Dedicated input/output processor method and apparatus for access and storage ...

US006317747B1

(12) United States Patent

Bolan et al.

(io) Patent No.: (45) Date of Patent:

US 6,317,747 Bl *Nov. 13,2001

(54) DEDICATED INPUT/OUTPUT PROCESSOR METHOD AND APPARATUS FOR ACCESS AND STORAGE OF COMPRESSED DATA

(75) Inventors: Joseph Edward Bolan, Vestal, NY (US); Brian Eldridge Clark, Rochester, MN (US); Gregory Robert Klouda, Endwell, NY (US); Bruce Marshall Walk, Rochester, MN (US)

(73) Assignee: International Business Machines Corporation, Armonk, NY (US)

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

This patent is subject to a terminal disclaimer.

(21) Appl. No.: 09/617,198

(22) Filed: Jul. 17, 2000

Related U.S. Application Data

(62) Division of application No. 08/964,292, filed on Nov. 4, 1997, now Pat. No. 6,092,071.

(51) Int. C I. G06F 13/00

(52) U.S. CI 707/101; 707/204; 710/68

(58) Field of Search 707/101, 204,

707/200, 203, 205, 206; 710/68, 65; 340/232;

341/51, 107

(56) References Cited

U.S. PATENT DOCUMENTS

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(List continued on next page.)

System control ol compression and decompression ol data based upon system aging parameters, such that compressed data becomes a system managed resource with a distinct place in the system storage hierarchy. Processor registers are backed by cache, which is backed by main storage, which is backed by decompressed disk storage, which is backed by compressed disk storage then tape, and so forth. Data is moved from decompressed to compressed form and migrated through the storage hierarchy under system control according to a data life cycle based on system aging parameters or, optionally, on demand: data is initially created and stored; the data is compressed at a later time under system control; when the data is accessed, it is decompressed on demand by segment; at some later time, the data is again compressed under system control until next reference. Large data objects are segmented and compression is applied to more infrequently used data. A dedicated compression input/ output processor (IOP) is controlled by host system defined data structures which include a bus transport mechanism (BTM) which is DMA loaded to the compression IOP storage. The BTM includes a request response control block (RRCB) comprising a compress or decompress operation command, a data out descriptor (DOD) for providing the address of data in host storage that needs to be compressed or decompressed, and data in descriptor (DID) for providing the address in host storage where the resulting decompressed or compressed data is to be stored.

5 Claims, 12 Drawing Sheets

Page 2

U.S. PATENT DOCUMENTS

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