+/* Copyright (C) 1991-2017, the Linux Kernel authors */
+
#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.
+ * A simple "approximate counter".
*/
-#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
+#include <atomic.h>
+#include <list.h>
struct percpu_counter {
- raw_spinlock_t lock;
- s64 count;
+ spinlock_t lock;
+ int64_t count;
#ifdef CONFIG_HOTPLUG_CPU
struct list_head list; /* All percpu_counters are on a list */
#endif
- s32 __percpu *counters;
+ int32_t *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); \
- })
-
+int percpu_counter_init(struct percpu_counter *fbc, int64_t amount, int gfp);
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);
+void percpu_counter_set(struct percpu_counter *fbc, int64_t amount);
+void percpu_counter_add_batch(struct percpu_counter *fbc, int64_t amount,
+ int32_t batch);
+int64_t __percpu_counter_sum(struct percpu_counter *fbc);
+int __percpu_counter_compare(struct percpu_counter *fbc, int64_t rhs,
+ int32_t batch);
-static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
+static inline int percpu_counter_compare(struct percpu_counter *fbc,
+ int64_t rhs)
{
return __percpu_counter_compare(fbc, rhs, percpu_counter_batch);
}
-static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount)
+static inline void percpu_counter_add(struct percpu_counter *fbc,
+ int64_t amount)
{
percpu_counter_add_batch(fbc, amount, percpu_counter_batch);
}
-static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
+static inline int64_t percpu_counter_sum_positive(struct percpu_counter *fbc)
{
- s64 ret = __percpu_counter_sum(fbc);
+ int64_t ret = __percpu_counter_sum(fbc);
return ret < 0 ? 0 : ret;
}
-static inline s64 percpu_counter_sum(struct percpu_counter *fbc)
+static inline int64_t percpu_counter_sum(struct percpu_counter *fbc)
{
return __percpu_counter_sum(fbc);
}
-static inline s64 percpu_counter_read(struct percpu_counter *fbc)
+static inline int64_t percpu_counter_read(struct percpu_counter *fbc)
{
return fbc->count;
}
* number for some counter which should never be negative.
*
*/
-static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc)
+static inline int64_t percpu_counter_read_positive(struct percpu_counter *fbc)
{
- s64 ret = fbc->count;
+ int64_t ret = fbc->count;
- barrier(); /* Prevent reloads of fbc->count */
+ cmb(); /* Prevent reloads of fbc->count */
if (ret >= 0)
return ret;
return 0;
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 int percpu_counter_initialized(struct percpu_counter *fbc)
-{
- return 1;
-}
-
-#endif /* CONFIG_SMP */
-
static inline void percpu_counter_inc(struct percpu_counter *fbc)
{
percpu_counter_add(fbc, 1);
percpu_counter_add(fbc, -1);
}
-static inline void percpu_counter_sub(struct percpu_counter *fbc, s64 amount)
+static inline void percpu_counter_sub(struct percpu_counter *fbc,
+ int64_t amount)
{
percpu_counter_add(fbc, -amount);
}
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