Electrical computers and digital data processing systems: input/ – Input/output data processing – Input/output command process
Patent
1997-07-11
1999-11-23
Lee, Thomas C.
Electrical computers and digital data processing systems: input/
Input/output data processing
Input/output command process
710 39, 711112, 711167, G06F 1314
Patent
active
059918250
ABSTRACT:
A method and disk controller for handling missed revolutions in a disk drive having a rotating data media are disclosed. The method is based on a Rotational Positioning Optimization (RPO) algorithm and comprises the steps of: selecting a primary and a secondary command from the queue using the RPO while a current command is being executed; executing the primary command after the current command is completed; if a missed revolution occurs, then aborting the execution of the primary command and executing the secondary command; and repeating the method steps until all the commands in the queue are executed. Preferably, the RPO algorithm is based on a profile of estimated seek times for the commands in the I/O command queue. The method uses a generally aggressive seek time estimate in selecting a primary command and a generally conservative estimate is used for selecting a secondary command. Accordingly, the missed revolutions can be avoided and system performance is improved.
REFERENCES:
patent: 4680703 (1987-07-01), Kriz
patent: 4819151 (1989-04-01), May
patent: 5018063 (1991-05-01), Liu
patent: 5220653 (1993-06-01), Miro
patent: 5408367 (1995-04-01), Emo
patent: 5426736 (1995-06-01), Guineau, III
patent: 5428787 (1995-06-01), Pineau
patent: 5428802 (1995-06-01), Anglin et al.
patent: 5455924 (1995-10-01), Shenoy et al.
patent: 5570332 (1996-10-01), Heath et al.
patent: 5627976 (1997-05-01), McFarland et al.
patent: 5729718 (1998-03-01), Au
patent: 5796992 (1998-08-01), Reif et al.
patent: 5828836 (1998-10-01), Westwick et al.
M. Seltzer et al., "Disk Scheduling Revisited", USENIX--Winter '90.
B. L. Worthington et al., "Scheduling Algorithms for Modern Disk Drives", Sigmetrics 94-May 1994, Santa Clara. CA.
G. Humphrey, "High Performance PCs Use SCCI", Computer Technology Review, Nov. 1996.
International Business Machines - Corporation
Lee Thomas C.
Park Zlwoo
Tran Khanh Q.
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