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