A computer system includes a read ahead engine that receives a sequence of read
requests and performs read ahead operations in accordance with various patterns
detected within the sequence of read requests. The prefetch engine may implement
the method of storing a first run value indicative of the run size of a first plurality
of sequential read requests, and storing a first skip value indicative of a non-sequential
skip associated with a subsequent read request. The method may further include
determining whether a second run value indicative of the sequential run size of
a second plurality of read requests equals the first run value, and whether a second
skip value indicative of another non-sequential skip associated with an additional
read request equals the first skip value. If the first run value equals the second
run value, and the first skip value equals the second skip value, a stride pattern
is indicated, and one or more read ahead operations according to the detected stride
pattern may be initiated.
