ring_buffer_subbuf_order_set
int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order);
EXPORT_SYMBOL_GPL(ring_buffer_subbuf_order_set);
ret = ring_buffer_subbuf_order_set(tr->array_buffer.buffer, order);
ret = ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, order);
cnt = ring_buffer_subbuf_order_set(tr->array_buffer.buffer, old_order);
ret = ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, order);
ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, 0);