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: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(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: %p\n", base); 102 SEQ_printf(m, " .index: %d\n", base->index); 103 104 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution); 105 #ifdef CONFIG_HIGH_RES_TIMERS 106 SEQ_printf(m, " .offset: %Lu nsecs\n", 107 (unsigned long long) ktime_to_ns(base->offset)); 108 #endif 109 SEQ_printf(m, "active timers:\n"); 110 print_active_timers(m, base, now + ktime_to_ns(base->offset)); 111 } 112 113 static void print_cpu(struct seq_file *m, int cpu, u64 now) 114 { 115 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 116 int i; 117 118 SEQ_printf(m, "cpu: %d\n", cpu); 119 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 120 SEQ_printf(m, " clock %d:\n", i); 121 print_base(m, cpu_base->clock_base + i, now); 122 } 123 #define P(x) \ 124 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 125 (unsigned long long)(cpu_base->x)) 126 #define P_ns(x) \ 127 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 128 (unsigned long long)(ktime_to_ns(cpu_base->x))) 129 130 #ifdef CONFIG_HIGH_RES_TIMERS 131 P_ns(expires_next); 132 P(hres_active); 133 P(nr_events); 134 P(nr_retries); 135 P(nr_hangs); 136 P(max_hang_time); 137 #endif 138 #undef P 139 #undef P_ns 140 141 #ifdef CONFIG_TICK_ONESHOT 142 # define P(x) \ 143 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 144 (unsigned long long)(ts->x)) 145 # define P_ns(x) \ 146 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 147 (unsigned long long)(ktime_to_ns(ts->x))) 148 # define P_flag(x, f) \ 149 SEQ_printf(m, " .%-15s: %d\n", #x, !!(ts->flags & (f))) 150 151 { 152 struct tick_sched *ts = tick_get_tick_sched(cpu); 153 P_flag(nohz, TS_FLAG_NOHZ); 154 P_flag(highres, TS_FLAG_HIGHRES); 155 P_ns(last_tick); 156 P_flag(tick_stopped, TS_FLAG_STOPPED); 157 P(idle_jiffies); 158 P(idle_calls); 159 P(idle_sleeps); 160 P_ns(idle_entrytime); 161 P_ns(idle_waketime); 162 P_ns(idle_exittime); 163 P_ns(idle_sleeptime); 164 P_ns(iowait_sleeptime); 165 P(last_jiffies); 166 P(next_timer); 167 P_ns(idle_expires); 168 SEQ_printf(m, "jiffies: %Lu\n", 169 (unsigned long long)jiffies); 170 } 171 #endif 172 173 #undef P 174 #undef P_ns 175 SEQ_printf(m, "\n"); 176 } 177 178 #ifdef CONFIG_GENERIC_CLOCKEVENTS 179 static void 180 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 181 { 182 struct clock_event_device *dev = td->evtdev; 183 184 touch_nmi_watchdog(); 185 186 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 187 if (cpu < 0) 188 SEQ_printf(m, "Broadcast device\n"); 189 else 190 SEQ_printf(m, "Per CPU device: %d\n", cpu); 191 192 SEQ_printf(m, "Clock Event Device: "); 193 if (!dev) { 194 SEQ_printf(m, "<NULL>\n"); 195 return; 196 } 197 SEQ_printf(m, "%s\n", dev->name); 198 SEQ_printf(m, " max_delta_ns: %llu\n", 199 (unsigned long long) dev->max_delta_ns); 200 SEQ_printf(m, " min_delta_ns: %llu\n", 201 (unsigned long long) dev->min_delta_ns); 202 SEQ_printf(m, " mult: %u\n", dev->mult); 203 SEQ_printf(m, " shift: %u\n", dev->shift); 204 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 205 SEQ_printf(m, " next_event: %Ld nsecs\n", 206 (unsigned long long) ktime_to_ns(dev->next_event)); 207 208 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event); 209 210 if (dev->set_state_shutdown) 211 SEQ_printf(m, " shutdown: %ps\n", 212 dev->set_state_shutdown); 213 214 if (dev->set_state_periodic) 215 SEQ_printf(m, " periodic: %ps\n", 216 dev->set_state_periodic); 217 218 if (dev->set_state_oneshot) 219 SEQ_printf(m, " oneshot: %ps\n", 220 dev->set_state_oneshot); 221 222 if (dev->set_state_oneshot_stopped) 223 SEQ_printf(m, " oneshot stopped: %ps\n", 224 dev->set_state_oneshot_stopped); 225 226 if (dev->tick_resume) 227 SEQ_printf(m, " resume: %ps\n", 228 dev->tick_resume); 229 230 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler); 231 SEQ_printf(m, "\n"); 232 SEQ_printf(m, " retries: %lu\n", dev->retries); 233 234 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 235 if (cpu >= 0) { 236 const struct clock_event_device *wd = tick_get_wakeup_device(cpu); 237 238 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>"); 239 } 240 #endif 241 SEQ_printf(m, "\n"); 242 } 243 244 static void timer_list_show_tickdevices_header(struct seq_file *m) 245 { 246 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 247 print_tickdevice(m, tick_get_broadcast_device(), -1); 248 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 249 cpumask_pr_args(tick_get_broadcast_mask())); 250 #ifdef CONFIG_TICK_ONESHOT 251 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 252 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 253 #endif 254 SEQ_printf(m, "\n"); 255 #endif 256 } 257 #endif 258 259 static inline void timer_list_header(struct seq_file *m, u64 now) 260 { 261 SEQ_printf(m, "Timer List Version: v0.10\n"); 262 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 263 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 264 SEQ_printf(m, "\n"); 265 } 266 267 void sysrq_timer_list_show(void) 268 { 269 u64 now = ktime_to_ns(ktime_get()); 270 int cpu; 271 272 timer_list_header(NULL, now); 273 274 for_each_online_cpu(cpu) 275 print_cpu(NULL, cpu, now); 276 277 #ifdef CONFIG_GENERIC_CLOCKEVENTS 278 timer_list_show_tickdevices_header(NULL); 279 for_each_online_cpu(cpu) 280 print_tickdevice(NULL, tick_get_device(cpu), cpu); 281 #endif 282 return; 283 } 284 285 #ifdef CONFIG_PROC_FS 286 static int timer_list_show(struct seq_file *m, void *v) 287 { 288 struct timer_list_iter *iter = v; 289 290 if (iter->cpu == -1 && !iter->second_pass) 291 timer_list_header(m, iter->now); 292 else if (!iter->second_pass) 293 print_cpu(m, iter->cpu, iter->now); 294 #ifdef CONFIG_GENERIC_CLOCKEVENTS 295 else if (iter->cpu == -1 && iter->second_pass) 296 timer_list_show_tickdevices_header(m); 297 else 298 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 299 #endif 300 return 0; 301 } 302 303 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 304 { 305 for (; offset; offset--) { 306 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 307 if (iter->cpu >= nr_cpu_ids) { 308 #ifdef CONFIG_GENERIC_CLOCKEVENTS 309 if (!iter->second_pass) { 310 iter->cpu = -1; 311 iter->second_pass = true; 312 } else 313 return NULL; 314 #else 315 return NULL; 316 #endif 317 } 318 } 319 return iter; 320 } 321 322 static void *timer_list_start(struct seq_file *file, loff_t *offset) 323 { 324 struct timer_list_iter *iter = file->private; 325 326 if (!*offset) 327 iter->now = ktime_to_ns(ktime_get()); 328 iter->cpu = -1; 329 iter->second_pass = false; 330 return move_iter(iter, *offset); 331 } 332 333 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 334 { 335 struct timer_list_iter *iter = file->private; 336 ++*offset; 337 return move_iter(iter, 1); 338 } 339 340 static void timer_list_stop(struct seq_file *seq, void *v) 341 { 342 } 343 344 static const struct seq_operations timer_list_sops = { 345 .start = timer_list_start, 346 .next = timer_list_next, 347 .stop = timer_list_stop, 348 .show = timer_list_show, 349 }; 350 351 static int __init init_timer_list_procfs(void) 352 { 353 struct proc_dir_entry *pe; 354 355 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, 356 sizeof(struct timer_list_iter), NULL); 357 if (!pe) 358 return -ENOMEM; 359 return 0; 360 } 361 __initcall(init_timer_list_procfs); 362 #endif 363