Patent ID: 6272565
Filing Date: 2001-08-07
Classification: G06F

Abstract:
A method for selecting an input/output (I/O) command in a queue of I/O commands, wherein each command operates within a range of addressable locations on a storage medium, and wherein each of the addressable locations is defined according to at least a sector number and track number, comprising:providing a plurality of buckets, wherein each bucket represents a range of consecutive sector numbers, and wherein the queued I/O commands are associated with a bucket such that a sector number of an addressable location in which an I/O command operates is within the range of consecutive sector numbers comprising the associated bucket;determining a reference position;executing a selection routine to select an I/O command to execute against the storage medium by performing:(i) selecting a bucket including at least one I/O command;(ii) selecting an I/O command within the selected bucket;(iii) determining whether the selected I/O command meets a selection criteria based on the reference position;(iv) indicating the selected I/O command as the I/O command to process after determining that the selected I/O command meets the selection criteria; and(v) performing another iteration of the selection routine after determining that the selected I/O command does not meet the selection criteria.