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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SCHED_CLOCK_H
#define _LINUX_SCHED_CLOCK_H
#include <linux/smp.h>
/*
* Do not use outside of architecture code which knows its limitations.
*
* sched_clock() has no promise of monotonicity or bounded drift between
* CPUs, use (which you should not) requires disabling IRQs.
*
* Please use one of the three interfaces below.
*/
extern unsigned long long notrace sched_clock(void);
/*
* See the comment in kernel/sched/clock.c
*/
extern u64 running_clock(void);
extern u64 sched_clock_cpu(int cpu);
extern void sched_clock_init(void);
#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
static inline void sched_clock_tick(void)
{
}
static inline void clear_sched_clock_stable(void)
{
}
static inline void sched_clock_idle_sleep_event(void)
{
}
static inline void sched_clock_idle_wakeup_event(void)
{
}
static inline u64 cpu_clock(int cpu)
{
return sched_clock();
}
static inline u64 local_clock(void)
{
return sched_clock();
}
#else
extern int sched_clock_stable(void);
extern void clear_sched_clock_stable(void);
/*
* When sched_clock_stable(), __sched_clock_offset provides the offset
* between local_clock() and sched_clock().
*/
extern u64 __sched_clock_offset;
extern void sched_clock_tick(void);
extern void sched_clock_tick_stable(void);
extern void sched_clock_idle_sleep_event(void);
extern void sched_clock_idle_wakeup_event(void);
/*
* As outlined in clock.c, provides a fast, high resolution, nanosecond
* time source that is monotonic per cpu argument and has bounded drift
* between cpus.
*
* ######################### BIG FAT WARNING ##########################
* # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
* # go backwards !! #
* ####################################################################
*/
static inline u64 cpu_clock(int cpu)
{
return sched_clock_cpu(cpu);
}
static inline u64 local_clock(void)
{
return sched_clock_cpu(raw_smp_processor_id());
}
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
/*
* An i/f to runtime opt-in for irq time accounting based off of sched_clock.
* The reason for this explicit opt-in is not to have perf penalty with
* slow sched_clocks.
*/
extern void enable_sched_clock_irqtime(void);
extern void disable_sched_clock_irqtime(void);
#else
static inline void enable_sched_clock_irqtime(void) {}
static inline void disable_sched_clock_irqtime(void) {}
#endif
#endif /* _LINUX_SCHED_CLOCK_H */
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