Commit 289f480a authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[PATCH] Add debugging feature /proc/timer_list



add /proc/timer_list, which prints all currently pending (high-res) timers,
all clock-event sources and their parameters in a human-readable form.

Sample output:

Timer List Version: v0.1
HRTIMER_MAX_CLOCK_BASES: 2
now at 4246046273872 nsecs

cpu: 0
 clock 0:
  .index:      0
  .resolution: 1 nsecs
  .get_time:   ktime_get_real
  .offset:     1273998312645738432 nsecs
active timers:
 clock 1:
  .index:      1
  .resolution: 1 nsecs
  .get_time:   ktime_get
  .offset:     0 nsecs
active timers:
 #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_stop_sched_tick, swapper/0
 # expires at 4246432689566 nsecs [in 386415694 nsecs]
 #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, pcscd/2050
 # expires at 4247018194689 nsecs [in 971920817 nsecs]
 #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, irqbalance/1909
 # expires at 4247351358392 nsecs [in 1305084520 nsecs]
 #3: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, crond/2157
 # expires at 4249097614968 nsecs [in 3051341096 nsecs]
 #4: <f5a90ec8>, it_real_fn, do_setitimer, syslogd/1888
 # expires at 4251329900926 nsecs [in 5283627054 nsecs]
  .expires_next   : 4246432689566 nsecs
  .hres_active    : 1
  .check_clocks   : 0
  .nr_events      : 31306
  .idle_tick      : 4246020791890 nsecs
  .tick_stopped   : 1
  .idle_jiffies   : 986504
  .idle_calls     : 40700
  .idle_sleeps    : 36014
  .idle_entrytime : 4246019418883 nsecs
  .idle_sleeptime : 4178181972709 nsecs

cpu: 1
 clock 0:
  .index:      0
  .resolution: 1 nsecs
  .get_time:   ktime_get_real
  .offset:     1273998312645738432 nsecs
active timers:
 clock 1:
  .index:      1
  .resolution: 1 nsecs
  .get_time:   ktime_get
  .offset:     0 nsecs
active timers:
 #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_restart_sched_tick, swapper/0
 # expires at 4246050084568 nsecs [in 3810696 nsecs]
 #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, atd/2227
 # expires at 4261010635003 nsecs [in 14964361131 nsecs]
 #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, smartd/2332
 # expires at 5469485798970 nsecs [in 1223439525098 nsecs]
  .expires_next   : 4246050084568 nsecs
  .hres_active    : 1
  .check_clocks   : 0
  .nr_events      : 24043
  .idle_tick      : 4246046084568 nsecs
  .tick_stopped   : 0
  .idle_jiffies   : 986510
  .idle_calls     : 26360
  .idle_sleeps    : 22551
  .idle_entrytime : 4246043874339 nsecs
  .idle_sleeptime : 4170763761184 nsecs

tick_broadcast_mask: 00000003
event_broadcast_mask: 00000001

CPU#0's local event device:

Clock Event Device: lapic
 capabilities:   0000000e
 max_delta_ns:   807385544
 min_delta_ns:   1443
 mult:           44624025
 shift:          32
 set_next_event: lapic_next_event
 set_mode:       lapic_timer_setup
 event_handler:  hrtimer_interrupt
  .installed:  1
  .expires:    4246432689566 nsecs

CPU#1's local event device:

Clock Event Device: lapic
 capabilities:   0000000e
 max_delta_ns:   807385544
 min_delta_ns:   1443
 mult:           44624025
 shift:          32
 set_next_event: lapic_next_event
 set_mode:       lapic_timer_setup
 event_handler:  hrtimer_interrupt
  .installed:  1
  .expires:    4246050084568 nsecs

Clock Event Device: hpet
 capabilities:   00000007
 max_delta_ns:   2147483647
 min_delta_ns:   3352
 mult:           61496110
 shift:          32
 set_next_event: hpet_next_event
 set_mode:       hpet_set_mode
 event_handler:  handle_nextevt_broadcast
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 82f67cd9
......@@ -59,6 +59,7 @@ struct tick_sched {
extern void __init tick_init(void);
extern int tick_is_oneshot_available(void);
extern struct tick_device *tick_get_device(int cpu);
# ifdef CONFIG_HIGH_RES_TIMERS
extern int tick_init_highres(void);
......@@ -69,6 +70,16 @@ extern void tick_cancel_sched_timer(int cpu);
static inline void tick_cancel_sched_timer(int cpu) { }
# endif /* HIGHRES */
# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern struct tick_device *tick_get_broadcast_device(void);
extern cpumask_t *tick_get_broadcast_mask(void);
# ifdef CONFIG_TICK_ONESHOT
extern cpumask_t *tick_get_broadcast_oneshot_mask(void);
# endif
# endif /* BROADCAST */
# ifdef CONFIG_TICK_ONESHOT
extern void tick_clock_notify(void);
extern int tick_check_oneshot_change(int allow_nohz);
......
obj-y += ntp.o clocksource.o jiffies.o
obj-y += ntp.o clocksource.o jiffies.o timer_list.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS) += clockevents.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o
......
......@@ -31,6 +31,19 @@ struct tick_device tick_broadcast_device;
static cpumask_t tick_broadcast_mask;
static DEFINE_SPINLOCK(tick_broadcast_lock);
/*
* Debugging: see timer_list.c
*/
struct tick_device *tick_get_broadcast_device(void)
{
return &tick_broadcast_device;
}
cpumask_t *tick_get_broadcast_mask(void)
{
return &tick_broadcast_mask;
}
/*
* Start the device in periodic mode
*/
......@@ -275,6 +288,14 @@ void tick_shutdown_broadcast(unsigned int *cpup)
static cpumask_t tick_broadcast_oneshot_mask;
/*
* Debugging: see timer_list.c
*/
cpumask_t *tick_get_broadcast_oneshot_mask(void)
{
return &tick_broadcast_oneshot_mask;
}
static int tick_broadcast_set_event(ktime_t expires, int force)
{
struct clock_event_device *bc = tick_broadcast_device.evtdev;
......
......@@ -34,6 +34,14 @@ ktime_t tick_period;
static int tick_do_timer_cpu = -1;
DEFINE_SPINLOCK(tick_device_lock);
/*
* Debugging: see timer_list.c
*/
struct tick_device *tick_get_device(int cpu)
{
return &per_cpu(tick_cpu_device, cpu);
}
/**
* tick_is_oneshot_available - check for a oneshot capable event device
*/
......
......@@ -33,6 +33,11 @@ static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
*/
static ktime_t last_jiffies_update;
struct tick_sched *tick_get_tick_sched(int cpu)
{
return &per_cpu(tick_cpu_sched, cpu);
}
/*
* Must be called with interrupts disabled !
*/
......
/*
* kernel/time/timer_list.c
*
* List pending timers
*
* Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/tick.h>
#include <asm/uaccess.h>
typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
/*
* This allows printing both to /proc/timer_list and
* to the console (on SysRq-Q):
*/
#define SEQ_printf(m, x...) \
do { \
if (m) \
seq_printf(m, x); \
else \
printk(x); \
} while (0)
static void print_name_offset(struct seq_file *m, void *sym)
{
unsigned long addr = (unsigned long)sym;
char namebuf[KSYM_NAME_LEN+1];
unsigned long size, offset;
const char *sym_name;
char *modname;
sym_name = kallsyms_lookup(addr, &size, &offset, &modname, namebuf);
if (sym_name)
SEQ_printf(m, "%s", sym_name);
else
SEQ_printf(m, "<%p>", sym);
}
static void
print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now)
{
#ifdef CONFIG_TIMER_STATS
char tmp[TASK_COMM_LEN + 1];
#endif
SEQ_printf(m, " #%d: ", idx);
print_name_offset(m, timer);
SEQ_printf(m, ", ");
print_name_offset(m, timer->function);
SEQ_printf(m, ", S:%02lx", timer->state);
#ifdef CONFIG_TIMER_STATS
SEQ_printf(m, ", ");
print_name_offset(m, timer->start_site);
memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
tmp[TASK_COMM_LEN] = 0;
SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
#endif
SEQ_printf(m, "\n");
SEQ_printf(m, " # expires at %Ld nsecs [in %Ld nsecs]\n",
(unsigned long long)ktime_to_ns(timer->expires),
(unsigned long long)(ktime_to_ns(timer->expires) - now));
}
static void
print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
u64 now)
{
struct hrtimer *timer, tmp;
unsigned long next = 0, i;
struct rb_node *curr;
unsigned long flags;
next_one:
i = 0;
spin_lock_irqsave(&base->cpu_base->lock, flags);
curr = base->first;
/*
* Crude but we have to do this O(N*N) thing, because
* we have to unlock the base when printing:
*/
while (curr && i < next) {
curr = rb_next(curr);
i++;
}
if (curr) {
timer = rb_entry(curr, struct hrtimer, node);
tmp = *timer;
spin_unlock_irqrestore(&base->cpu_base->lock, flags);
print_timer(m, &tmp, i, now);
next++;
goto next_one;
}
spin_unlock_irqrestore(&base->cpu_base->lock, flags);
}
static void
print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
{
SEQ_printf(m, " .index: %d\n",
base->index);
SEQ_printf(m, " .resolution: %Ld nsecs\n",
(unsigned long long)ktime_to_ns(base->resolution));
SEQ_printf(m, " .get_time: ");
print_name_offset(m, base->get_time);
SEQ_printf(m, "\n");
#ifdef CONFIG_HIGH_RES_TIMERS
SEQ_printf(m, " .offset: %Ld nsecs\n",
ktime_to_ns(base->offset));
#endif
SEQ_printf(m, "active timers:\n");
print_active_timers(m, base, now);
}
static void print_cpu(struct seq_file *m, int cpu, u64 now)
{
struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
int i;
SEQ_printf(m, "\ncpu: %d\n", cpu);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
SEQ_printf(m, " clock %d:\n", i);
print_base(m, cpu_base->clock_base + i, now);
}
#define P(x) \
SEQ_printf(m, " .%-15s: %Ld\n", #x, (u64)(cpu_base->x))
#define P_ns(x) \
SEQ_printf(m, " .%-15s: %Ld nsecs\n", #x, \
(u64)(ktime_to_ns(cpu_base->x)))
#ifdef CONFIG_HIGH_RES_TIMERS
P_ns(expires_next);
P(hres_active);
P(nr_events);
#endif
#undef P
#undef P_ns
#ifdef CONFIG_TICK_ONESHOT
# define P(x) \
SEQ_printf(m, " .%-15s: %Ld\n", #x, (u64)(ts->x))
# define P_ns(x) \
SEQ_printf(m, " .%-15s: %Ld nsecs\n", #x, \
(u64)(ktime_to_ns(ts->x)))
{
struct tick_sched *ts = tick_get_tick_sched(cpu);
P(nohz_mode);
P_ns(idle_tick);
P(tick_stopped);
P(idle_jiffies);
P(idle_calls);
P(idle_sleeps);
P_ns(idle_entrytime);
P_ns(idle_sleeptime);
P(last_jiffies);
P(next_jiffies);
P_ns(idle_expires);
SEQ_printf(m, "jiffies: %Ld\n", (u64)jiffies);
}
#endif
#undef P
#undef P_ns
}
#ifdef CONFIG_GENERIC_CLOCKEVENTS
static void
print_tickdevice(struct seq_file *m, struct tick_device *td)
{
struct clock_event_device *dev = td->evtdev;
SEQ_printf(m, "\nTick Device: mode: %d\n", td->mode);
SEQ_printf(m, "Clock Event Device: ");
if (!dev) {
SEQ_printf(m, "<NULL>\n");
return;
}
SEQ_printf(m, "%s\n", dev->name);
SEQ_printf(m, " max_delta_ns: %ld\n", dev->max_delta_ns);
SEQ_printf(m, " min_delta_ns: %ld\n", dev->min_delta_ns);
SEQ_printf(m, " mult: %ld\n", dev->mult);
SEQ_printf(m, " shift: %d\n", dev->shift);
SEQ_printf(m, " mode: %d\n", dev->mode);
SEQ_printf(m, " next_event: %Ld nsecs\n",
(unsigned long long) ktime_to_ns(dev->next_event));
SEQ_printf(m, " set_next_event: ");
print_name_offset(m, dev->set_next_event);
SEQ_printf(m, "\n");
SEQ_printf(m, " set_mode: ");
print_name_offset(m, dev->set_mode);
SEQ_printf(m, "\n");
SEQ_printf(m, " event_handler: ");
print_name_offset(m, dev->event_handler);
SEQ_printf(m, "\n");
}
static void timer_list_show_tickdevices(struct seq_file *m)
{
int cpu;
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
print_tickdevice(m, tick_get_broadcast_device());
SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
tick_get_broadcast_mask()->bits[0]);
#ifdef CONFIG_TICK_ONESHOT
SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
tick_get_broadcast_oneshot_mask()->bits[0]);
#endif
SEQ_printf(m, "\n");
#endif
for_each_online_cpu(cpu)
print_tickdevice(m, tick_get_device(cpu));
SEQ_printf(m, "\n");
}
#else
static void timer_list_show_tickdevices(struct seq_file *m) { }
#endif
static int timer_list_show(struct seq_file *m, void *v)
{
u64 now = ktime_to_ns(ktime_get());
int cpu;
SEQ_printf(m, "Timer List Version: v0.3\n");
SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
for_each_online_cpu(cpu)
print_cpu(m, cpu, now);
SEQ_printf(m, "\n");
timer_list_show_tickdevices(m);
return 0;
}
void sysrq_timer_list_show(void)
{
timer_list_show(NULL, NULL);
}
static int timer_list_open(struct inode *inode, struct file *filp)
{
return single_open(filp, timer_list_show, NULL);
}
static struct file_operations timer_list_fops = {
.open = timer_list_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init init_timer_list_procfs(void)
{
struct proc_dir_entry *pe;
pe = create_proc_entry("timer_list", 0644, NULL);
if (!pe)
return -ENOMEM;
pe->proc_fops = &timer_list_fops;
return 0;
}
__initcall(init_timer_list_procfs);
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