consumer_thread
if (!bench->consumer_thread) {
bench->consumer_thread, (void *)(long)i);
void *(*consumer_thread)(void *ctx);
.consumer_thread = ringbuf_libbpf_consumer,
.consumer_thread = ringbuf_custom_consumer,
.consumer_thread = perfbuf_libbpf_consumer,
.consumer_thread = perfbuf_custom_consumer,
.consumer_thread = consumer,
err = pthread_create(&pt[idx], NULL, consumer_thread, (void *) idx);