Commit c1955a3d authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched_clock: delay using sched_clock() 



Some arch's can't handle sched_clock() being called too early - delay
this until sched_clock_init() has been called.

Reported-by: default avatarBill Gatliff <bgat@billgatliff.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: default avatarNishanth Aravamudan <nacc@us.ibm.com>
CC: Russell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 4a273f20

include/linux/sched.h

+3 −11
Original line number Diff line number Diff line
@@ -1551,16 +1551,10 @@ static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask) 


extern unsigned long long sched_clock(void);



#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK

static inline void sched_clock_init(void)

{

}



static inline u64 sched_clock_cpu(int cpu)

{

	return sched_clock();

}

extern void sched_clock_init(void);

extern u64 sched_clock_cpu(int cpu);



#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK

static inline void sched_clock_tick(void)

{

}
@@ -1573,8 +1567,6 @@ static inline void sched_clock_idle_wakeup_event(u64 delta_ns) 
{

}

#else

extern void sched_clock_init(void);

extern u64 sched_clock_cpu(int cpu);

extern void sched_clock_tick(void);

extern void sched_clock_idle_sleep_event(void);

extern void sched_clock_idle_wakeup_event(u64 delta_ns);

kernel/sched_clock.c

+17 −2
Original line number Diff line number Diff line
@@ -42,6 +42,8 @@ unsigned long long __attribute__((weak)) sched_clock(void) 
	return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);

}



static __read_mostly int sched_clock_running;



#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK



struct sched_clock_data {
@@ -70,8 +72,6 @@ static inline struct sched_clock_data *cpu_sdc(int cpu) 
	return &per_cpu(sched_clock_data, cpu);

}



static __read_mostly int sched_clock_running;



void sched_clock_init(void)

{

	u64 ktime_now = ktime_to_ns(ktime_get());
@@ -248,6 +248,21 @@ void sched_clock_idle_wakeup_event(u64 delta_ns) 
}

EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);



#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */



void sched_clock_init(void)

{

	sched_clock_running = 1;

}



u64 sched_clock_cpu(int cpu)

{

	if (unlikely(!sched_clock_running))

		return 0;



	return sched_clock();

}



#endif



unsigned long long cpu_clock(int cpu)

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