#ifndef _LINUX_KERNEL_STAT_H
  #define _LINUX_KERNEL_STAT_H

  #include <linux/smp.h>
  #include <linux/threads.h>
  #include <linux/percpu.h>

  #include <linux/cpumask.h>

  #include <linux/interrupt.h>

  #include <linux/sched.h>

  #include <asm/irq.h>

  #include <asm/cputime.h>
  
  /*
   * 'kernel_stat.h' contains the definitions needed for doing
   * some kernel statistics (CPU usage, context switches ...),
   * used by rstatd/perfmeter
   */

  enum cpu_usage_stat {
  	CPUTIME_USER,
  	CPUTIME_NICE,
  	CPUTIME_SYSTEM,
  	CPUTIME_SOFTIRQ,
  	CPUTIME_IRQ,
  	CPUTIME_IDLE,
  	CPUTIME_IOWAIT,
  	CPUTIME_STEAL,
  	CPUTIME_GUEST,
  	CPUTIME_GUEST_NICE,
  	NR_STATS,
  };
  
  struct kernel_cpustat {
  	u64 cpustat[NR_STATS];

  };
  
  struct kernel_stat {

  #ifndef CONFIG_GENERIC_HARDIRQS

         unsigned int irqs[NR_IRQS];
  #endif

  	unsigned long irqs_sum;

  	unsigned int softirqs[NR_SOFTIRQS];

  };
  
  DECLARE_PER_CPU(struct kernel_stat, kstat);

  DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat);

  /* Must have preemption disabled for this to be meaningful. */

  #define kstat_this_cpu (&__get_cpu_var(kstat))
  #define kcpustat_this_cpu (&__get_cpu_var(kernel_cpustat))
  #define kstat_cpu(cpu) per_cpu(kstat, cpu)
  #define kcpustat_cpu(cpu) per_cpu(kernel_cpustat, cpu)

  
  extern unsigned long long nr_context_switches(void);

  #ifndef CONFIG_GENERIC_HARDIRQS

  struct irq_desc;

  static inline void kstat_incr_irqs_this_cpu(unsigned int irq,
  					    struct irq_desc *desc)
  {

  	__this_cpu_inc(kstat.irqs[irq]);
  	__this_cpu_inc(kstat.irqs_sum);

  }

  static inline unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
  {
         return kstat_cpu(cpu).irqs[irq];
  }

  #else

  #include <linux/irq.h>

  extern unsigned int kstat_irqs_cpu(unsigned int irq, int cpu);

  
  #define kstat_incr_irqs_this_cpu(irqno, DESC)		\
  do {							\
  	__this_cpu_inc(*(DESC)->kstat_irqs);		\
  	__this_cpu_inc(kstat.irqs_sum);			\
  } while (0)

  #endif

  static inline void kstat_incr_softirqs_this_cpu(unsigned int irq)
  {

  	__this_cpu_inc(kstat.softirqs[irq]);

  }
  
  static inline unsigned int kstat_softirqs_cpu(unsigned int irq, int cpu)
  {
         return kstat_cpu(cpu).softirqs[irq];
  }

  /*
   * Number of interrupts per specific IRQ source, since bootup
   */

  #ifndef CONFIG_GENERIC_HARDIRQS

  static inline unsigned int kstat_irqs(unsigned int irq)

  {

  	unsigned int sum = 0;
  	int cpu;

  	for_each_possible_cpu(cpu)

  		sum += kstat_irqs_cpu(irq, cpu);

  
  	return sum;
  }

  #else
  extern unsigned int kstat_irqs(unsigned int irq);
  #endif

  /*
   * Number of interrupts per cpu, since bootup
   */
  static inline unsigned int kstat_cpu_irqs_sum(unsigned int cpu)
  {
  	return kstat_cpu(cpu).irqs_sum;
  }

  
  /*
   * Lock/unlock the current runqueue - to extract task statistics:
   */

  extern unsigned long long task_delta_exec(struct task_struct *);

  extern void account_user_time(struct task_struct *, cputime_t, cputime_t);
  extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t);

  extern void account_steal_time(cputime_t);
  extern void account_idle_time(cputime_t);
  
  extern void account_process_tick(struct task_struct *, int user);
  extern void account_steal_ticks(unsigned long ticks);
  extern void account_idle_ticks(unsigned long ticks);

  
  #endif /* _LINUX_KERNEL_STAT_H */