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timekeeping: Provide update for auxiliary timekeepers

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Update the auxiliary timekeepers periodically. For now this is tied to the system
timekeeper update from the tick. This might be revisited and moved out of the tick.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250625183758.382451331@linutronix.de
This commit is contained in:
Thomas Gleixner 2025-06-25 20:38:47 +02:00
parent ecf3e70304
commit e6d4c00719
1 changed files with 19 additions and 0 deletions
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19
kernel/time/timekeeping.c
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@ -131,9 +131,11 @@ static struct tk_fast tk_fast_raw ____cacheline_aligned = {
#ifdef CONFIG_POSIX_AUX_CLOCKS
static __init void tk_aux_setup(void);
static void tk_aux_update_clocksource(void);
static void tk_aux_advance(void);
#else
static inline void tk_aux_setup(void) { }
static inline void tk_aux_update_clocksource(void) { }
static inline void tk_aux_advance(void) { }
#endif
unsigned long timekeeper_lock_irqsave(void)
@ -2317,11 +2319,13 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode)
/**
* update_wall_time - Uses the current clocksource to increment the wall time
*
* It also updates the enabled auxiliary clock timekeepers
*/
void update_wall_time(void)
{
if (timekeeping_advance(TK_ADV_TICK))
clock_was_set_delayed();
tk_aux_advance();
}
/**
@ -2764,6 +2768,21 @@ static void tk_aux_update_clocksource(void)
}
}
static void tk_aux_advance(void)
{
unsigned long active = READ_ONCE(aux_timekeepers);
unsigned int id;
/* Lockless quick check to avoid extra cache lines */
for_each_set_bit(id, &active, BITS_PER_LONG) {
struct tk_data *aux_tkd = &timekeeper_data[id + TIMEKEEPER_AUX_FIRST];
guard(raw_spinlock)(&aux_tkd->lock);
if (aux_tkd->shadow_timekeeper.clock_valid)
__timekeeping_advance(aux_tkd, TK_ADV_TICK);
}
}
/**
* ktime_get_aux - Get time for a AUX clock
* @id: ID of the clock to read (CLOCK_AUX...)