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