diff options
| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:01 +0000 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:01 +0000 |
| commit | 7996a3d79d55b7f879dfd62e202bbfe2963718d3 (patch) | |
| tree | 8d9f6759fec4099b9be503c11c7ed174f7204980 /libdde-linux26/include/linux/percpu_counter.h | |
| parent | 4fbe7358c7747a9165f776eb19addbb9baf7def2 (diff) | |
really properly move files
Diffstat (limited to 'libdde-linux26/include/linux/percpu_counter.h')
| -rw-r--r-- | libdde-linux26/include/linux/percpu_counter.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/libdde-linux26/include/linux/percpu_counter.h b/libdde-linux26/include/linux/percpu_counter.h new file mode 100644 index 00000000..c1f9482f --- /dev/null +++ b/libdde-linux26/include/linux/percpu_counter.h @@ -0,0 +1,149 @@ +#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> + +#if defined(CONFIG_SMP) && !defined(DDE_LINUX) + +struct percpu_counter { + spinlock_t lock; + s64 count; +#ifdef CONFIG_HOTPLUG_CPU + struct list_head list; /* All percpu_counters are on a list */ +#endif + s32 *counters; +}; + +extern int percpu_counter_batch; + +int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, + struct lock_class_key *key); + +#define percpu_counter_init(fbc, value) \ + ({ \ + static struct lock_class_key __key; \ + \ + __percpu_counter_init(fbc, value, &__key); \ + }) + +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) +{ + __percpu_counter_add(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 1; +} + +#else + +struct percpu_counter { + s64 count; +}; + +static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount) +{ + 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; +} + +#define __percpu_counter_add(fbc, amount, batch) \ + percpu_counter_add(fbc, amount) + +static inline void +percpu_counter_add(struct percpu_counter *fbc, s64 amount) +{ + preempt_disable(); + fbc->count += amount; + preempt_enable(); +} + +static inline s64 percpu_counter_read(struct percpu_counter *fbc) +{ + return fbc->count; +} + +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); +} + +#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 */ |