linux/kernel/time/timer_list.c
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   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
  23typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
  24
  25DECLARE_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
  39static 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, "<%pK>", sym);
  45        else
  46                SEQ_printf(m, "%s", symname);
  47}
  48
  49static void
  50print_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
  76static void
  77print_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 timerqueue_node *curr;
  83        unsigned long flags;
  84
  85next_one:
  86        i = 0;
  87        raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
  88
  89        curr = timerqueue_getnext(&base->active);
  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 = timerqueue_iterate_next(curr);
  96                i++;
  97        }
  98
  99        if (curr) {
 100
 101                timer = container_of(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
 112static void
 113print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
 114{
 115        SEQ_printf(m, "  .base:       %pK\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
 131static 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(last_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_ns(iowait_sleeptime);
 180                P(last_jiffies);
 181                P(next_jiffies);
 182                P_ns(idle_expires);
 183                SEQ_printf(m, "jiffies: %Lu\n",
 184                           (unsigned long long)jiffies);
 185        }
 186#endif
 187
 188#undef P
 189#undef P_ns
 190}
 191
 192#ifdef CONFIG_GENERIC_CLOCKEVENTS
 193static void
 194print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
 195{
 196        struct clock_event_device *dev = td->evtdev;
 197
 198        SEQ_printf(m, "\n");
 199        SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
 200        if (cpu < 0)
 201                SEQ_printf(m, "Broadcast device\n");
 202        else
 203                SEQ_printf(m, "Per CPU device: %d\n", cpu);
 204
 205        SEQ_printf(m, "Clock Event Device: ");
 206        if (!dev) {
 207                SEQ_printf(m, "<NULL>\n");
 208                return;
 209        }
 210        SEQ_printf(m, "%s\n", dev->name);
 211        SEQ_printf(m, " max_delta_ns:   %llu\n",
 212                   (unsigned long long) dev->max_delta_ns);
 213        SEQ_printf(m, " min_delta_ns:   %llu\n",
 214                   (unsigned long long) dev->min_delta_ns);
 215        SEQ_printf(m, " mult:           %u\n", dev->mult);
 216        SEQ_printf(m, " shift:          %u\n", dev->shift);
 217        SEQ_printf(m, " mode:           %d\n", dev->mode);
 218        SEQ_printf(m, " next_event:     %Ld nsecs\n",
 219                   (unsigned long long) ktime_to_ns(dev->next_event));
 220
 221        SEQ_printf(m, " set_next_event: ");
 222        print_name_offset(m, dev->set_next_event);
 223        SEQ_printf(m, "\n");
 224
 225        SEQ_printf(m, " set_mode:       ");
 226        print_name_offset(m, dev->set_mode);
 227        SEQ_printf(m, "\n");
 228
 229        SEQ_printf(m, " event_handler:  ");
 230        print_name_offset(m, dev->event_handler);
 231        SEQ_printf(m, "\n");
 232        SEQ_printf(m, " retries:        %lu\n", dev->retries);
 233}
 234
 235static void timer_list_show_tickdevices(struct seq_file *m)
 236{
 237        int cpu;
 238
 239#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 240        print_tickdevice(m, tick_get_broadcast_device(), -1);
 241        SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
 242                   cpumask_bits(tick_get_broadcast_mask())[0]);
 243#ifdef CONFIG_TICK_ONESHOT
 244        SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
 245                   cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
 246#endif
 247        SEQ_printf(m, "\n");
 248#endif
 249        for_each_online_cpu(cpu)
 250                print_tickdevice(m, tick_get_device(cpu), cpu);
 251        SEQ_printf(m, "\n");
 252}
 253#else
 254static void timer_list_show_tickdevices(struct seq_file *m) { }
 255#endif
 256
 257static int timer_list_show(struct seq_file *m, void *v)
 258{
 259        u64 now = ktime_to_ns(ktime_get());
 260        int cpu;
 261
 262        SEQ_printf(m, "Timer List Version: v0.7\n");
 263        SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
 264        SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
 265
 266        for_each_online_cpu(cpu)
 267                print_cpu(m, cpu, now);
 268
 269        SEQ_printf(m, "\n");
 270        timer_list_show_tickdevices(m);
 271
 272        return 0;
 273}
 274
 275void sysrq_timer_list_show(void)
 276{
 277        timer_list_show(NULL, NULL);
 278}
 279
 280static int timer_list_open(struct inode *inode, struct file *filp)
 281{
 282        return single_open(filp, timer_list_show, NULL);
 283}
 284
 285static const struct file_operations timer_list_fops = {
 286        .open           = timer_list_open,
 287        .read           = seq_read,
 288        .llseek         = seq_lseek,
 289        .release        = single_release,
 290};
 291
 292static int __init init_timer_list_procfs(void)
 293{
 294        struct proc_dir_entry *pe;
 295
 296        pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
 297        if (!pe)
 298                return -ENOMEM;
 299        return 0;
 300}
 301__initcall(init_timer_list_procfs);
 302
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