Depending on the desired embodiment, the re-evaluation performed in operation 504 may include a number of operations. The order in which some of the operations are performed may also vary depending on the particular approach. Referring now specifically to the operations and decisions outlined in re-evaluation operation 504, an exemplary flowchart of processes which may be performed during the re-evaluation process of a unit of memory is presented, but is in no way intended to be limited thereto. Moreover, any combination of such operations and/or decisions may be implemented and/or omitted in a particular embodiment. The operations and decisions outlined in re-evaluation operation 504 may be used to determine whether the corresponding unit of memory should be retired (e.g., permanently) or reused as described above.

Referring still to FIG. 5, upon determining that a unit of memory (e.g., at least one block and/or a portion of a block) meets a retirement condition, method 500 proceeds to decision 552. Decision 552 includes determining whether there is an adequate amount of free space in a delay queue to accommodate the unit of memory, e.g., to perform a re-evaluation thereof. When it is determined that an adequate amount of free space does not exist in the delay queue, method 500 advances directly from decision 552 to operation 508 which includes indicating that the unit of memory is retired. Thus, a lack of free space in the delay queue may result in the automatic retirement of units of memory that may otherwise successfully pass the re-evaluation of operation 504 and remain usable. It follows that an adequate amount of free space in the delay queue is desirable.