1 #ifndef _LINUX_SCHED_CLOCK_H
2 #define _LINUX_SCHED_CLOCK_H
7 * Do not use outside of architecture code which knows its limitations.
9 * sched_clock() has no promise of monotonicity or bounded drift between
10 * CPUs, use (which you should not) requires disabling IRQs.
12 * Please use one of the three interfaces below.
14 extern unsigned long long notrace sched_clock(void);
17 * See the comment in kernel/sched/clock.c
19 extern u64 running_clock(void);
20 extern u64 sched_clock_cpu(int cpu);
23 extern void sched_clock_init(void);
25 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
26 static inline void sched_clock_tick(void)
30 static inline void clear_sched_clock_stable(void)
34 static inline void sched_clock_idle_sleep_event(void)
38 static inline void sched_clock_idle_wakeup_event(void)
42 static inline u64 cpu_clock(int cpu)
47 static inline u64 local_clock(void)
52 extern int sched_clock_stable(void);
53 extern void clear_sched_clock_stable(void);
56 * When sched_clock_stable(), __sched_clock_offset provides the offset
57 * between local_clock() and sched_clock().
59 extern u64 __sched_clock_offset;
61 extern void sched_clock_tick(void);
62 extern void sched_clock_tick_stable(void);
63 extern void sched_clock_idle_sleep_event(void);
64 extern void sched_clock_idle_wakeup_event(void);
67 * As outlined in clock.c, provides a fast, high resolution, nanosecond
68 * time source that is monotonic per cpu argument and has bounded drift
71 * ######################### BIG FAT WARNING ##########################
72 * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
74 * ####################################################################
76 static inline u64 cpu_clock(int cpu)
78 return sched_clock_cpu(cpu);
81 static inline u64 local_clock(void)
83 return sched_clock_cpu(raw_smp_processor_id());
87 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
89 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
90 * The reason for this explicit opt-in is not to have perf penalty with
93 extern void enable_sched_clock_irqtime(void);
94 extern void disable_sched_clock_irqtime(void);
96 static inline void enable_sched_clock_irqtime(void) {}
97 static inline void disable_sched_clock_irqtime(void) {}
100 #endif /* _LINUX_SCHED_CLOCK_H */