xref: /openbmc/linux/kernel/time/timer_list.c (revision 22246614)
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 *timer, int idx, u64 now)
51 {
52 #ifdef CONFIG_TIMER_STATS
53 	char tmp[TASK_COMM_LEN + 1];
54 #endif
55 	SEQ_printf(m, " #%d: ", idx);
56 	print_name_offset(m, timer);
57 	SEQ_printf(m, ", ");
58 	print_name_offset(m, timer->function);
59 	SEQ_printf(m, ", S:%02lx", timer->state);
60 #ifdef CONFIG_TIMER_STATS
61 	SEQ_printf(m, ", ");
62 	print_name_offset(m, timer->start_site);
63 	memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
64 	tmp[TASK_COMM_LEN] = 0;
65 	SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
66 #endif
67 	SEQ_printf(m, "\n");
68 	SEQ_printf(m, " # expires at %Lu nsecs [in %Ld nsecs]\n",
69 		(unsigned long long)ktime_to_ns(timer->expires),
70 		(long long)(ktime_to_ns(timer->expires) - now));
71 }
72 
73 static void
74 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
75 		    u64 now)
76 {
77 	struct hrtimer *timer, tmp;
78 	unsigned long next = 0, i;
79 	struct rb_node *curr;
80 	unsigned long flags;
81 
82 next_one:
83 	i = 0;
84 	spin_lock_irqsave(&base->cpu_base->lock, flags);
85 
86 	curr = base->first;
87 	/*
88 	 * Crude but we have to do this O(N*N) thing, because
89 	 * we have to unlock the base when printing:
90 	 */
91 	while (curr && i < next) {
92 		curr = rb_next(curr);
93 		i++;
94 	}
95 
96 	if (curr) {
97 
98 		timer = rb_entry(curr, struct hrtimer, node);
99 		tmp = *timer;
100 		spin_unlock_irqrestore(&base->cpu_base->lock, flags);
101 
102 		print_timer(m, &tmp, i, now);
103 		next++;
104 		goto next_one;
105 	}
106 	spin_unlock_irqrestore(&base->cpu_base->lock, flags);
107 }
108 
109 static void
110 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
111 {
112 	SEQ_printf(m, "  .index:      %d\n",
113 			base->index);
114 	SEQ_printf(m, "  .resolution: %Lu nsecs\n",
115 			(unsigned long long)ktime_to_ns(base->resolution));
116 	SEQ_printf(m,   "  .get_time:   ");
117 	print_name_offset(m, base->get_time);
118 	SEQ_printf(m,   "\n");
119 #ifdef CONFIG_HIGH_RES_TIMERS
120 	SEQ_printf(m, "  .offset:     %Lu nsecs\n",
121 		   (unsigned long long) ktime_to_ns(base->offset));
122 #endif
123 	SEQ_printf(m,   "active timers:\n");
124 	print_active_timers(m, base, now);
125 }
126 
127 static void print_cpu(struct seq_file *m, int cpu, u64 now)
128 {
129 	struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
130 	int i;
131 
132 	SEQ_printf(m, "\n");
133 	SEQ_printf(m, "cpu: %d\n", cpu);
134 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
135 		SEQ_printf(m, " clock %d:\n", i);
136 		print_base(m, cpu_base->clock_base + i, now);
137 	}
138 #define P(x) \
139 	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
140 		   (unsigned long long)(cpu_base->x))
141 #define P_ns(x) \
142 	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
143 		   (unsigned long long)(ktime_to_ns(cpu_base->x)))
144 
145 #ifdef CONFIG_HIGH_RES_TIMERS
146 	P_ns(expires_next);
147 	P(hres_active);
148 	P(nr_events);
149 #endif
150 #undef P
151 #undef P_ns
152 
153 #ifdef CONFIG_TICK_ONESHOT
154 # define P(x) \
155 	SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
156 		   (unsigned long long)(ts->x))
157 # define P_ns(x) \
158 	SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
159 		   (unsigned long long)(ktime_to_ns(ts->x)))
160 	{
161 		struct tick_sched *ts = tick_get_tick_sched(cpu);
162 		P(nohz_mode);
163 		P_ns(idle_tick);
164 		P(tick_stopped);
165 		P(idle_jiffies);
166 		P(idle_calls);
167 		P(idle_sleeps);
168 		P_ns(idle_entrytime);
169 		P_ns(idle_waketime);
170 		P_ns(idle_exittime);
171 		P_ns(idle_sleeptime);
172 		P(last_jiffies);
173 		P(next_jiffies);
174 		P_ns(idle_expires);
175 		SEQ_printf(m, "jiffies: %Lu\n",
176 			   (unsigned long long)jiffies);
177 	}
178 #endif
179 
180 #undef P
181 #undef P_ns
182 }
183 
184 #ifdef CONFIG_GENERIC_CLOCKEVENTS
185 static void
186 print_tickdevice(struct seq_file *m, struct tick_device *td)
187 {
188 	struct clock_event_device *dev = td->evtdev;
189 
190 	SEQ_printf(m, "\n");
191 	SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
192 
193 	SEQ_printf(m, "Clock Event Device: ");
194 	if (!dev) {
195 		SEQ_printf(m, "<NULL>\n");
196 		return;
197 	}
198 	SEQ_printf(m, "%s\n", dev->name);
199 	SEQ_printf(m, " max_delta_ns:   %lu\n", dev->max_delta_ns);
200 	SEQ_printf(m, " min_delta_ns:   %lu\n", dev->min_delta_ns);
201 	SEQ_printf(m, " mult:           %lu\n", dev->mult);
202 	SEQ_printf(m, " shift:          %d\n", dev->shift);
203 	SEQ_printf(m, " mode:           %d\n", dev->mode);
204 	SEQ_printf(m, " next_event:     %Ld nsecs\n",
205 		   (unsigned long long) ktime_to_ns(dev->next_event));
206 
207 	SEQ_printf(m, " set_next_event: ");
208 	print_name_offset(m, dev->set_next_event);
209 	SEQ_printf(m, "\n");
210 
211 	SEQ_printf(m, " set_mode:       ");
212 	print_name_offset(m, dev->set_mode);
213 	SEQ_printf(m, "\n");
214 
215 	SEQ_printf(m, " event_handler:  ");
216 	print_name_offset(m, dev->event_handler);
217 	SEQ_printf(m, "\n");
218 }
219 
220 static void timer_list_show_tickdevices(struct seq_file *m)
221 {
222 	int cpu;
223 
224 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
225 	print_tickdevice(m, tick_get_broadcast_device());
226 	SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
227 		   tick_get_broadcast_mask()->bits[0]);
228 #ifdef CONFIG_TICK_ONESHOT
229 	SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
230 		   tick_get_broadcast_oneshot_mask()->bits[0]);
231 #endif
232 	SEQ_printf(m, "\n");
233 #endif
234 	for_each_online_cpu(cpu)
235 		   print_tickdevice(m, tick_get_device(cpu));
236 	SEQ_printf(m, "\n");
237 }
238 #else
239 static void timer_list_show_tickdevices(struct seq_file *m) { }
240 #endif
241 
242 static int timer_list_show(struct seq_file *m, void *v)
243 {
244 	u64 now = ktime_to_ns(ktime_get());
245 	int cpu;
246 
247 	SEQ_printf(m, "Timer List Version: v0.3\n");
248 	SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
249 	SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
250 
251 	for_each_online_cpu(cpu)
252 		print_cpu(m, cpu, now);
253 
254 	SEQ_printf(m, "\n");
255 	timer_list_show_tickdevices(m);
256 
257 	return 0;
258 }
259 
260 void sysrq_timer_list_show(void)
261 {
262 	timer_list_show(NULL, NULL);
263 }
264 
265 static int timer_list_open(struct inode *inode, struct file *filp)
266 {
267 	return single_open(filp, timer_list_show, NULL);
268 }
269 
270 static struct file_operations timer_list_fops = {
271 	.open		= timer_list_open,
272 	.read		= seq_read,
273 	.llseek		= seq_lseek,
274 	.release	= single_release,
275 };
276 
277 static int __init init_timer_list_procfs(void)
278 {
279 	struct proc_dir_entry *pe;
280 
281 	pe = proc_create("timer_list", 0644, NULL, &timer_list_fops);
282 	if (!pe)
283 		return -ENOMEM;
284 	return 0;
285 }
286 __initcall(init_timer_list_procfs);
287