+ struct ring_buffer_event *e;
+ e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL);
+ if (e)
+ return ring_buffer_event_data(e);
+ if (ring_buffer_swap_cpu(op_ring_buffer_read,
+ op_ring_buffer_write,
+ cpu))
+ return NULL;
+ e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL);
+ if (e)
+ return ring_buffer_event_data(e);
+ return NULL;