kernel/time/timekeeping_internal.h

Source file repositories/reference/linux-study-clean/kernel/time/timekeeping_internal.h

File Facts

System
Linux kernel
Corpus path
kernel/time/timekeeping_internal.h
Extension
.h
Size
1183 bytes
Lines
52
Domain
Core OS
Bucket
Scheduler, Processes, Timers, Sync, And Syscalls
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _TIMEKEEPING_INTERNAL_H
#define _TIMEKEEPING_INTERNAL_H

#include <linux/clocksource.h>
#include <linux/spinlock.h>
#include <linux/time.h>

/*
 * timekeeping debug functions
 */
#ifdef CONFIG_DEBUG_FS

DECLARE_PER_CPU(unsigned long, timekeeping_mg_floor_swaps);

static inline void timekeeping_inc_mg_floor_swaps(void)
{
	this_cpu_inc(timekeeping_mg_floor_swaps);
}

extern void tk_debug_account_sleep_time(const struct timespec64 *t);

#else

#define tk_debug_account_sleep_time(x)

static inline void timekeeping_inc_mg_floor_swaps(void)
{
}

#endif

static inline u64 clocksource_delta(u64 now, u64 last, u64 mask, u64 max_delta)
{
	u64 ret = (now - last) & mask;

	/*
	 * Prevent time going backwards by checking the result against
	 * @max_delta. If greater, return 0.
	 */
	return ret > max_delta ? 0 : ret;
}

/* Semi public for serialization of non timekeeper VDSO updates. */
unsigned long timekeeper_lock_irqsave(void);
void timekeeper_unlock_irqrestore(unsigned long flags);

/* NTP specific interface to access the current seconds value */
long ktime_get_ntp_seconds(unsigned int id);

#endif /* _TIMEKEEPING_INTERNAL_H */

Annotation

Implementation Notes