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