``flow=8`` and another job has ``flow=-1``, then there will be a roughly 1:8
ratio in how much one runs vs the other.
-.. option:: flow_watermark=int
-
- The maximum value that the absolute value of the flow counter is allowed to
- reach before the job must wait for a lower value of the counter.
-
.. option:: flow_sleep=int
- The period of time, in microseconds, to wait after the flow watermark has
- been exceeded before retrying operations.
+ The period of time, in microseconds, to wait after the flow counter
+ has exceeded its proportion before retrying operations.
.. option:: stonewall, wait_for_previous