+ rwmixcycle=x Base cycle for switching between read and write
+ in msecs.
+ rwmixread=x 'x' percentage of rw mix ios will be reads. If
+ rwmixwrite is also given, the last of the two will
+ be used if they don't add up to 100%.
+ rwmixwrite=x 'x' percentage of rw mix ios will be writes. See
+ rwmixread.