Before this change scylla-bench was distributing rows among threads correctly only when number of partitions was divisible by number of threads without remainder.
A bit worse case was appearing when there was division remainder.
And the worst case was when number of threads was bigger than number of partitions. In this case last thread was handling all of the rows and all of other threads were idle.
So, fix it by spreading rows evenly among all of the threads as much as possible.
Before this change scylla-bench was distributing rows among threads correctly only when number of partitions was divisible by number of threads without remainder.
A bit worse case was appearing when there was division remainder.
And the worst case was when number of threads was bigger than number of partitions. In this case last thread was handling all of the rows and all of other threads were idle.
So, fix it by spreading rows evenly among all of the threads as much as possible.
Closes: #138