| US 7,464,250 B2 | ||
| Method to reduce disk access time during predictable loading sequences | ||
| Richard Alan Dayan, Raleigh, N.C. (US); and James Franklin Macon, Jr., Raleigh, N.C. (US) | ||
| Assigned to International Business Machines Corporation, Armonk, N.Y. (US) | ||
| Filed on Mar. 11, 2004, as Appl. No. 10/798,091. | ||
| Prior Publication US 2005/0204095 A1, Sep. 15, 2005 | ||
| Int. Cl. G06F 9/06 (2006.01) | ||
| U.S. Cl. 711—217 [711/112; 711/173; 711/213; 711/218] | 1 Claim |
| 1. A method of loading data from disk in a data processing system, comprising:
comparing a current sequence of disk requests to data indicative of a previous sequence of disk requests, wherein the sequence
of disk requests includes the sequence of disk requests following a power-on event;
responsive to detecting a match between the current sequence and the previous sequence, storing a copy of data blocks accessed
during the current sequence in a contiguous portion of the disk, wherein storing a copy of data blocks accessed during the
I/O sequence comprises storing the data blocks sequentially in the order that the data blocks were accessed chronologically;
and
responsive to a subsequent request for data in the disk sequence, mapping the request to the sequential portion of the disk
and servicing the request from data in the sequential portion;
wherein the contiguous portion of the disk to which the data is copied is on a different partition of the disk than a disk
partition on which the original data is stored;
recording a sequence of disk accesses, wherein recording the sequence includes recording the disk address of each block accessed
and the length of each block;
responsive to retrieving data from the contiguous portion, prefetching additional data from the contiguous portion of the
disk and caching the additional data in a buffer; and
responsive to an I/O request, determining whether the data requested resides in the buffer and, if so, retrieving the data
from the buffering without accessing the hard disk.
|