ring_buffer_subbuf_order_get
int ring_buffer_subbuf_order_get(struct trace_buffer *buffer);
EXPORT_SYMBOL_GPL(ring_buffer_subbuf_order_get);
order = ring_buffer_subbuf_order_get(tr->array_buffer.buffer);
old_order = ring_buffer_subbuf_order_get(tr->array_buffer.buffer);
order = ring_buffer_subbuf_order_get(tr->array_buffer.buffer);