When writing my new hdfs engine, I met a problem with IO merge. If I submit IO that are bigger that what the hdfs can manage, I return them to fio as incomplete IO, the net engine works the same way : in engines/net.c, line 668+ io_u->resid = io_u->xfer_buflen - ret; io_u->error = 0; return FIO_Q_COMPLETED; But the fio count them as two or more fast IO. I'm not sure it's a good measurement because if I'm simulating an application with fio, I expect to get the full IO latency and operations/s count. I don't mesure to mesure sub-io for that. For example, reducing the maximum transfer size will increase IO/s and reduce latency, even if the simulated application really sees reduced performance, because more of it's high level IO operation generated more real IO. Is there a way to prevent that in fio, or is that up to my engine to manage that and merge IO ?-- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
