Contributors: 16
	  
        
          | Author | 
          Tokens | 
          Token Proportion | 
          Commits | 
          Commit Proportion | 
        
	  
	  
        
        
          | Andrew Morton | 
          270 | 
          40.36% | 
          5 | 
          16.67% | 
        
        
          | Peter Zijlstra | 
          173 | 
          25.86% | 
          10 | 
          33.33% | 
        
        
          | David Chinner | 
          55 | 
          8.22% | 
          1 | 
          3.33% | 
        
        
          | Tim Chen | 
          54 | 
          8.07% | 
          1 | 
          3.33% | 
        
        
          | Theodore Y. Ts'o | 
          33 | 
          4.93% | 
          1 | 
          3.33% | 
        
        
          | Anton Blanchard | 
          24 | 
          3.59% | 
          1 | 
          3.33% | 
        
        
          | Mingming Cao | 
          22 | 
          3.29% | 
          1 | 
          3.33% | 
        
        
          | Tejun Heo | 
          13 | 
          1.94% | 
          2 | 
          6.67% | 
        
        
          | Adrian Bunk | 
          9 | 
          1.35% | 
          1 | 
          3.33% | 
        
        
          | Eric Dumazet | 
          5 | 
          0.75% | 
          1 | 
          3.33% | 
        
        
          | guoyayun | 
          3 | 
          0.45% | 
          1 | 
          3.33% | 
        
        
          | Nikolay Borisov | 
          3 | 
          0.45% | 
          1 | 
          3.33% | 
        
        
          | Shaohua Li | 
          2 | 
          0.30% | 
          1 | 
          3.33% | 
        
        
          | Jesper Dangaard Brouer | 
          1 | 
          0.15% | 
          1 | 
          3.33% | 
        
        
          | Greg Kroah-Hartman | 
          1 | 
          0.15% | 
          1 | 
          3.33% | 
        
        
          | Thomas Gleixner | 
          1 | 
          0.15% | 
          1 | 
          3.33% | 
        
	  
	  
        
          | Total | 
          669 | 
           | 
          30 | 
           | 
	    
	  
    
 
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PERCPU_COUNTER_H
#define _LINUX_PERCPU_COUNTER_H
/*
 * A simple "approximate counter" for use in ext2 and ext3 superblocks.
 *
 * WARNING: these things are HUGE.  4 kbytes per counter on 32-way P4.
 */
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/list.h>
#include <linux/threads.h>
#include <linux/percpu.h>
#include <linux/types.h>
#include <linux/gfp.h>
#ifdef CONFIG_SMP
struct percpu_counter {
	raw_spinlock_t lock;
	s64 count;
#ifdef CONFIG_HOTPLUG_CPU
	struct list_head list;	/* All percpu_counters are on a list */
#endif
	s32 __percpu *counters;
};
extern int percpu_counter_batch;
int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, gfp_t gfp,
			  struct lock_class_key *key);
#define percpu_counter_init(fbc, value, gfp)				\
	({								\
		static struct lock_class_key __key;			\
									\
		__percpu_counter_init(fbc, value, gfp, &__key);		\
	})
void percpu_counter_destroy(struct percpu_counter *fbc);
void percpu_counter_set(struct percpu_counter *fbc, s64 amount);
void percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount,
			      s32 batch);
s64 __percpu_counter_sum(struct percpu_counter *fbc);
int __percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch);
static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
{
	return __percpu_counter_compare(fbc, rhs, percpu_counter_batch);
}
static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount)
{
	percpu_counter_add_batch(fbc, amount, percpu_counter_batch);
}
static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
{
	s64 ret = __percpu_counter_sum(fbc);
	return ret < 0 ? 0 : ret;
}
static inline s64 percpu_counter_sum(struct percpu_counter *fbc)
{
	return __percpu_counter_sum(fbc);
}
static inline s64 percpu_counter_read(struct percpu_counter *fbc)
{
	return fbc->count;
}
/*
 * It is possible for the percpu_counter_read() to return a small negative
 * number for some counter which should never be negative.
 *
 */
static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc)
{
	s64 ret = fbc->count;
	barrier();		/* Prevent reloads of fbc->count */
	if (ret >= 0)
		return ret;
	return 0;
}
static inline bool percpu_counter_initialized(struct percpu_counter *fbc)
{
	return (fbc->counters != NULL);
}
#else /* !CONFIG_SMP */
struct percpu_counter {
	s64 count;
};
static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount,
				      gfp_t gfp)
{
	fbc->count = amount;
	return 0;
}
static inline void percpu_counter_destroy(struct percpu_counter *fbc)
{
}
static inline void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
{
	fbc->count = amount;
}
static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
{
	if (fbc->count > rhs)
		return 1;
	else if (fbc->count < rhs)
		return -1;
	else
		return 0;
}
static inline int
__percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch)
{
	return percpu_counter_compare(fbc, rhs);
}
static inline void
percpu_counter_add(struct percpu_counter *fbc, s64 amount)
{
	preempt_disable();
	fbc->count += amount;
	preempt_enable();
}
static inline void
percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, s32 batch)
{
	percpu_counter_add(fbc, amount);
}
static inline s64 percpu_counter_read(struct percpu_counter *fbc)
{
	return fbc->count;
}
/*
 * percpu_counter is intended to track positive numbers. In the UP case the
 * number should never be negative.
 */
static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc)
{
	return fbc->count;
}
static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
{
	return percpu_counter_read_positive(fbc);
}
static inline s64 percpu_counter_sum(struct percpu_counter *fbc)
{
	return percpu_counter_read(fbc);
}
static inline bool percpu_counter_initialized(struct percpu_counter *fbc)
{
	return true;
}
#endif	/* CONFIG_SMP */
static inline void percpu_counter_inc(struct percpu_counter *fbc)
{
	percpu_counter_add(fbc, 1);
}
static inline void percpu_counter_dec(struct percpu_counter *fbc)
{
	percpu_counter_add(fbc, -1);
}
static inline void percpu_counter_sub(struct percpu_counter *fbc, s64 amount)
{
	percpu_counter_add(fbc, -amount);
}
#endif /* _LINUX_PERCPU_COUNTER_H */