 	SEQ_printf(m, "\n");
69 	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
70 		(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
71 		(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
72 		(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
73 		(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
74 }
75 
76 static void
77 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
78 		    u64 now)
79 {
80 	struct hrtimer *timer, tmp;
81 	unsigned long next = 0, i;
82 	struct rb_node *curr;
83 	unsigned long flags;
84 
85 next_one:
86 	i = 0;
87 	raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
88 
89 	curr = base->first;
90 	/*
91 	 * Crude but we have to do this O(N*N) thing, because
92 	 * we have to unlock the base when printing:
93 	 */
94 	while (curr && i < next) {
95 		curr = rb_next(curr);
96 		i++;
97 	}
98 
99 	if (curr) {
100 
101 		timer = rb_entry(curr, struct hrtimer, node);
102 		tmp = *timer;
103 		raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
104 
105 		print_timer(m, timer, &tmp, i, now);
106 		next++;
107 		goto next_one;
108 	}
109 	raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
110 }
111 
112 static void
113 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
114 {
115 	SEQ_printf(m, "  .base:       %p\n", base);
116 	SEQ_printf(m, "  .index:      %d\n",
117 			base->index);
118 	SEQ_printf(m, "  .resolution: %Lu nsecs\n",
119 			(unsigned long long)ktime_to_ns(base->resolution));
120 	SEQ_printf(m,   "  .get_time:   ");
121 	print_name_offset(m, base->get_time);
122 	SEQ_printf(m,   "\n");
123 #ifdef CONFIG_HIGH_RES_TIMERS
124 	SEQ_printf(m, "  .offset:     %Lu nsecs\n",
125 		   (unsigned long long) ktime_to_ns(base->offset));
126 #endif
127 	SEQ_printf(m,   "active timers:\n");
128 	print_active_timers(m, base, now);
129 }
130 
131 static void print_cpu(struct seq_file *m, int cpu, u64 now)
132 {
133 	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
134 	int i;
135 
136 	SEQ_printf(m, "\n");
137 	SEQ_printf(m, "cpu: %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: %Lu\n", #x, \
144 		   (unsigned long long)(cpu_base->x))
145 #define P_ns(x) \
146 	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
147 		   (unsigned long long)(ktime_to_ns(cpu_base->x)))
148 
149 #ifdef CONFIG_HIGH_RES_TIMERS
150 	P_ns(expires_next);
151 	P(hres_active);
152 	P(nr_events);
153 	P(nr_retries);
154 	P(nr_hangs);
155 	P_ns(max_hang_time);
156 #endif
157 #undef P
158 #undef P_ns
159 
160 #ifdef CONFIG_TICK_ONESHOT
161 # define P(x) \
162 	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
163 		   (unsigned long long)(ts->x))
164 # define P_ns(x) \
165 	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
166 		   (unsigned long long)(ktime_to_ns(ts->x)))
167 	{
168 		struct tick_sched *ts = tick_get_tick_sched(cpu);
169 		P(nohz_mode);
170 		P_ns(idle_tick);
171 		P(tick_stopped);
172 		P(idle_jiffies);
173 		P(idle_calls);
174 		P(idle_sleeps);
175 		P_ns(idle_entrytime);
176 		P_ns(idle_waketime);
177 		P_ns(idle_exittime);
178 		P_ns(idle_sleeptime);
179 		P(last_jiffies);
180 		P(next_jiffies);
181 		P_ns(idle_expires);
182 		SEQ_printf(m, "jiffies: %Lu\n",
183 			   (unsigned long long)jiffies);
184 	}
185 #endif
186 
187 #undef P
188 #undef P_ns
189 }
190 
191 #ifdef CONFIG_GENERIC_CLOCKEVENTS
192 static void
193 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
194 {
195 	struct clock_event_device *dev = td->evtdev;
196 
197 	SEQ_printf(m, "\n");
198 	SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
199 	if (cpu < 0)
200 		SEQ_printf(m, "Broadcast device\n");
201 	else
202 		SEQ_printf(m, "Per CPU device: %d\n", cpu);
203 
204 	SEQ_printf(m, "Clock Event Device: ");
205 	if (!dev) {
206 		SEQ_printf(m, "<NULL>\n");
207 		return;
208 	}
209 	SEQ_printf(m, "%s\n", dev->name);
210 	SEQ_printf(m, " max_delta_ns:   %llu\n",
211 		   (unsigned long long) dev->max_delta_ns);
212 	SEQ_printf(m, " min_delta_ns:   %llu\n",
213 		   (unsigned long long) dev->min_delta_ns);
214 	SEQ_printf(m, " mult:           %u\n", dev->mult);
215 	SEQ_printf(m, " shift:          %u\n", dev->shift);
216 	SEQ_printf(m, " mode:           %d\n", dev->mode);
217 	SEQ_printf(m, " next_event:     %Ld nsecs\n",
218 		   (unsigned long long) ktime_to_ns(dev->next_event));
219 
220 	SEQ_printf(m, " set_next_event: ");
221 	print_name_offset(m, dev->set_next_event);
222 	SEQ_printf(m, "\n");
223 
224 	SEQ_printf(m, " set_mode:       ");
225 	print_name_offset(m, dev->set_mode);
226 	SEQ_printf(m, "\n");
227 
228 	SEQ_printf(m, " event_handler:  ");
229 	print_name_offset(m, dev->event_handler);
230 	SEQ_printf(m, "\n");
231 }
232 
233 static void timer_list_show_tickdevices(struct seq_file *m)
234 {
235 	int cpu;
236 
237 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
238 	print_tickdevice(m, tick_get_broadcast_device(), -1);
239 	SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
240 		   cpumask_bits(tick_get_broadcast_mask())[0]);
241 #ifdef CONFIG_TICK_ONESHOT
242 	SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
243 		   cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
244 #endif
245 	SEQ_printf(m, "\n");
246 #endif
247 	for_each_online_cpu(cpu)
248 		print_tickdevice(m, tick_get_device(cpu), cpu);
249 	SEQ_printf(m, "\n");
250 }
251 #else
252 static void timer_list_show_tickdevices(struct seq_file *m) { }
253 #endif
254 
255 static int timer_list_show(struct seq_file *m, void *v)
256 {
257 	u64 now = ktime_to_ns(ktime_get());
258 	int cpu;
259 
260 	SEQ_printf(m, "Timer List Version: v0.5\n");
261 	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
262 	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
263 
264 	for_each_online_cpu(cpu)
265 		print_cpu(m, cpu, now);
266 
267 	SEQ_printf(m, "\n");
268 	timer_list_show_tickdevices(m);
269 
270 	return 0;
271 }
272 
273 void sysrq_timer_list_show(void)
274 {
275 	timer_list_show(NULL, NULL);
276 }
277 
278 static int timer_list_open(struct inode *inode, struct file *filp)
279 {
280 	return single_open(filp, timer_list_show, NULL);
281 }
282 
283 static const struct file_operations timer_list_fops = {
284 	.open		= timer_list_open,
285 	.read		= seq_read,
286 	.llseek		= seq_lseek,
287 	.release	= single_release,
288 };
289 
290 static int __init init_timer_list_procfs(void)
291 {
292 	struct proc_dir_entry *pe;
293 
294 	pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
295 	if (!pe)
296 		return -ENOMEM;
297 	return 0;
298 }
299 __initcall(init_timer_list_procfs);
300