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[mirror_ubuntu-jammy-kernel.git] / kernel / time / timer_list.c
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
20 struct 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)
31 static 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
45 static void
46 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
47 int idx, u64 now)
48 {
49 SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function);
50 SEQ_printf(m, ", S:%02x", timer->state);
51 SEQ_printf(m, "\n");
52 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
53 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
54 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
55 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
56 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
57 }
58
59 static void
60 print_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
68 next_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(&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(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, timer, &tmp, i, now);
92 next++;
93 goto next_one;
94 }
95 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
96 }
97
98 static void
99 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
100 {
101 SEQ_printf(m, " .base: %pK\n", base);
102 SEQ_printf(m, " .index: %d\n", base->index);
103
104 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution);
105
106 SEQ_printf(m, " .get_time: %ps\n", base->get_time);
107 #ifdef CONFIG_HIGH_RES_TIMERS
108 SEQ_printf(m, " .offset: %Lu nsecs\n",
109 (unsigned long long) ktime_to_ns(base->offset));
110 #endif
111 SEQ_printf(m, "active timers:\n");
112 print_active_timers(m, base, now + ktime_to_ns(base->offset));
113 }
114
115 static 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, "cpu: %d\n", cpu);
121 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
122 SEQ_printf(m, " clock %d:\n", i);
123 print_base(m, 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 {
151 struct tick_sched *ts = tick_get_tick_sched(cpu);
152 P(nohz_mode);
153 P_ns(last_tick);
154 P(tick_stopped);
155 P(idle_jiffies);
156 P(idle_calls);
157 P(idle_sleeps);
158 P_ns(idle_entrytime);
159 P_ns(idle_waketime);
160 P_ns(idle_exittime);
161 P_ns(idle_sleeptime);
162 P_ns(iowait_sleeptime);
163 P(last_jiffies);
164 P(next_timer);
165 P_ns(idle_expires);
166 SEQ_printf(m, "jiffies: %Lu\n",
167 (unsigned long long)jiffies);
168 }
169 #endif
170
171 #undef P
172 #undef P_ns
173 SEQ_printf(m, "\n");
174 }
175
176 #ifdef CONFIG_GENERIC_CLOCKEVENTS
177 static void
178 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
179 {
180 struct clock_event_device *dev = td->evtdev;
181
182 touch_nmi_watchdog();
183
184 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
185 if (cpu < 0)
186 SEQ_printf(m, "Broadcast device\n");
187 else
188 SEQ_printf(m, "Per CPU device: %d\n", cpu);
189
190 SEQ_printf(m, "Clock Event Device: ");
191 if (!dev) {
192 SEQ_printf(m, "<NULL>\n");
193 return;
194 }
195 SEQ_printf(m, "%s\n", dev->name);
196 SEQ_printf(m, " max_delta_ns: %llu\n",
197 (unsigned long long) dev->max_delta_ns);
198 SEQ_printf(m, " min_delta_ns: %llu\n",
199 (unsigned long long) dev->min_delta_ns);
200 SEQ_printf(m, " mult: %u\n", dev->mult);
201 SEQ_printf(m, " shift: %u\n", dev->shift);
202 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev));
203 SEQ_printf(m, " next_event: %Ld nsecs\n",
204 (unsigned long long) ktime_to_ns(dev->next_event));
205
206 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);
207
208 if (dev->set_state_shutdown)
209 SEQ_printf(m, " shutdown: %ps\n",
210 dev->set_state_shutdown);
211
212 if (dev->set_state_periodic)
213 SEQ_printf(m, " periodic: %ps\n",
214 dev->set_state_periodic);
215
216 if (dev->set_state_oneshot)
217 SEQ_printf(m, " oneshot: %ps\n",
218 dev->set_state_oneshot);
219
220 if (dev->set_state_oneshot_stopped)
221 SEQ_printf(m, " oneshot stopped: %ps\n",
222 dev->set_state_oneshot_stopped);
223
224 if (dev->tick_resume)
225 SEQ_printf(m, " resume: %ps\n",
226 dev->tick_resume);
227
228 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler);
229 SEQ_printf(m, "\n");
230 SEQ_printf(m, " retries: %lu\n", dev->retries);
231 SEQ_printf(m, "\n");
232 }
233
234 static void timer_list_show_tickdevices_header(struct seq_file *m)
235 {
236 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
237 print_tickdevice(m, tick_get_broadcast_device(), -1);
238 SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
239 cpumask_pr_args(tick_get_broadcast_mask()));
240 #ifdef CONFIG_TICK_ONESHOT
241 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
242 cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
243 #endif
244 SEQ_printf(m, "\n");
245 #endif
246 }
247 #endif
248
249 static inline void timer_list_header(struct seq_file *m, u64 now)
250 {
251 SEQ_printf(m, "Timer List Version: v0.8\n");
252 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
253 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
254 SEQ_printf(m, "\n");
255 }
256
257 void sysrq_timer_list_show(void)
258 {
259 u64 now = ktime_to_ns(ktime_get());
260 int cpu;
261
262 timer_list_header(NULL, now);
263
264 for_each_online_cpu(cpu)
265 print_cpu(NULL, cpu, now);
266
267 #ifdef CONFIG_GENERIC_CLOCKEVENTS
268 timer_list_show_tickdevices_header(NULL);
269 for_each_online_cpu(cpu)
270 print_tickdevice(NULL, tick_get_device(cpu), cpu);
271 #endif
272 return;
273 }
274
275 #ifdef CONFIG_PROC_FS
276 static int timer_list_show(struct seq_file *m, void *v)
277 {
278 struct timer_list_iter *iter = v;
279
280 if (iter->cpu == -1 && !iter->second_pass)
281 timer_list_header(m, iter->now);
282 else if (!iter->second_pass)
283 print_cpu(m, iter->cpu, iter->now);
284 #ifdef CONFIG_GENERIC_CLOCKEVENTS
285 else if (iter->cpu == -1 && iter->second_pass)
286 timer_list_show_tickdevices_header(m);
287 else
288 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
289 #endif
290 return 0;
291 }
292
293 static void *move_iter(struct timer_list_iter *iter, loff_t offset)
294 {
295 for (; offset; offset--) {
296 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
297 if (iter->cpu >= nr_cpu_ids) {
298 #ifdef CONFIG_GENERIC_CLOCKEVENTS
299 if (!iter->second_pass) {
300 iter->cpu = -1;
301 iter->second_pass = true;
302 } else
303 return NULL;
304 #else
305 return NULL;
306 #endif
307 }
308 }
309 return iter;
310 }
311
312 static void *timer_list_start(struct seq_file *file, loff_t *offset)
313 {
314 struct timer_list_iter *iter = file->private;
315
316 if (!*offset)
317 iter->now = ktime_to_ns(ktime_get());
318 iter->cpu = -1;
319 iter->second_pass = false;
320 return move_iter(iter, *offset);
321 }
322
323 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
324 {
325 struct timer_list_iter *iter = file->private;
326 ++*offset;
327 return move_iter(iter, 1);
328 }
329
330 static void timer_list_stop(struct seq_file *seq, void *v)
331 {
332 }
333
334 static const struct seq_operations timer_list_sops = {
335 .start = timer_list_start,
336 .next = timer_list_next,
337 .stop = timer_list_stop,
338 .show = timer_list_show,
339 };
340
341 static int __init init_timer_list_procfs(void)
342 {
343 struct proc_dir_entry *pe;
344
345 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
346 sizeof(struct timer_list_iter), NULL);
347 if (!pe)
348 return -ENOMEM;
349 return 0;
350 }
351 __initcall(init_timer_list_procfs);
352 #endif