Commit 8102c4da authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Thomas Gleixner
Browse files

timekeeping: Add the boot clock to system time snapshot 



For tracing purpose, the boot clock is interesting as it doesn't stop on
suspend. Export it as part of the time snapshot. This will later allow
the hypervisor to add boot clock timestamps to its events.

Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarJohn Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20240911093029.3279154-5-vdonnefort@google.com
parent 9852d85e

include/linux/timekeeping.h

+2 −0
Original line number Diff line number Diff line
@@ -275,6 +275,7 @@ struct ktime_timestamps { 
 *				 counter value

 * @cycles:	Clocksource counter value to produce the system times

 * @real:	Realtime system time

 * @boot:	Boot time

 * @raw:	Monotonic raw system time

 * @cs_id:	Clocksource ID

 * @clock_was_set_seq:	The sequence number of clock-was-set events
@@ -283,6 +284,7 @@ struct ktime_timestamps { 
struct system_time_snapshot {

	u64			cycles;

	ktime_t			real;

	ktime_t			boot;

	ktime_t			raw;

	enum clocksource_ids	cs_id;

	unsigned int		clock_was_set_seq;

kernel/time/timekeeping.c

+4 −0
Original line number Diff line number Diff line
@@ -1060,6 +1060,7 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) 
	unsigned int seq;

	ktime_t base_raw;

	ktime_t base_real;

	ktime_t base_boot;

	u64 nsec_raw;

	u64 nsec_real;

	u64 now;
@@ -1074,6 +1075,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) 
		systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq;

		base_real = ktime_add(tk->tkr_mono.base,

				      tk_core.timekeeper.offs_real);

		base_boot = ktime_add(tk->tkr_mono.base,

				      tk_core.timekeeper.offs_boot);

		base_raw = tk->tkr_raw.base;

		nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now);

		nsec_raw  = timekeeping_cycles_to_ns(&tk->tkr_raw, now);
@@ -1081,6 +1084,7 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) 


	systime_snapshot->cycles = now;

	systime_snapshot->real = ktime_add_ns(base_real, nsec_real);

	systime_snapshot->boot = ktime_add_ns(base_boot, nsec_real);

	systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw);

}

EXPORT_SYMBOL_GPL(ktime_get_snapshot);