12345678910111213141516171819202122232425262728293031323334353637383940414243444546 |
- /*
- * Fast batching percpu counters.
- */
- #include <linux/percpu_counter.h>
- #include <linux/module.h>
- void percpu_counter_mod(struct percpu_counter *fbc, s32 amount)
- {
- long count;
- s32 *pcount;
- int cpu = get_cpu();
- pcount = per_cpu_ptr(fbc->counters, cpu);
- count = *pcount + amount;
- if (count >= FBC_BATCH || count <= -FBC_BATCH) {
- spin_lock(&fbc->lock);
- fbc->count += count;
- *pcount = 0;
- spin_unlock(&fbc->lock);
- } else {
- *pcount = count;
- }
- put_cpu();
- }
- EXPORT_SYMBOL(percpu_counter_mod);
- /*
- * Add up all the per-cpu counts, return the result. This is a more accurate
- * but much slower version of percpu_counter_read_positive()
- */
- s64 percpu_counter_sum(struct percpu_counter *fbc)
- {
- s64 ret;
- int cpu;
- spin_lock(&fbc->lock);
- ret = fbc->count;
- for_each_possible_cpu(cpu) {
- s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
- ret += *pcount;
- }
- spin_unlock(&fbc->lock);
- return ret < 0 ? 0 : ret;
- }
- EXPORT_SYMBOL(percpu_counter_sum);
|