linux/kernel/time
Baolin Wang 4a057549d6 alarmtimer: Add tracepoints for alarm timers
Alarm timers are one of the mechanisms to wake up a system from suspend,
but there exist no tracepoints to analyse which process/thread armed an
alarmtimer.

Add tracepoints for start/cancel/expire of individual alarm timers and one
for tracing the suspend time decision when to resume the system.

The following trace excerpt illustrates the new mechanism:

Binder:3292_2-3304  [000] d..2   149.981123: alarmtimer_cancel:
alarmtimer:ffffffc1319a7800 type:REALTIME
expires:1325463120000000000 now:1325376810370370245

Binder:3292_2-3304  [000] d..2   149.981136: alarmtimer_start:
alarmtimer:ffffffc1319a7800 type:REALTIME
expires:1325376840000000000 now:1325376810370384591

Binder:3292_9-3953  [000] d..2   150.212991: alarmtimer_cancel:
alarmtimer:ffffffc1319a5a00 type:BOOTTIME
expires:179552000000 now:150154008122

Binder:3292_9-3953  [000] d..2   150.213006: alarmtimer_start:
alarmtimer:ffffffc1319a5a00 type:BOOTTIME
expires:179551000000 now:150154025622

system_server-3000  [002] ...1  162.701940: alarmtimer_suspend:
alarmtimer type:REALTIME expires:1325376840000000000

The wakeup time which is selected at suspend time allows to map it back to
the task arming the timer: Binder:3292_2.

[ tglx: Store alarm timer expiry time instead of some useless RTC relative
  	information, add proper type information for wakeups which are
  	handled via the clock_nanosleep/freezer and massage the changelog. ]

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1480372524-15181-5-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-01 14:45:08 +01:00
..
alarmtimer.c alarmtimer: Add tracepoints for alarm timers 2016-12-01 14:45:08 +01:00
clockevents.c clockevents: Make clockevents_subsys static 2016-07-19 10:48:06 +02:00
clocksource.c clocksource: Defer override invalidation unless clock is unstable 2016-08-31 14:43:33 -07:00
hrtimer.c timers: Fix documentation for schedule_timeout() and similar 2016-10-26 13:14:47 +02:00
itimer.c timer: Move sys_alarm from timer.c to itimer.c 2016-11-16 09:26:34 +01:00
jiffies.c jiffies: Use CLOCKSOURCE_MASK instead of constant 2016-02-27 08:55:31 +01:00
Kconfig rcu: Drop RCU_USER_QS in favor of NO_HZ_FULL 2015-07-06 13:52:18 -07:00
Makefile posix-timers: Make them configurable 2016-11-16 09:26:35 +01:00
ntp_internal.h ntp: Fix second_overflow's input parameter type to be 64bits 2015-12-16 16:50:56 -08:00
ntp.c ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO 2016-01-22 12:01:42 +01:00
posix-clock.c posix-clock: Fix return code on the poll method's error path 2015-12-29 11:33:06 +01:00
posix-cpu-timers.c posix_cpu_timers: Move the add_device_randomness() call to a proper place 2016-11-16 09:26:34 +01:00
posix-stubs.c posix-timers: Make them configurable 2016-11-16 09:26:35 +01:00
posix-timers.c posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper 2016-01-17 11:13:55 +01:00
sched_clock.c timers, sched/clock: Clean up the code a bit 2015-03-27 08:34:01 +01:00
test_udelay.c time: Avoid timespec in udelay_test 2016-06-20 12:47:26 -07:00
tick-broadcast-hrtimer.c tick/broadcast-hrtimer: Set name of the ce_broadcast_hrtimer 2016-07-05 17:02:19 +02:00
tick-broadcast.c tick: Move the export of tick_broadcast_oneshot_control to the proper place 2015-07-14 12:01:04 +02:00
tick-common.c clockevents: Remove unused set_mode() callback 2015-09-14 11:00:55 +02:00
tick-internal.h timers: Forward the wheel clock whenever possible 2016-07-07 10:35:11 +02:00
tick-oneshot.c clockevents: Provide functions to set and get the state 2015-06-02 14:40:47 +02:00
tick-sched.c tick/nohz: Prevent stopping the tick on an offline CPU 2016-09-13 17:53:52 +02:00
tick-sched.h timers/nohz: Convert tick dependency mask to atomic_t 2016-03-29 11:52:11 +02:00
time.c time: Avoid undefined behaviour in timespec64_add_safe() 2016-08-31 14:43:35 -07:00
timeconst.bc timeconst: Update path in comment 2015-10-26 10:06:06 +09:00
timeconv.c time: Add time64_to_tm() 2016-06-20 12:47:15 -07:00
timecounter.c timecounter: keep track of accumulated fractional nanoseconds 2014-12-30 18:29:27 -05:00
timekeeping_debug.c timekeeping: Prints the amounts of time spent during suspend 2016-08-31 14:43:34 -07:00
timekeeping_internal.h clocksource: Make clocksource validation work for all clocksources 2015-12-19 15:59:57 +01:00
timekeeping.c timekeeping: Add a fast and NMI safe boot clock 2016-11-29 18:02:59 +01:00
timekeeping.h hrtimer: Make offset update smarter 2015-04-22 17:06:49 +02:00
timer_list.c hrtimer: Handle remaining time proper for TIME_LOW_RES 2016-01-17 11:13:55 +01:00
timer_stats.c timer: Avoid using timespec 2016-06-20 12:47:33 -07:00
timer.c posix-timers: Make them configurable 2016-11-16 09:26:35 +01:00