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 20 #include <linux/uaccess.h> 21 22 #include "tick-internal.h" 23 24 struct timer_list_iter { 25 int cpu; 26 bool second_pass; 27 u64 now; 28 }; 29 30 typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes); 31 32 /* 33 * This allows printing both to /proc/timer_list and 34 * to the console (on SysRq-Q): 35 */ 36 __printf(2, 3) 37 static void SEQ_printf(struct seq_file *m, const char *fmt, ...) 38 { 39 va_list args; 40 41 va_start(args, fmt); 42 43 if (m) 44 seq_vprintf(m, fmt, args); 45 else 46 vprintk(fmt, args); 47 48 va_end(args); 49 } 50 51 static void print_name_offset(struct seq_file *m, void *sym) 52 { 53 char symname[KSYM_NAME_LEN]; 54 55 if (lookup_symbol_name((unsigned long)sym, symname) < 0) 56 SEQ_printf(m, "<%pK>", sym); 57 else 58 SEQ_printf(m, "%s", symname); 59 } 60 61 static void 62 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer, 63 int idx, u64 now) 64 { 65 #ifdef CONFIG_TIMER_STATS 66 char tmp[TASK_COMM_LEN + 1]; 67 #endif 68 SEQ_printf(m, " #%d: ", idx); 69 print_name_offset(m, taddr); 70 SEQ_printf(m, ", "); 71 print_name_offset(m, timer->function); 72 SEQ_printf(m, ", S:%02x", timer->state); 73 #ifdef CONFIG_TIMER_STATS 74 SEQ_printf(m, ", "); 75 print_name_offset(m, timer->start_site); 76 memcpy(tmp, timer->start_comm, TASK_COMM_LEN); 77 tmp[TASK_COMM_LEN] = 0; 78 SEQ_printf(m, ", %s/%d", tmp, timer->start_pid); 79 #endif 80 SEQ_printf(m, "\n"); 81 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n", 82 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)), 83 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), 84 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now), 85 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); 86 } 87 88 static void 89 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, 90 u64 now) 91 { 92 struct hrtimer *timer, tmp; 93 unsigned long next = 0, i; 94 struct timerqueue_node *curr; 95 unsigned long flags; 96 97 next_one: 98 i = 0; 99 raw_spin_lock_irqsave(&base->cpu_base->lock, flags); 100 101 curr = timerqueue_getnext(&base->active); 102 /* 103 * Crude but we have to do this O(N*N) thing, because 104 * we have to unlock the base when printing: 105 */ 106 while (curr && i < next) { 107 curr = timerqueue_iterate_next(curr); 108 i++; 109 } 110 111 if (curr) { 112 113 timer = container_of(curr, struct hrtimer, node); 114 tmp = *timer; 115 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 116 117 print_timer(m, timer, &tmp, i, now); 118 next++; 119 goto next_one; 120 } 121 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 122 } 123 124 static void 125 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) 126 { 127 SEQ_printf(m, " .base: %pK\n", base); 128 SEQ_printf(m, " .index: %d\n", base->index); 129 130 SEQ_printf(m, " .resolution: %u nsecs\n", (unsigned) hrtimer_resolution); 131 132 SEQ_printf(m, " .get_time: "); 133 print_name_offset(m, base->get_time); 134 SEQ_printf(m, "\n"); 135 #ifdef CONFIG_HIGH_RES_TIMERS 136 SEQ_printf(m, " .offset: %Lu nsecs\n", 137 (unsigned long long) ktime_to_ns(base->offset)); 138 #endif 139 SEQ_printf(m, "active timers:\n"); 140 print_active_timers(m, base, now + ktime_to_ns(base->offset)); 141 } 142 143 static void print_cpu(struct seq_file *m, int cpu, u64 now) 144 { 145 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 146 int i; 147 148 SEQ_printf(m, "cpu: %d\n", cpu); 149 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 150 SEQ_printf(m, " clock %d:\n", i); 151 print_base(m, cpu_base->clock_base + i, now); 152 } 153 #define P(x) \ 154 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 155 (unsigned long long)(cpu_base->x)) 156 #define P_ns(x) \ 157 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 158 (unsigned long long)(ktime_to_ns(cpu_base->x))) 159 160 #ifdef CONFIG_HIGH_RES_TIMERS 161 P_ns(expires_next); 162 P(hres_active); 163 P(nr_events); 164 P(nr_retries); 165 P(nr_hangs); 166 P(max_hang_time); 167 #endif 168 #undef P 169 #undef P_ns 170 171 #ifdef CONFIG_TICK_ONESHOT 172 # define P(x) \ 173 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 174 (unsigned long long)(ts->x)) 175 # define P_ns(x) \ 176 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 177 (unsigned long long)(ktime_to_ns(ts->x))) 178 { 179 struct tick_sched *ts = tick_get_tick_sched(cpu); 180 P(nohz_mode); 181 P_ns(last_tick); 182 P(tick_stopped); 183 P(idle_jiffies); 184 P(idle_calls); 185 P(idle_sleeps); 186 P_ns(idle_entrytime); 187 P_ns(idle_waketime); 188 P_ns(idle_exittime); 189 P_ns(idle_sleeptime); 190 P_ns(iowait_sleeptime); 191 P(last_jiffies); 192 P(next_timer); 193 P_ns(idle_expires); 194 SEQ_printf(m, "jiffies: %Lu\n", 195 (unsigned long long)jiffies); 196 } 197 #endif 198 199 #undef P 200 #undef P_ns 201 SEQ_printf(m, "\n"); 202 } 203 204 #ifdef CONFIG_GENERIC_CLOCKEVENTS 205 static void 206 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 207 { 208 struct clock_event_device *dev = td->evtdev; 209 210 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 211 if (cpu < 0) 212 SEQ_printf(m, "Broadcast device\n"); 213 else 214 SEQ_printf(m, "Per CPU device: %d\n", cpu); 215 216 SEQ_printf(m, "Clock Event Device: "); 217 if (!dev) { 218 SEQ_printf(m, "<NULL>\n"); 219 return; 220 } 221 SEQ_printf(m, "%s\n", dev->name); 222 SEQ_printf(m, " max_delta_ns: %llu\n", 223 (unsigned long long) dev->max_delta_ns); 224 SEQ_printf(m, " min_delta_ns: %llu\n", 225 (unsigned long long) dev->min_delta_ns); 226 SEQ_printf(m, " mult: %u\n", dev->mult); 227 SEQ_printf(m, " shift: %u\n", dev->shift); 228 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 229 SEQ_printf(m, " next_event: %Ld nsecs\n", 230 (unsigned long long) ktime_to_ns(dev->next_event)); 231 232 SEQ_printf(m, " set_next_event: "); 233 print_name_offset(m, dev->set_next_event); 234 SEQ_printf(m, "\n"); 235 236 if (dev->set_state_shutdown) { 237 SEQ_printf(m, " shutdown: "); 238 print_name_offset(m, dev->set_state_shutdown); 239 SEQ_printf(m, "\n"); 240 } 241 242 if (dev->set_state_periodic) { 243 SEQ_printf(m, " periodic: "); 244 print_name_offset(m, dev->set_state_periodic); 245 SEQ_printf(m, "\n"); 246 } 247 248 if (dev->set_state_oneshot) { 249 SEQ_printf(m, " oneshot: "); 250 print_name_offset(m, dev->set_state_oneshot); 251 SEQ_printf(m, "\n"); 252 } 253 254 if (dev->set_state_oneshot_stopped) { 255 SEQ_printf(m, " oneshot stopped: "); 256 print_name_offset(m, dev->set_state_oneshot_stopped); 257 SEQ_printf(m, "\n"); 258 } 259 260 if (dev->tick_resume) { 261 SEQ_printf(m, " resume: "); 262 print_name_offset(m, dev->tick_resume); 263 SEQ_printf(m, "\n"); 264 } 265 266 SEQ_printf(m, " event_handler: "); 267 print_name_offset(m, dev->event_handler); 268 SEQ_printf(m, "\n"); 269 SEQ_printf(m, " retries: %lu\n", dev->retries); 270 SEQ_printf(m, "\n"); 271 } 272 273 static void timer_list_show_tickdevices_header(struct seq_file *m) 274 { 275 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 276 print_tickdevice(m, tick_get_broadcast_device(), -1); 277 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 278 cpumask_pr_args(tick_get_broadcast_mask())); 279 #ifdef CONFIG_TICK_ONESHOT 280 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 281 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 282 #endif 283 SEQ_printf(m, "\n"); 284 #endif 285 } 286 #endif 287 288 static inline void timer_list_header(struct seq_file *m, u64 now) 289 { 290 SEQ_printf(m, "Timer List Version: v0.8\n"); 291 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 292 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 293 SEQ_printf(m, "\n"); 294 } 295 296 static int timer_list_show(struct seq_file *m, void *v) 297 { 298 struct timer_list_iter *iter = v; 299 300 if (iter->cpu == -1 && !iter->second_pass) 301 timer_list_header(m, iter->now); 302 else if (!iter->second_pass) 303 print_cpu(m, iter->cpu, iter->now); 304 #ifdef CONFIG_GENERIC_CLOCKEVENTS 305 else if (iter->cpu == -1 && iter->second_pass) 306 timer_list_show_tickdevices_header(m); 307 else 308 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 309 #endif 310 return 0; 311 } 312 313 void sysrq_timer_list_show(void) 314 { 315 u64 now = ktime_to_ns(ktime_get()); 316 int cpu; 317 318 timer_list_header(NULL, now); 319 320 for_each_online_cpu(cpu) 321 print_cpu(NULL, cpu, now); 322 323 #ifdef CONFIG_GENERIC_CLOCKEVENTS 324 timer_list_show_tickdevices_header(NULL); 325 for_each_online_cpu(cpu) 326 print_tickdevice(NULL, tick_get_device(cpu), cpu); 327 #endif 328 return; 329 } 330 331 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 332 { 333 for (; offset; offset--) { 334 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 335 if (iter->cpu >= nr_cpu_ids) { 336 #ifdef CONFIG_GENERIC_CLOCKEVENTS 337 if (!iter->second_pass) { 338 iter->cpu = -1; 339 iter->second_pass = true; 340 } else 341 return NULL; 342 #else 343 return NULL; 344 #endif 345 } 346 } 347 return iter; 348 } 349 350 static void *timer_list_start(struct seq_file *file, loff_t *offset) 351 { 352 struct timer_list_iter *iter = file->private; 353 354 if (!*offset) 355 iter->now = ktime_to_ns(ktime_get()); 356 iter->cpu = -1; 357 iter->second_pass = false; 358 return move_iter(iter, *offset); 359 } 360 361 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 362 { 363 struct timer_list_iter *iter = file->private; 364 ++*offset; 365 return move_iter(iter, 1); 366 } 367 368 static void timer_list_stop(struct seq_file *seq, void *v) 369 { 370 } 371 372 static const struct seq_operations timer_list_sops = { 373 .start = timer_list_start, 374 .next = timer_list_next, 375 .stop = timer_list_stop, 376 .show = timer_list_show, 377 }; 378 379 static int timer_list_open(struct inode *inode, struct file *filp) 380 { 381 return seq_open_private(filp, &timer_list_sops, 382 sizeof(struct timer_list_iter)); 383 } 384 385 static const struct file_operations timer_list_fops = { 386 .open = timer_list_open, 387 .read = seq_read, 388 .llseek = seq_lseek, 389 .release = seq_release_private, 390 }; 391 392 static int __init init_timer_list_procfs(void) 393 { 394 struct proc_dir_entry *pe; 395 396 pe = proc_create("timer_list", 0444, NULL, &timer_list_fops); 397 if (!pe) 398 return -ENOMEM; 399 return 0; 400 } 401 __initcall(init_timer_list_procfs); 402