Dynamic memory allocation for assigning partitions to a logical port from two groups of un-assigned partitions based on two threshold values

A memory is divided into a number of partitions. The partitions are grouped into a first group of partitions and a second group of partitions. When required by a port, a partition is assigned to the port from a pool of un-assigned partitions. The pool of un-assigned partitions comprises of un-assigned partitions from the first group of partitions and un-assigned partitions from the second group of partitions. The un-assigned partitions from the first group of partitions are assigned to the port until a first threshold is reached. The un-assigned partitions from the second group of partitions are assigned to the port after the first threshold is reached. A second threshold is used to limit a total number of partitions assigned to the port.