[RFC] Non-repeating file_service_type: roundrobin1 and random1

[koct9i]

These servicing modes does not repeat file until completion previous operation.

( i.e. when nrfiles > iodepth fio should chose files which has no in-flight I/O )

Streaming IO-engines might not handle several requests to one "file" at once. Or such workload might not match any real scenarios.

Signed-off-by: Konstantin Khlebnikov [email protected]

Reminders:

1. If you modify struct thread_options, also make corresponding changes in cconv.c and bump FIO_SERVER_VER in server.h
2. If you change the ioengine interface (hooks, flags, etc), remember to bump FIO_IOOPS_VERSION in ioengines.h.

// Ok, will do later if this change is ok