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 *timer, int idx, u64 now)
  51 {
  52 #ifdef CONFIG_TIMER_STATS
  53         char tmp[TASK_COMM_LEN + 1];
  54 #endif
  55         SEQ_printf(m, " #%d: ", idx);
  56         print_name_offset(m, timer);
  57         SEQ_printf(m, ", ");
  58         print_name_offset(m, timer->function);
  59         SEQ_printf(m, ", S:%02lx", timer->state);
  60 #ifdef CONFIG_TIMER_STATS
  61         SEQ_printf(m, ", ");
  62         print_name_offset(m, timer->start_site);
  63         memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
  64         tmp[TASK_COMM_LEN] = 0;
  65         SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
  66 #endif
  67         SEQ_printf(m, "\n");
  68         SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
  69                 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
  70                 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
  71                 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
  72                 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
  73 }
  74
  75 static void
  76 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
  77                     u64 now)
  78 {
  79         struct hrtimer *timer, tmp;
  80         unsigned long next = 0, i;
  81         struct rb_node *curr;
  82         unsigned long flags;
  83
  84 next_one:
  85         i = 0;
  86         spin_lock_irqsave(&base->cpu_base->lock, flags);
  87
  88         curr = base->first;
  89         /*
  90          * Crude but we have to do this O(N*N) thing, because
  91          * we have to unlock the base when printing:
  92          */
  93         while (curr && i < next) {
  94                 curr = rb_next(curr);
  95                 i++;
  96         }
  97
  98         if (curr) {
  99
 100                 timer = rb_entry(curr, struct hrtimer, node);
 101                 tmp = *timer;
 102                 spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 103
 104                 print_timer(m, &tmp, i, now);
 105                 next++;
 106                 goto next_one;
 107         }
 108         spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 109 }
 110
 111 static void
 112 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
 113 {
 114         SEQ_printf(m, "  .index:      %d\n",
 115                         base->index);
 116         SEQ_printf(m, "  .resolution: %Lu nsecs\n",
 117                         (unsigned long long)ktime_to_ns(base->resolution));
 118         SEQ_printf(m,   "  .get_time:   ");
 119         print_name_offset(m, base->get_time);
 120         SEQ_printf(m,   "\n");
 121 #ifdef CONFIG_HIGH_RES_TIMERS
 122         SEQ_printf(m, "  .offset:     %Lu nsecs\n",
 123                    (unsigned long long) ktime_to_ns(base->offset));
 124 #endif
 125         SEQ_printf(m,   "active timers:\n");
 126         print_active_timers(m, base, now);
 127 }
 128
 129 static void print_cpu(struct seq_file *m, int cpu, u64 now)
 130 {
 131         struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
 132         int i;
 133
 134         SEQ_printf(m, "\n");
 135         SEQ_printf(m, "cpu: %d\n", cpu);
 136         for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
 137                 SEQ_printf(m, " clock %d:\n", i);
 138                 print_base(m, cpu_base->clock_base + i, now);
 139         }
 140 #define P(x) \
 141         SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 142                    (unsigned long long)(cpu_base->x))
 143 #define P_ns(x) \
 144         SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 145                    (unsigned long long)(ktime_to_ns(cpu_base->x)))
 146
 147 #ifdef CONFIG_HIGH_RES_TIMERS
 148         P_ns(expires_next);
 149         P(hres_active);
 150         P(nr_events);
 151 #endif
 152 #undef P
 153 #undef P_ns
 154
 155 #ifdef CONFIG_TICK_ONESHOT
 156 # define P(x) \
 157         SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 158                    (unsigned long long)(ts->x))
 159 # define P_ns(x) \
 160         SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 161                    (unsigned long long)(ktime_to_ns(ts->x)))
 162         {
 163                 struct tick_sched *ts = tick_get_tick_sched(cpu);
 164                 P(nohz_mode);
 165                 P_ns(idle_tick);
 166                 P(tick_stopped);
 167                 P(idle_jiffies);
 168                 P(idle_calls);
 169                 P(idle_sleeps);
 170                 P_ns(idle_entrytime);
 171                 P_ns(idle_waketime);
 172                 P_ns(idle_exittime);
 173                 P_ns(idle_sleeptime);
 174                 P(last_jiffies);
 175                 P(next_jiffies);
 176                 P_ns(idle_expires);
 177                 SEQ_printf(m, "jiffies: %Lu\n",
 178                            (unsigned long long)jiffies);
 179         }
 180 #endif
 181
 182 #undef P
 183 #undef P_ns
 184 }
 185
 186 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 187 static void
 188 print_tickdevice(struct seq_file *m, struct tick_device *td)
 189 {
 190         struct clock_event_device *dev = td->evtdev;
 191
 192         SEQ_printf(m, "\n");
 193         SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
 194
 195         SEQ_printf(m, "Clock Event Device: ");
 196         if (!dev) {
 197                 SEQ_printf(m, "<NULL>\n");
 198                 return;
 199         }
 200         SEQ_printf(m, "%s\n", dev->name);
 201         SEQ_printf(m, " max_delta_ns:   %lu\n", dev->max_delta_ns);
 202         SEQ_printf(m, " min_delta_ns:   %lu\n", dev->min_delta_ns);
 203         SEQ_printf(m, " mult:           %lu\n", dev->mult);
 204         SEQ_printf(m, " shift:          %d\n", dev->shift);
 205         SEQ_printf(m, " mode:           %d\n", dev->mode);
 206         SEQ_printf(m, " next_event:     %Ld nsecs\n",
 207                    (unsigned long long) ktime_to_ns(dev->next_event));
 208
 209         SEQ_printf(m, " set_next_event: ");
 210         print_name_offset(m, dev->set_next_event);
 211         SEQ_printf(m, "\n");
 212
 213         SEQ_printf(m, " set_mode:       ");
 214         print_name_offset(m, dev->set_mode);
 215         SEQ_printf(m, "\n");
 216
 217         SEQ_printf(m, " event_handler:  ");
 218         print_name_offset(m, dev->event_handler);
 219         SEQ_printf(m, "\n");
 220 }
 221
 222 static void timer_list_show_tickdevices(struct seq_file *m)
 223 {
 224         int cpu;
 225
 226 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 227         print_tickdevice(m, tick_get_broadcast_device());
 228         SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
 229                    tick_get_broadcast_mask()->bits[0]);
 230 #ifdef CONFIG_TICK_ONESHOT
 231         SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
 232                    tick_get_broadcast_oneshot_mask()->bits[0]);
 233 #endif
 234         SEQ_printf(m, "\n");
 235 #endif
 236         for_each_online_cpu(cpu)
 237                    print_tickdevice(m, tick_get_device(cpu));
 238         SEQ_printf(m, "\n");
 239 }
 240 #else
 241 static void timer_list_show_tickdevices(struct seq_file *m) { }
 242 #endif
 243
 244 static int timer_list_show(struct seq_file *m, void *v)
 245 {
 246         u64 now = ktime_to_ns(ktime_get());
 247         int cpu;
 248
 249         SEQ_printf(m, "Timer List Version: v0.3\n");
 250         SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
 251         SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
 252
 253         for_each_online_cpu(cpu)
 254                 print_cpu(m, cpu, now);
 255
 256         SEQ_printf(m, "\n");
 257         timer_list_show_tickdevices(m);
 258
 259         return 0;
 260 }
 261
 262 void sysrq_timer_list_show(void)
 263 {
 264         timer_list_show(NULL, NULL);
 265 }
 266
 267 static int timer_list_open(struct inode *inode, struct file *filp)
 268 {
 269         return single_open(filp, timer_list_show, NULL);
 270 }
 271
 272 static struct file_operations timer_list_fops = {
 273         .open           = timer_list_open,
 274         .read           = seq_read,
 275         .llseek         = seq_lseek,
 276         .release        = single_release,
 277 };
 278
 279 static int __init init_timer_list_procfs(void)
 280 {
 281         struct proc_dir_entry *pe;
 282
 283         pe = proc_create("timer_list", 0644, NULL, &timer_list_fops);
 284         if (!pe)
 285                 return -ENOMEM;
 286         return 0;
 287 }
 288 __initcall(init_timer_list_procfs);