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, "<%p>", 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 rb_node *curr;
  83        unsigned long flags;
  84
  85next_one:
  86        i = 0;
  87        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                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        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:       %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
 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#endif
 154#undef P
 155#undef P_ns
 156
 157#ifdef CONFIG_TICK_ONESHOT
 158# define P(x) \
 159        SEQ_printf(m, "  .%-15s: %Lu\n", #x, \
 160                   (unsigned long long)(ts->x))
 161# define P_ns(x) \
 162        SEQ_printf(m, "  .%-15s: %Lu nsecs\n", #x, \
 163                   (unsigned long long)(ktime_to_ns(ts->x)))
 164        {
 165                struct tick_sched *ts = tick_get_tick_sched(cpu);
 166                P(nohz_mode);
 167                P_ns(idle_tick);
 168                P(tick_stopped);
 169                P(idle_jiffies);
 170                P(idle_calls);
 171                P(idle_sleeps);
 172                P_ns(idle_entrytime);
 173                P_ns(idle_waketime);
 174                P_ns(idle_exittime);
 175                P_ns(idle_sleeptime);
 176                P(last_jiffies);
 177                P(next_jiffies);
 178                P_ns(idle_expires);
 179                SEQ_printf(m, "jiffies: %Lu\n",
 180                           (unsigned long long)jiffies);
 181        }
 182#endif
 183
 184#undef P
 185#undef P_ns
 186}
 187
 188#ifdef CONFIG_GENERIC_CLOCKEVENTS
 189static void
 190print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
 191{
 192        struct clock_event_device *dev = td->evtdev;
 193
 194        SEQ_printf(m, "\n");
 195        SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
 196        if (cpu < 0)
 197                SEQ_printf(m, "Broadcast device\n");
 198        else
 199                SEQ_printf(m, "Per CPU device: %d\n", cpu);
 200
 201        SEQ_printf(m, "Clock Event Device: ");
 202        if (!dev) {
 203                SEQ_printf(m, "<NULL>\n");
 204                return;
 205        }
 206        SEQ_printf(m, "%s\n", dev->name);
 207        SEQ_printf(m, " max_delta_ns:   %lu\n", dev->max_delta_ns);
 208        SEQ_printf(m, " min_delta_ns:   %lu\n", dev->min_delta_ns);
 209        SEQ_printf(m, " mult:           %lu\n", dev->mult);
 210        SEQ_printf(m, " shift:          %d\n", dev->shift);
 211        SEQ_printf(m, " mode:           %d\n", dev->mode);
 212        SEQ_printf(m, " next_event:     %Ld nsecs\n",
 213                   (unsigned long long) ktime_to_ns(dev->next_event));
 214
 215        SEQ_printf(m, " set_next_event: ");
 216        print_name_offset(m, dev->set_next_event);
 217        SEQ_printf(m, "\n");
 218
 219        SEQ_printf(m, " set_mode:       ");
 220        print_name_offset(m, dev->set_mode);
 221        SEQ_printf(m, "\n");
 222
 223        SEQ_printf(m, " event_handler:  ");
 224        print_name_offset(m, dev->event_handler);
 225        SEQ_printf(m, "\n");
 226}
 227
 228static void timer_list_show_tickdevices(struct seq_file *m)
 229{
 230        int cpu;
 231
 232#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 233        print_tickdevice(m, tick_get_broadcast_device(), -1);
 234        SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
 235                   tick_get_broadcast_mask()->bits[0]);
 236#ifdef CONFIG_TICK_ONESHOT
 237        SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
 238                   tick_get_broadcast_oneshot_mask()->bits[0]);
 239#endif
 240        SEQ_printf(m, "\n");
 241#endif
 242        for_each_online_cpu(cpu)
 243                print_tickdevice(m, tick_get_device(cpu), cpu);
 244        SEQ_printf(m, "\n");
 245}
 246#else
 247static void timer_list_show_tickdevices(struct seq_file *m) { }
 248#endif
 249
 250static int timer_list_show(struct seq_file *m, void *v)
 251{
 252        u64 now = ktime_to_ns(ktime_get());
 253        int cpu;
 254
 255        SEQ_printf(m, "Timer List Version: v0.4\n");
 256        SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
 257        SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
 258
 259        for_each_online_cpu(cpu)
 260                print_cpu(m, cpu, now);
 261
 262        SEQ_printf(m, "\n");
 263        timer_list_show_tickdevices(m);
 264
 265        return 0;
 266}
 267
 268void sysrq_timer_list_show(void)
 269{
 270        timer_list_show(NULL, NULL);
 271}
 272
 273static int timer_list_open(struct inode *inode, struct file *filp)
 274{
 275        return single_open(filp, timer_list_show, NULL);
 276}
 277
 278static const struct file_operations timer_list_fops = {
 279        .open           = timer_list_open,
 280        .read           = seq_read,
 281        .llseek         = seq_lseek,
 282        .release        = single_release,
 283};
 284
 285static int __init init_timer_list_procfs(void)
 286{
 287        struct proc_dir_entry *pe;
 288
 289        pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
 290        if (!pe)
 291                return -ENOMEM;
 292        return 0;
 293}
 294__initcall(init_timer_list_procfs);
 295