1// SPDX-License-Identifier: GPL-2.0
2/*
3 * List pending timers
4 *
5 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
6 */
7
8#include <linux/proc_fs.h>
9#include <linux/module.h>
10#include <linux/spinlock.h>
11#include <linux/sched.h>
12#include <linux/seq_file.h>
13#include <linux/kallsyms.h>
14#include <linux/nmi.h>
15
16#include <linux/uaccess.h>
17
18#include "tick-internal.h"
19
20struct timer_list_iter {
21 int cpu;
22 bool second_pass;
23 u64 now;
24};
25
26/*
27 * This allows printing both to /proc/timer_list and
28 * to the console (on SysRq-Q):
29 */
30__printf(2, 3)
31static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
32{
33 va_list args;
34
35 va_start(args, fmt);
36
37 if (m)
38 seq_vprintf(m, fmt, args);
39 else
40 vprintk(fmt, args);
41
42 va_end(args);
43}
44
45static void
46print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
47 int idx, u64 now)
48{
49 SEQ_printf(m, fmt: " #%d: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(timer, function));
50 SEQ_printf(m, fmt: ", S:%02x", timer->state);
51 SEQ_printf(m, fmt: "\n");
52 SEQ_printf(m, fmt: " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
53 (unsigned long long)ktime_to_ns(kt: hrtimer_get_softexpires(timer)),
54 (unsigned long long)ktime_to_ns(kt: hrtimer_get_expires(timer)),
55 (long long)(ktime_to_ns(kt: hrtimer_get_softexpires(timer)) - now),
56 (long long)(ktime_to_ns(kt: hrtimer_get_expires(timer)) - now));
57}
58
59static void
60print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
61 u64 now)
62{
63 struct hrtimer *timer, tmp;
64 unsigned long next = 0, i;
65 struct timerqueue_node *curr;
66 unsigned long flags;
67
68next_one:
69 i = 0;
70
71 touch_nmi_watchdog();
72
73 raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
74
75 curr = timerqueue_getnext(head: &base->active);
76 /*
77 * Crude but we have to do this O(N*N) thing, because
78 * we have to unlock the base when printing:
79 */
80 while (curr && i < next) {
81 curr = timerqueue_iterate_next(node: curr);
82 i++;
83 }
84
85 if (curr) {
86
87 timer = container_of(curr, struct hrtimer, node);
88 tmp = *timer;
89 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
90
91 print_timer(m, taddr: timer, timer: &tmp, idx: i, now);
92 next++;
93 goto next_one;
94 }
95 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
96}
97
98static void
99print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
100{
101 SEQ_printf(m, fmt: " .base: %p\n", base);
102 SEQ_printf(m, fmt: " .index: %d\n", base->index);
103
104 SEQ_printf(m, fmt: " .resolution: %u nsecs\n", hrtimer_resolution);
105
106 SEQ_printf(m, fmt: " .get_time: %ps\n", base->get_time);
107#ifdef CONFIG_HIGH_RES_TIMERS
108 SEQ_printf(m, fmt: " .offset: %Lu nsecs\n",
109 (unsigned long long) ktime_to_ns(kt: base->offset));
110#endif
111 SEQ_printf(m, fmt: "active timers:\n");
112 print_active_timers(m, base, now: now + ktime_to_ns(kt: base->offset));
113}
114
115static void print_cpu(struct seq_file *m, int cpu, u64 now)
116{
117 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
118 int i;
119
120 SEQ_printf(m, fmt: "cpu: %d\n", cpu);
121 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
122 SEQ_printf(m, fmt: " clock %d:\n", i);
123 print_base(m, base: cpu_base->clock_base + i, now);
124 }
125#define P(x) \
126 SEQ_printf(m, " .%-15s: %Lu\n", #x, \
127 (unsigned long long)(cpu_base->x))
128#define P_ns(x) \
129 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
130 (unsigned long long)(ktime_to_ns(cpu_base->x)))
131
132#ifdef CONFIG_HIGH_RES_TIMERS
133 P_ns(expires_next);
134 P(hres_active);
135 P(nr_events);
136 P(nr_retries);
137 P(nr_hangs);
138 P(max_hang_time);
139#endif
140#undef P
141#undef P_ns
142
143#ifdef CONFIG_TICK_ONESHOT
144# define P(x) \
145 SEQ_printf(m, " .%-15s: %Lu\n", #x, \
146 (unsigned long long)(ts->x))
147# define P_ns(x) \
148 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
149 (unsigned long long)(ktime_to_ns(ts->x)))
150# define P_flag(x, f) \
151 SEQ_printf(m, " .%-15s: %d\n", #x, !!(ts->flags & (f)))
152
153 {
154 struct tick_sched *ts = tick_get_tick_sched(cpu);
155 P_flag(nohz, TS_FLAG_NOHZ);
156 P_flag(highres, TS_FLAG_HIGHRES);
157 P_ns(last_tick);
158 P_flag(tick_stopped, TS_FLAG_STOPPED);
159 P(idle_jiffies);
160 P(idle_calls);
161 P(idle_sleeps);
162 P_ns(idle_entrytime);
163 P_ns(idle_waketime);
164 P_ns(idle_exittime);
165 P_ns(idle_sleeptime);
166 P_ns(iowait_sleeptime);
167 P(last_jiffies);
168 P(next_timer);
169 P_ns(idle_expires);
170 SEQ_printf(m, fmt: "jiffies: %Lu\n",
171 (unsigned long long)jiffies);
172 }
173#endif
174
175#undef P
176#undef P_ns
177 SEQ_printf(m, fmt: "\n");
178}
179
180#ifdef CONFIG_GENERIC_CLOCKEVENTS
181static void
182print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
183{
184 struct clock_event_device *dev = td->evtdev;
185
186 touch_nmi_watchdog();
187
188 SEQ_printf(m, fmt: "Tick Device: mode: %d\n", td->mode);
189 if (cpu < 0)
190 SEQ_printf(m, fmt: "Broadcast device\n");
191 else
192 SEQ_printf(m, fmt: "Per CPU device: %d\n", cpu);
193
194 SEQ_printf(m, fmt: "Clock Event Device: ");
195 if (!dev) {
196 SEQ_printf(m, fmt: "<NULL>\n");
197 return;
198 }
199 SEQ_printf(m, fmt: "%s\n", dev->name);
200 SEQ_printf(m, fmt: " max_delta_ns: %llu\n",
201 (unsigned long long) dev->max_delta_ns);
202 SEQ_printf(m, fmt: " min_delta_ns: %llu\n",
203 (unsigned long long) dev->min_delta_ns);
204 SEQ_printf(m, fmt: " mult: %u\n", dev->mult);
205 SEQ_printf(m, fmt: " shift: %u\n", dev->shift);
206 SEQ_printf(m, fmt: " mode: %d\n", clockevent_get_state(dev));
207 SEQ_printf(m, fmt: " next_event: %Ld nsecs\n",
208 (unsigned long long) ktime_to_ns(kt: dev->next_event));
209
210 SEQ_printf(m, fmt: " set_next_event: %ps\n", dev->set_next_event);
211
212 if (dev->set_state_shutdown)
213 SEQ_printf(m, fmt: " shutdown: %ps\n",
214 dev->set_state_shutdown);
215
216 if (dev->set_state_periodic)
217 SEQ_printf(m, fmt: " periodic: %ps\n",
218 dev->set_state_periodic);
219
220 if (dev->set_state_oneshot)
221 SEQ_printf(m, fmt: " oneshot: %ps\n",
222 dev->set_state_oneshot);
223
224 if (dev->set_state_oneshot_stopped)
225 SEQ_printf(m, fmt: " oneshot stopped: %ps\n",
226 dev->set_state_oneshot_stopped);
227
228 if (dev->tick_resume)
229 SEQ_printf(m, fmt: " resume: %ps\n",
230 dev->tick_resume);
231
232 SEQ_printf(m, fmt: " event_handler: %ps\n", dev->event_handler);
233 SEQ_printf(m, fmt: "\n");
234 SEQ_printf(m, fmt: " retries: %lu\n", dev->retries);
235
236#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
237 if (cpu >= 0) {
238 const struct clock_event_device *wd = tick_get_wakeup_device(cpu);
239
240 SEQ_printf(m, fmt: "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
241 }
242#endif
243 SEQ_printf(m, fmt: "\n");
244}
245
246static void timer_list_show_tickdevices_header(struct seq_file *m)
247{
248#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
249 print_tickdevice(m, td: tick_get_broadcast_device(), cpu: -1);
250 SEQ_printf(m, fmt: "tick_broadcast_mask: %*pb\n",
251 cpumask_pr_args(tick_get_broadcast_mask()));
252#ifdef CONFIG_TICK_ONESHOT
253 SEQ_printf(m, fmt: "tick_broadcast_oneshot_mask: %*pb\n",
254 cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
255#endif
256 SEQ_printf(m, fmt: "\n");
257#endif
258}
259#endif
260
261static inline void timer_list_header(struct seq_file *m, u64 now)
262{
263 SEQ_printf(m, fmt: "Timer List Version: v0.10\n");
264 SEQ_printf(m, fmt: "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
265 SEQ_printf(m, fmt: "now at %Ld nsecs\n", (unsigned long long)now);
266 SEQ_printf(m, fmt: "\n");
267}
268
269void sysrq_timer_list_show(void)
270{
271 u64 now = ktime_to_ns(kt: ktime_get());
272 int cpu;
273
274 timer_list_header(NULL, now);
275
276 for_each_online_cpu(cpu)
277 print_cpu(NULL, cpu, now);
278
279#ifdef CONFIG_GENERIC_CLOCKEVENTS
280 timer_list_show_tickdevices_header(NULL);
281 for_each_online_cpu(cpu)
282 print_tickdevice(NULL, td: tick_get_device(cpu), cpu);
283#endif
284 return;
285}
286
287#ifdef CONFIG_PROC_FS
288static int timer_list_show(struct seq_file *m, void *v)
289{
290 struct timer_list_iter *iter = v;
291
292 if (iter->cpu == -1 && !iter->second_pass)
293 timer_list_header(m, now: iter->now);
294 else if (!iter->second_pass)
295 print_cpu(m, cpu: iter->cpu, now: iter->now);
296#ifdef CONFIG_GENERIC_CLOCKEVENTS
297 else if (iter->cpu == -1 && iter->second_pass)
298 timer_list_show_tickdevices_header(m);
299 else
300 print_tickdevice(m, td: tick_get_device(cpu: iter->cpu), cpu: iter->cpu);
301#endif
302 return 0;
303}
304
305static void *move_iter(struct timer_list_iter *iter, loff_t offset)
306{
307 for (; offset; offset--) {
308 iter->cpu = cpumask_next(n: iter->cpu, cpu_online_mask);
309 if (iter->cpu >= nr_cpu_ids) {
310#ifdef CONFIG_GENERIC_CLOCKEVENTS
311 if (!iter->second_pass) {
312 iter->cpu = -1;
313 iter->second_pass = true;
314 } else
315 return NULL;
316#else
317 return NULL;
318#endif
319 }
320 }
321 return iter;
322}
323
324static void *timer_list_start(struct seq_file *file, loff_t *offset)
325{
326 struct timer_list_iter *iter = file->private;
327
328 if (!*offset)
329 iter->now = ktime_to_ns(kt: ktime_get());
330 iter->cpu = -1;
331 iter->second_pass = false;
332 return move_iter(iter, offset: *offset);
333}
334
335static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
336{
337 struct timer_list_iter *iter = file->private;
338 ++*offset;
339 return move_iter(iter, offset: 1);
340}
341
342static void timer_list_stop(struct seq_file *seq, void *v)
343{
344}
345
346static const struct seq_operations timer_list_sops = {
347 .start = timer_list_start,
348 .next = timer_list_next,
349 .stop = timer_list_stop,
350 .show = timer_list_show,
351};
352
353static int __init init_timer_list_procfs(void)
354{
355 struct proc_dir_entry *pe;
356
357 pe = proc_create_seq_private(name: "timer_list", mode: 0400, NULL, ops: &timer_list_sops,
358 state_size: sizeof(struct timer_list_iter), NULL);
359 if (!pe)
360 return -ENOMEM;
361 return 0;
362}
363__initcall(init_timer_list_procfs);
364#endif
365

source code of linux/kernel/time/timer_list.c

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