static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
{
	unsigned long sum  = 0;
	int cpu;
	int len;
	int *data = kmalloc_array(nr_cpu_ids, sizeof(int), GFP_KERNEL);

	if (!data)
		return -ENOMEM;

	for_each_online_cpu(cpu) {
		unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];

		data[cpu] = x;
		sum += x;
	}

	len = sprintf(buf, "%lu", sum);

#ifdef CONFIG_SMP
	for_each_online_cpu(cpu) {
		if (data[cpu] && len < PAGE_SIZE - 20)
			len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
	}
#endif
	kfree(data);
	return len + sprintf(buf + len, "\n");
}