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/nmi.h> 20 21 #include <linux/uaccess.h> 22 23 #include "tick-internal.h" 24 25 struct timer_list_iter { 26 int cpu; 27 bool second_pass; 28 u64 now; 29 }; 30 31 typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes); 32 33 /* 34 * This allows printing both to /proc/timer_list and 35 * to the console (on SysRq-Q): 36 */ 37 __printf(2, 3) 38 static void SEQ_printf(struct seq_file *m, const char *fmt, ...) 39 { 40 va_list args; 41 42 va_start(args, fmt); 43 44 if (m) 45 seq_vprintf(m, fmt, args); 46 else 47 vprintk(fmt, args); 48 49 va_end(args); 50 } 51 52 static void print_name_offset(struct seq_file *m, void *sym) 53 { 54 char symname[KSYM_NAME_LEN]; 55 56 if (lookup_symbol_name((unsigned long)sym, symname) < 0) 57 SEQ_printf(m, "<%pK>", sym); 58 else 59 SEQ_printf(m, "%s", symname); 60 } 61 62 static void 63 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer, 64 int idx, u64 now) 65 { 66 SEQ_printf(m, " #%d: ", idx); 67 print_name_offset(m, taddr); 68 SEQ_printf(m, ", "); 69 print_name_offset(m, timer->function); 70 SEQ_printf(m, ", S:%02x", timer->state); 71 SEQ_printf(m, "\n"); 72 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n", 73 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)), 74 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), 75 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now), 76 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); 77 } 78 79 static void 80 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, 81 u64 now) 82 { 83 struct hrtimer *timer, tmp; 84 unsigned long next = 0, i; 85 struct timerqueue_node *curr; 86 unsigned long flags; 87 88 next_one: 89 i = 0; 90 91 touch_nmi_watchdog(); 92 93 raw_spin_lock_irqsave(&base->cpu_base->lock, flags); 94 95 curr = timerqueue_getnext(&base->active); 96 /* 97 * Crude but we have to do this O(N*N) thing, because 98 * we have to unlock the base when printing: 99 */ 100 while (curr && i < next) { 101 curr = timerqueue_iterate_next(curr); 102 i++; 103 } 104 105 if (curr) { 106 107 timer = container_of(curr, struct hrtimer, node); 108 tmp = *timer; 109 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 110 111 print_timer(m, timer, &tmp, i, now); 112 next++; 113 goto next_one; 114 } 115 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 116 } 117 118 static void 119 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) 120 { 121 SEQ_printf(m, " .base: %pK\n", base); 122 SEQ_printf(m, " .index: %d\n", base->index); 123 124 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution); 125 126 SEQ_printf(m, " .get_time: "); 127 print_name_offset(m, base->get_time); 128 SEQ_printf(m, "\n"); 129 #ifdef CONFIG_HIGH_RES_TIMERS 130 SEQ_printf(m, " .offset: %Lu nsecs\n", 131 (unsigned long long) ktime_to_ns(base->offset)); 132 #endif 133 SEQ_printf(m, "active timers:\n"); 134 print_active_timers(m, base, now + ktime_to_ns(base->offset)); 135 } 136 137 static void print_cpu(struct seq_file *m, int cpu, u64 now) 138 { 139 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 140 int i; 141 142 SEQ_printf(m, "cpu: %d\n", cpu); 143 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 144 SEQ_printf(m, " clock %d:\n", i); 145 print_base(m, cpu_base->clock_base + i, now); 146 } 147 #define P(x) \ 148 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 149 (unsigned long long)(cpu_base->x)) 150 #define P_ns(x) \ 151 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 152 (unsigned long long)(ktime_to_ns(cpu_base->x))) 153 154 #ifdef CONFIG_HIGH_RES_TIMERS 155 P_ns(expires_next); 156 P(hres_active); 157 P(nr_events); 158 P(nr_retries); 159 P(nr_hangs); 160 P(max_hang_time); 161 #endif 162 #undef P 163 #undef P_ns 164 165 #ifdef CONFIG_TICK_ONESHOT 166 # define P(x) \ 167 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 168 (unsigned long long)(ts->x)) 169 # define P_ns(x) \ 170 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 171 (unsigned long long)(ktime_to_ns(ts->x))) 172 { 173 struct tick_sched *ts = tick_get_tick_sched(cpu); 174 P(nohz_mode); 175 P_ns(last_tick); 176 P(tick_stopped); 177 P(idle_jiffies); 178 P(idle_calls); 179 P(idle_sleeps); 180 P_ns(idle_entrytime); 181 P_ns(idle_waketime); 182 P_ns(idle_exittime); 183 P_ns(idle_sleeptime); 184 P_ns(iowait_sleeptime); 185 P(last_jiffies); 186 P(next_timer); 187 P_ns(idle_expires); 188 SEQ_printf(m, "jiffies: %Lu\n", 189 (unsigned long long)jiffies); 190 } 191 #endif 192 193 #undef P 194 #undef P_ns 195 SEQ_printf(m, "\n"); 196 } 197 198 #ifdef CONFIG_GENERIC_CLOCKEVENTS 199 static void 200 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 201 { 202 struct clock_event_device *dev = td->evtdev; 203 204 touch_nmi_watchdog(); 205 206 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 207 if (cpu < 0) 208 SEQ_printf(m, "Broadcast device\n"); 209 else 210 SEQ_printf(m, "Per CPU device: %d\n", cpu); 211 212 SEQ_printf(m, "Clock Event Device: "); 213 if (!dev) { 214 SEQ_printf(m, "<NULL>\n"); 215 return; 216 } 217 SEQ_printf(m, "%s\n", dev->name); 218 SEQ_printf(m, " max_delta_ns: %llu\n", 219 (unsigned long long) dev->max_delta_ns); 220 SEQ_printf(m, " min_delta_ns: %llu\n", 221 (unsigned long long) dev->min_delta_ns); 222 SEQ_printf(m, " mult: %u\n", dev->mult); 223 SEQ_printf(m, " shift: %u\n", dev->shift); 224 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 225 SEQ_printf(m, " next_event: %Ld nsecs\n", 226 (unsigned long long) ktime_to_ns(dev->next_event)); 227 228 SEQ_printf(m, " set_next_event: "); 229 print_name_offset(m, dev->set_next_event); 230 SEQ_printf(m, "\n"); 231 232 if (dev->set_state_shutdown) { 233 SEQ_printf(m, " shutdown: "); 234 print_name_offset(m, dev->set_state_shutdown); 235 SEQ_printf(m, "\n"); 236 } 237 238 if (dev->set_state_periodic) { 239 SEQ_printf(m, " periodic: "); 240 print_name_offset(m, dev->set_state_periodic); 241 SEQ_printf(m, "\n"); 242 } 243 244 if (dev->set_state_oneshot) { 245 SEQ_printf(m, " oneshot: "); 246 print_name_offset(m, dev->set_state_oneshot); 247 SEQ_printf(m, "\n"); 248 } 249 250 if (dev->set_state_oneshot_stopped) { 251 SEQ_printf(m, " oneshot stopped: "); 252 print_name_offset(m, dev->set_state_oneshot_stopped); 253 SEQ_printf(m, "\n"); 254 } 255 256 if (dev->tick_resume) { 257 SEQ_printf(m, " resume: "); 258 print_name_offset(m, dev->tick_resume); 259 SEQ_printf(m, "\n"); 260 } 261 262 SEQ_printf(m, " event_handler: "); 263 print_name_offset(m, dev->event_handler); 264 SEQ_printf(m, "\n"); 265 SEQ_printf(m, " retries: %lu\n", dev->retries); 266 SEQ_printf(m, "\n"); 267 } 268 269 static void timer_list_show_tickdevices_header(struct seq_file *m) 270 { 271 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 272 print_tickdevice(m, tick_get_broadcast_device(), -1); 273 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 274 cpumask_pr_args(tick_get_broadcast_mask())); 275 #ifdef CONFIG_TICK_ONESHOT 276 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 277 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 278 #endif 279 SEQ_printf(m, "\n"); 280 #endif 281 } 282 #endif 283 284 static inline void timer_list_header(struct seq_file *m, u64 now) 285 { 286 SEQ_printf(m, "Timer List Version: v0.8\n"); 287 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 288 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 289 SEQ_printf(m, "\n"); 290 } 291 292 static int timer_list_show(struct seq_file *m, void *v) 293 { 294 struct timer_list_iter *iter = v; 295 296 if (iter->cpu == -1 && !iter->second_pass) 297 timer_list_header(m, iter->now); 298 else if (!iter->second_pass) 299 print_cpu(m, iter->cpu, iter->now); 300 #ifdef CONFIG_GENERIC_CLOCKEVENTS 301 else if (iter->cpu == -1 && iter->second_pass) 302 timer_list_show_tickdevices_header(m); 303 else 304 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 305 #endif 306 return 0; 307 } 308 309 void sysrq_timer_list_show(void) 310 { 311 u64 now = ktime_to_ns(ktime_get()); 312 int cpu; 313 314 timer_list_header(NULL, now); 315 316 for_each_online_cpu(cpu) 317 print_cpu(NULL, cpu, now); 318 319 #ifdef CONFIG_GENERIC_CLOCKEVENTS 320 timer_list_show_tickdevices_header(NULL); 321 for_each_online_cpu(cpu) 322 print_tickdevice(NULL, tick_get_device(cpu), cpu); 323 #endif 324 return; 325 } 326 327 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 328 { 329 for (; offset; offset--) { 330 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 331 if (iter->cpu >= nr_cpu_ids) { 332 #ifdef CONFIG_GENERIC_CLOCKEVENTS 333 if (!iter->second_pass) { 334 iter->cpu = -1; 335 iter->second_pass = true; 336 } else 337 return NULL; 338 #else 339 return NULL; 340 #endif 341 } 342 } 343 return iter; 344 } 345 346 static void *timer_list_start(struct seq_file *file, loff_t *offset) 347 { 348 struct timer_list_iter *iter = file->private; 349 350 if (!*offset) 351 iter->now = ktime_to_ns(ktime_get()); 352 iter->cpu = -1; 353 iter->second_pass = false; 354 return move_iter(iter, *offset); 355 } 356 357 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 358 { 359 struct timer_list_iter *iter = file->private; 360 ++*offset; 361 return move_iter(iter, 1); 362 } 363 364 static void timer_list_stop(struct seq_file *seq, void *v) 365 { 366 } 367 368 static const struct seq_operations timer_list_sops = { 369 .start = timer_list_start, 370 .next = timer_list_next, 371 .stop = timer_list_stop, 372 .show = timer_list_show, 373 }; 374 375 static int timer_list_open(struct inode *inode, struct file *filp) 376 { 377 return seq_open_private(filp, &timer_list_sops, 378 sizeof(struct timer_list_iter)); 379 } 380 381 static const struct file_operations timer_list_fops = { 382 .open = timer_list_open, 383 .read = seq_read, 384 .llseek = seq_lseek, 385 .release = seq_release_private, 386 }; 387 388 static int __init init_timer_list_procfs(void) 389 { 390 struct proc_dir_entry *pe; 391 392 pe = proc_create("timer_list", 0400, NULL, &timer_list_fops); 393 if (!pe) 394 return -ENOMEM; 395 return 0; 396 } 397 __initcall(init_timer_list_procfs); 398