[PATCH] Add debugging feature /proc/timer_list
[linux-2.6.git] / 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         unsigned long addr = (unsigned long)sym;
42         char namebuf[KSYM_NAME_LEN+1];
43         unsigned long size, offset;
44         const char *sym_name;
45         char *modname;
46
47         sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
48         if (sym_name)
49                 SEQ_printf(m, "%s", sym_name);
50         else
51                 SEQ_printf(m, "<%p>", sym);
52 }
53
54 static void
55 print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now)
56 {
57 #ifdef CONFIG_TIMER_STATS
58         char tmp[TASK_COMM_LEN + 1];
59 #endif
60         SEQ_printf(m, " #%d: ", idx);
61         print_name_offset(m, timer);
62         SEQ_printf(m, ", ");
63         print_name_offset(m, timer->function);
64         SEQ_printf(m, ", S:%02lx", timer->state);
65 #ifdef CONFIG_TIMER_STATS
66         SEQ_printf(m, ", ");
67         print_name_offset(m, timer->start_site);
68         memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
69         tmp[TASK_COMM_LEN] = 0;
70         SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
71 #endif
72         SEQ_printf(m, "\n");
73         SEQ_printf(m, " # expires at %Ld nsecs [in %Ld nsecs]\n",
74                 (unsigned long long)ktime_to_ns(timer->expires),
75                 (unsigned long long)(ktime_to_ns(timer->expires) - now));
76 }
77
78 static void
79 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
80                     u64 now)
81 {
82         struct hrtimer *timer, tmp;
83         unsigned long next = 0, i;
84         struct rb_node *curr;
85         unsigned long flags;
86
87 next_one:
88         i = 0;
89         spin_lock_irqsave(&base->cpu_base->lock, flags);
90
91         curr = base->first;
92         /*
93          * Crude but we have to do this O(N*N) thing, because
94          * we have to unlock the base when printing:
95          */
96         while (curr && i < next) {
97                 curr = rb_next(curr);
98                 i++;
99         }
100
101         if (curr) {
102
103                 timer = rb_entry(curr, struct hrtimer, node);
104                 tmp = *timer;
105                 spin_unlock_irqrestore(&base->cpu_base->lock, flags);
106
107                 print_timer(m, &tmp, i, now);
108                 next++;
109                 goto next_one;
110         }
111         spin_unlock_irqrestore(&base->cpu_base->lock, flags);
112 }
113
114 static void
115 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
116 {
117         SEQ_printf(m, "  .index:      %d\n",
118                         base->index);
119         SEQ_printf(m, "  .resolution: %Ld nsecs\n",
120                         (unsigned long long)ktime_to_ns(base->resolution));
121         SEQ_printf(m,   "  .get_time:   ");
122         print_name_offset(m, base->get_time);
123         SEQ_printf(m,   "\n");
124 #ifdef CONFIG_HIGH_RES_TIMERS
125         SEQ_printf(m, "  .offset:     %Ld nsecs\n",
126                         ktime_to_ns(base->offset));
127 #endif
128         SEQ_printf(m,   "active timers:\n");
129         print_active_timers(m, base, now);
130 }
131
132 static void print_cpu(struct seq_file *m, int cpu, u64 now)
133 {
134         struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
135         int i;
136
137         SEQ_printf(m, "\ncpu: %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: %Ld\n", #x, (u64)(cpu_base->x))
144 #define P_ns(x) \
145         SEQ_printf(m, "  .%-15s: %Ld nsecs\n", #x, \
146                 (u64)(ktime_to_ns(cpu_base->x)))
147
148 #ifdef CONFIG_HIGH_RES_TIMERS
149         P_ns(expires_next);
150         P(hres_active);
151         P(nr_events);
152 #endif
153 #undef P
154 #undef P_ns
155
156 #ifdef CONFIG_TICK_ONESHOT
157 # define P(x) \
158         SEQ_printf(m, "  .%-15s: %Ld\n", #x, (u64)(ts->x))
159 # define P_ns(x) \
160         SEQ_printf(m, "  .%-15s: %Ld nsecs\n", #x, \
161                 (u64)(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_sleeptime);
172                 P(last_jiffies);
173                 P(next_jiffies);
174                 P_ns(idle_expires);
175                 SEQ_printf(m, "jiffies: %Ld\n", (u64)jiffies);
176         }
177 #endif
178
179 #undef P
180 #undef P_ns
181 }
182
183 #ifdef CONFIG_GENERIC_CLOCKEVENTS
184 static void
185 print_tickdevice(struct seq_file *m, struct tick_device *td)
186 {
187         struct clock_event_device *dev = td->evtdev;
188
189         SEQ_printf(m, "\nTick Device: mode:     %d\n", td->mode);
190
191         SEQ_printf(m, "Clock Event Device: ");
192         if (!dev) {
193                 SEQ_printf(m, "<NULL>\n");
194                 return;
195         }
196         SEQ_printf(m, "%s\n", dev->name);
197         SEQ_printf(m, " max_delta_ns:   %ld\n", dev->max_delta_ns);
198         SEQ_printf(m, " min_delta_ns:   %ld\n", dev->min_delta_ns);
199         SEQ_printf(m, " mult:           %ld\n", dev->mult);
200         SEQ_printf(m, " shift:          %d\n", dev->shift);
201         SEQ_printf(m, " mode:           %d\n", dev->mode);
202         SEQ_printf(m, " next_event:     %Ld nsecs\n",
203                    (unsigned long long) ktime_to_ns(dev->next_event));
204
205         SEQ_printf(m, " set_next_event: ");
206         print_name_offset(m, dev->set_next_event);
207         SEQ_printf(m, "\n");
208
209         SEQ_printf(m, " set_mode:       ");
210         print_name_offset(m, dev->set_mode);
211         SEQ_printf(m, "\n");
212
213         SEQ_printf(m, " event_handler:  ");
214         print_name_offset(m, dev->event_handler);
215         SEQ_printf(m, "\n");
216 }
217
218 static void timer_list_show_tickdevices(struct seq_file *m)
219 {
220         int cpu;
221
222 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
223         print_tickdevice(m, tick_get_broadcast_device());
224         SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
225                    tick_get_broadcast_mask()->bits[0]);
226 #ifdef CONFIG_TICK_ONESHOT
227         SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
228                    tick_get_broadcast_oneshot_mask()->bits[0]);
229 #endif
230         SEQ_printf(m, "\n");
231 #endif
232         for_each_online_cpu(cpu)
233                    print_tickdevice(m, tick_get_device(cpu));
234         SEQ_printf(m, "\n");
235 }
236 #else
237 static void timer_list_show_tickdevices(struct seq_file *m) { }
238 #endif
239
240 static int timer_list_show(struct seq_file *m, void *v)
241 {
242         u64 now = ktime_to_ns(ktime_get());
243         int cpu;
244
245         SEQ_printf(m, "Timer List Version: v0.3\n");
246         SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
247         SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
248
249         for_each_online_cpu(cpu)
250                 print_cpu(m, cpu, now);
251
252         SEQ_printf(m, "\n");
253         timer_list_show_tickdevices(m);
254
255         return 0;
256 }
257
258 void sysrq_timer_list_show(void)
259 {
260         timer_list_show(NULL, NULL);
261 }
262
263 static int timer_list_open(struct inode *inode, struct file *filp)
264 {
265         return single_open(filp, timer_list_show, NULL);
266 }
267
268 static struct file_operations timer_list_fops = {
269         .open           = timer_list_open,
270         .read           = seq_read,
271         .llseek         = seq_lseek,
272         .release        = seq_release,
273 };
274
275 static int __init init_timer_list_procfs(void)
276 {
277         struct proc_dir_entry *pe;
278
279         pe = create_proc_entry("timer_list", 0644, NULL);
280         if (!pe)
281                 return -ENOMEM;
282
283         pe->proc_fops = &timer_list_fops;
284
285         return 0;
286 }
287 __initcall(init_timer_list_procfs);