* WARNING: these things are HUGE. 4 kbytes per counter on 32-way P4.
*/
-#include <linux/config.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
+#include <linux/list.h>
#include <linux/threads.h>
#include <linux/percpu.h>
+#include <linux/types.h>
#ifdef CONFIG_SMP
struct percpu_counter {
spinlock_t lock;
- long count;
- long *counters;
+ s64 count;
+#ifdef CONFIG_HOTPLUG_CPU
+ struct list_head list; /* All percpu_counters are on a list */
+#endif
+ s32 *counters;
};
#if NR_CPUS >= 16
#define FBC_BATCH (NR_CPUS*4)
#endif
-static inline void percpu_counter_init(struct percpu_counter *fbc)
+int percpu_counter_init(struct percpu_counter *fbc, s64 amount);
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount);
+void percpu_counter_destroy(struct percpu_counter *fbc);
+void percpu_counter_set(struct percpu_counter *fbc, s64 amount);
+void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch);
+s64 __percpu_counter_sum(struct percpu_counter *fbc);
+
+static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount)
{
- spin_lock_init(&fbc->lock);
- fbc->count = 0;
- fbc->counters = alloc_percpu(long);
+ __percpu_counter_add(fbc, amount, FBC_BATCH);
}
-static inline void percpu_counter_destroy(struct percpu_counter *fbc)
+static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc)
{
- free_percpu(fbc->counters);
+ s64 ret = __percpu_counter_sum(fbc);
+ return ret < 0 ? 0 : ret;
}
-void percpu_counter_mod(struct percpu_counter *fbc, long amount);
-long percpu_counter_sum(struct percpu_counter *fbc);
+static inline s64 percpu_counter_sum(struct percpu_counter *fbc)
+{
+ return __percpu_counter_sum(fbc);
+}
-static inline long percpu_counter_read(struct percpu_counter *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 long percpu_counter_read_positive(struct percpu_counter *fbc)
+static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc)
{
- long ret = fbc->count;
+ s64 ret = fbc->count;
barrier(); /* Prevent reloads of fbc->count */
- if (ret > 0)
+ if (ret >= 0)
return ret;
return 1;
}
#else
struct percpu_counter {
- long count;
+ s64 count;
};
-static inline void percpu_counter_init(struct percpu_counter *fbc)
+static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
{
- fbc->count = 0;
+ fbc->count = amount;
+ return 0;
}
+#define percpu_counter_init_irq percpu_counter_init
+
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;
+}
+
+#define __percpu_counter_add(fbc, amount, batch) \
+ percpu_counter_add(fbc, amount)
+
static inline void
-percpu_counter_mod(struct percpu_counter *fbc, long amount)
+percpu_counter_add(struct percpu_counter *fbc, s64 amount)
{
preempt_disable();
fbc->count += amount;
preempt_enable();
}
-static inline long percpu_counter_read(struct percpu_counter *fbc)
+static inline s64 percpu_counter_read(struct percpu_counter *fbc)
{
return fbc->count;
}
-static inline long percpu_counter_read_positive(struct percpu_counter *fbc)
+static inline s64 percpu_counter_read_positive(struct percpu_counter *fbc)
{
return fbc->count;
}
-static inline long percpu_counter_sum(struct percpu_counter *fbc)
+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);
+}
+
#endif /* CONFIG_SMP */
static inline void percpu_counter_inc(struct percpu_counter *fbc)
{
- percpu_counter_mod(fbc, 1);
+ percpu_counter_add(fbc, 1);
}
static inline void percpu_counter_dec(struct percpu_counter *fbc)
{
- percpu_counter_mod(fbc, -1);
+ 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 */