+.. option:: cmdprio_bssplit=str[,str] : [io_uring] [libaio]
+ To get a finer control over I/O priority, this option allows
+ specifying the percentage of IOs that must have a priority set
+ depending on the block size of the IO. This option is useful only
+ when used together with the :option:`bssplit` option, that is,
+ multiple different block sizes are used for reads and writes.
+ The format for this option is the same as the format of the
+ :option:`bssplit` option, with the exception that values for
+ trim IOs are ignored. This option is mutually exclusive with the
+ :option:`cmdprio_percentage` option.
+