/* * 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);