Timing data will be stored in a shared memory area. In this example, the size of this memory is set to 64 KB. If you decrease the mdriver_max value from 16 KB to a lower value, then you may need to increase this 64 KB value (e.g. to 128 KB). This is due to a larger number of callouts made when mdriver_max is decreased.
You should use the default mdriver_max value of 16 KB. So, the data storage required will be 64 KB. The assumption here is that there is no hardware access required for this implementation.