ring_buffer_time_stamp
u64 ring_buffer_time_stamp(struct trace_buffer *buffer);
EXPORT_SYMBOL_GPL(ring_buffer_time_stamp);
ts = ring_buffer_time_stamp(buf->buffer);
return ring_buffer_time_stamp(buffer);
t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer));
ring_buffer_time_stamp(trace_buf->buffer));
ring_buffer_time_stamp(tr->array_buffer.buffer);