linux_dsm_epyc7002/include/linux/alarmtimer.h
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

65 lines
1.8 KiB
C

#ifndef _LINUX_ALARMTIMER_H
#define _LINUX_ALARMTIMER_H
#include <linux/time.h>
#include <linux/hrtimer.h>
#include <linux/timerqueue.h>
#include <linux/rtc.h>
enum alarmtimer_type {
ALARM_REALTIME,
ALARM_BOOTTIME,
/* Supported types end here */
ALARM_NUMTYPE,
/* Used for tracing information. No usable types. */
ALARM_REALTIME_FREEZER,
ALARM_BOOTTIME_FREEZER,
};
enum alarmtimer_restart {
ALARMTIMER_NORESTART,
ALARMTIMER_RESTART,
};
#define ALARMTIMER_STATE_INACTIVE 0x00
#define ALARMTIMER_STATE_ENQUEUED 0x01
/**
* struct alarm - Alarm timer structure
* @node: timerqueue node for adding to the event list this value
* also includes the expiration time.
* @timer: hrtimer used to schedule events while running
* @function: Function pointer to be executed when the timer fires.
* @type: Alarm type (BOOTTIME/REALTIME).
* @state: Flag that represents if the alarm is set to fire or not.
* @data: Internal data value.
*/
struct alarm {
struct timerqueue_node node;
struct hrtimer timer;
enum alarmtimer_restart (*function)(struct alarm *, ktime_t now);
enum alarmtimer_type type;
int state;
void *data;
};
void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
enum alarmtimer_restart (*function)(struct alarm *, ktime_t));
void alarm_start(struct alarm *alarm, ktime_t start);
void alarm_start_relative(struct alarm *alarm, ktime_t start);
void alarm_restart(struct alarm *alarm);
int alarm_try_to_cancel(struct alarm *alarm);
int alarm_cancel(struct alarm *alarm);
u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval);
u64 alarm_forward_now(struct alarm *alarm, ktime_t interval);
ktime_t alarm_expires_remaining(const struct alarm *alarm);
/* Provide way to access the rtc device being used by alarmtimers */
struct rtc_device *alarmtimer_get_rtcdev(void);
#endif