kernel/time/timer_list.c

   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/tick.h>
  20
  21 #include <asm/uaccess.h>
  22
  23 typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
  24
  25 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
  26
  27 /*
  28  * This allows printing both to /proc/timer_list and
  29  * to the console (on SysRq-Q):
  30  */
  31 #define SEQ_printf(m, x...)                     \
  32  do {                                           \
  33         if (m)                                  \
  34                 seq_printf(m, x);               \
  35         else                                    \
  36                 printk(x);                      \
  37  } while (0)
  38
  39 static void print_name_offset(struct seq_file *m, void *sym)
  40 {
  41         char symname[KSYM_NAME_LEN];
  42
  43         if (lookup_symbol_name((unsigned long)sym, symname) < 0)
  44                 SEQ_printf(m, "<%p>", sym);
  45         else
  46                 SEQ_printf(m, "%s", symname);
  47 }
  48
  49 static void
  50 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
  51             int idx, u64 now)
  52 {
  53 #ifdef CONFIG_TIMER_STATS
  54         char tmp[TASK_COMM_LEN + 1];
  55 #endif
  56         SEQ_printf(m, " #%d: ", idx);
  57         print_name_offset(m, taddr);
  58         SEQ_printf(m, ", ");
  59         print_name_offset(m, timer->function);
  60         SEQ_printf(m, ", S:%02lx", timer->state);
  61 #ifdef CONFIG_TIMER_STATS
  62         SEQ_printf(m, ", ");
  63         print_name_offset(m, timer->start_site);
  64         memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
  65         tmp[TASK_COMM_LEN] = 0;
  66         SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
  67 #endif
  68         SEQ_printf(m, "\n");
  69         SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
  70                 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
  71                 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
  72                 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
  73                 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
  74 }
  75
  76 static void
  77 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
  78                     u64 now)
  79 {
  80         struct hrtimer *timer, tmp;
  81         unsigned long next = 0, i;
  82         struct rb_node *curr;
  83         unsigned long flags;
  84
  85 next_one:
  86         i = 0;
  87         raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
  88
  89         curr = base->first;
  90         /*
  91          * Crude but we have to do this O(N*N) thing, because
  92          * we have to unlock the base when printing:
  93          */
  94         while (curr && i < next) {
  95                 curr = rb_next(curr);
  96                 i++;
  97         }
  98
  99         if (curr) {
 100
 101                 timer = rb_entry(curr, struct hrtimer, node);
 102                 tmp = *timer;
 103                 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 104
 105                 print_timer(m, timer, &tmp, i, now);
 106                 next++;
 107                 goto next_one;
 108         }
 109         raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 110 }
 111
 112 static void
 113 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
 114 {
 115         SEQ_printf(m, "  .base:       %p\n", base);
 116         SEQ_printf(m, "  .index:      %d\n",
 117                         base->index);
 118         SEQ_printf(m, "  .resolution: %Lu nsecs\n",
 119                         (unsigned long long)ktime_to_ns(base->resolution));
 120         SEQ_printf(m,   "  .get_time:   ");
 121         print_name_offset(m, base->get_time);
 122         SEQ_printf(m,   "\n");
 123 #ifdef CONFIG_HIGH_RES_TIMERS
 124         SEQ_printf(m, "  .offset:     %Lu nsecs\n",
 125                    (unsigned long long) ktime_to_ns(base->offset));
 126 #endif
 127         SEQ_printf(m,   "active timers:\n");
 128         print_active_timers(m, base, now);
 129 }
 130
 131 static void print_cpu(struct seq_file *m, int cpu, u64 now)
 132 {
 133         struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
 134         int i;
 135
 136         SEQ_printf(m, "\n");
 137         SEQ_printf(m, "cpu: %d\n", cpu);
 138         for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
 139                 SEQ_printf(m, " clock %d:\n", i);
 140                 print_base(m, cpu_base->clock_base + i, now);
 141         }
 142 #define P(x) \
 143         SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 144                    (unsigned long long)(cpu_base->x))
 145 #define P_ns(x) \
 146         SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 147                    (unsigned long long)(ktime_to_ns(cpu_base->x)))
 148
 149 #ifdef CONFIG_HIGH_RES_TIMERS
 150         P_ns(expires_next);
 151         P(hres_active);
 152         P(nr_events);
 153         P(nr_retries);
 154         P(nr_hangs);
 155         P_ns(max_hang_time);
 156 #endif
 157 #undef P
 158 #undef P_ns
 159
 160 #ifdef CONFIG_TICK_ONESHOT
 161 # define P(x) \
 162         SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 163                    (unsigned long long)(ts->x))
 164 # define P_ns(x) \
 165         SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 166                    (unsigned long long)(ktime_to_ns(ts->x)))
 167         {
 168                 struct tick_sched *ts = tick_get_tick_sched(cpu);
 169                 P(nohz_mode);
 170                 P_ns(idle_tick);
 171                 P(tick_stopped);
 172                 P(idle_jiffies);
 173                 P(idle_calls);
 174                 P(idle_sleeps);
 175                 P_ns(idle_entrytime);
 176                 P_ns(idle_waketime);
 177                 P_ns(idle_exittime);
 178                 P_ns(idle_sleeptime);
 179                 P(last_jiffies);
 180                 P(next_jiffies);
 181                 P_ns(idle_expires);
 182                 SEQ_printf(m, "jiffies: %Lu\n",
 183                            (unsigned long long)jiffies);
 184         }
 185 #endif
 186
 187 #undef P
 188 #undef P_ns
 189 }
 190
 191 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 192 static void
 193 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
 194 {
 195         struct clock_event_device *dev = td->evtdev;
 196
 197         SEQ_printf(m, "\n");
 198         SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
 199         if (cpu < 0)
 200                 SEQ_printf(m, "Broadcast device\n");
 201         else
 202                 SEQ_printf(m, "Per CPU device: %d\n", cpu);
 203
 204         SEQ_printf(m, "Clock Event Device: ");
 205         if (!dev) {
 206                 SEQ_printf(m, "<NULL>\n");
 207                 return;
 208         }
 209         SEQ_printf(m, "%s\n", dev->name);
 210         SEQ_printf(m, " max_delta_ns:   %llu\n",
 211                    (unsigned long long) dev->max_delta_ns);
 212         SEQ_printf(m, " min_delta_ns:   %llu\n",
 213                    (unsigned long long) dev->min_delta_ns);
 214         SEQ_printf(m, " mult:           %u\n", dev->mult);
 215         SEQ_printf(m, " shift:          %u\n", dev->shift);
 216         SEQ_printf(m, " mode:           %d\n", dev->mode);
 217         SEQ_printf(m, " next_event:     %Ld nsecs\n",
 218                    (unsigned long long) ktime_to_ns(dev->next_event));
 219
 220         SEQ_printf(m, " set_next_event: ");
 221         print_name_offset(m, dev->set_next_event);
 222         SEQ_printf(m, "\n");
 223
 224         SEQ_printf(m, " set_mode:       ");
 225         print_name_offset(m, dev->set_mode);
 226         SEQ_printf(m, "\n");
 227
 228         SEQ_printf(m, " event_handler:  ");
 229         print_name_offset(m, dev->event_handler);
 230         SEQ_printf(m, "\n");
 231 }
 232
 233 static void timer_list_show_tickdevices(struct seq_file *m)
 234 {
 235         int cpu;
 236
 237 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 238         print_tickdevice(m, tick_get_broadcast_device(), -1);
 239         SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
 240                    cpumask_bits(tick_get_broadcast_mask())[0]);
 241 #ifdef CONFIG_TICK_ONESHOT
 242         SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
 243                    cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
 244 #endif
 245         SEQ_printf(m, "\n");
 246 #endif
 247         for_each_online_cpu(cpu)
 248                 print_tickdevice(m, tick_get_device(cpu), cpu);
 249         SEQ_printf(m, "\n");
 250 }
 251 #else
 252 static void timer_list_show_tickdevices(struct seq_file *m) { }
 253 #endif
 254
 255 static int timer_list_show(struct seq_file *m, void *v)
 256 {
 257         u64 now = ktime_to_ns(ktime_get());
 258         int cpu;
 259
 260         SEQ_printf(m, "Timer List Version: v0.5\n");
 261         SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
 262         SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
 263
 264         for_each_online_cpu(cpu)
 265                 print_cpu(m, cpu, now);
 266
 267         SEQ_printf(m, "\n");
 268         timer_list_show_tickdevices(m);
 269
 270         return 0;
 271 }
 272
 273 void sysrq_timer_list_show(void)
 274 {
 275         timer_list_show(NULL, NULL);
 276 }
 277
 278 static int timer_list_open(struct inode *inode, struct file *filp)
 279 {
 280         return single_open(filp, timer_list_show, NULL);
 281 }
 282
 283 static const struct file_operations timer_list_fops = {
 284         .open           = timer_list_open,
 285         .read           = seq_read,
 286         .llseek         = seq_lseek,
 287         .release        = single_release,
 288 };
 289
 290 static int __init init_timer_list_procfs(void)
 291 {
 292         struct proc_dir_entry *pe;
 293
 294         pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
 295         if (!pe)
 296                 return -ENOMEM;
 297         return 0;
 298 }
 299 __initcall(init_timer_list_procfs);