Commit 289f480a authored Feb 16, 2007 by Ingo Molnar Committed by Linus Torvalds Feb 16, 2007

[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: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 82f67cd9

include/linux/tick.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -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);

kernel/time/Makefile

+1 −1

Original line number	Diff line number	Diff line
		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

kernel/time/tick-broadcast.c

+21 −0

Original line number	Diff line number	Diff line
		@@ -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;

kernel/time/tick-common.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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
		*/

kernel/time/tick-sched.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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 !
		*/