Patents by Inventor Adam Michael Espeseth
Adam Michael Espeseth has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7334081Abstract: An RPO algorithm in a HDD coalesces LBA-sequential XOR commands in pipes, and passes the pipes to a lower level execution engine. The execution engine executes XOR reads and write separately to optimize performance using head and/or cylinder skew information to approach the nominal disk data rate.Type: GrantFiled: April 29, 2005Date of Patent: February 19, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Adam Michael Espeseth, Edward Henry Younk
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Patent number: 7254525Abstract: A method and apparatus is provided which reduces the equipment and time requirements for hard disk drive performance testing during manufacturing. This invention executes self-contained performance testing code that resides within the drive's manufacturing firmware, rather than relying on external testers. The invention involves exercising the drive's enqueue, dequeue, and command execution firmware, as well as the physical process of reading and writing data by simulating the host interface in code. The invention enqueues commands that typify the desired workload, allows a command ordering algorithm to sort the commands for execution, and allows the drive side code to execute the commands just as if an external host interface were attached. The invention is advantageous because the performance testing can be done by only applying power to the drive. The present invention also lends itself to performance tuning that can be done in manufacturing, to reduce drive-to-drive performance variations.Type: GrantFiled: October 17, 2002Date of Patent: August 7, 2007Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Trevor James Briggs, Adam Michael Espeseth, Robert Anton Steinbach, Christopher David Wiederholt
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Patent number: 6965965Abstract: The present invention provides a method, apparatus and article of manufacture for selecting commands to execute from a command queue in a data storage device. The present invention reduces maximum service times under random queued workloads by executing the oldest command in the queue at a constant and predetermined rate. This yields a minimal yet predictable performance penalty, while significantly reducing maximum service times.Type: GrantFiled: June 6, 2002Date of Patent: November 15, 2005Assignee: International Business Machines CorporationInventors: Adam Michael Espeseth, David Robison Hall
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Patent number: 6877070Abstract: A method and apparatus are provided for implementing command queue ordering with benefit determination of a prefetch operation. For each command in a hard disk drive command queue, a rotational position optimization (RPO) score is calculated. A prefetch benefit is calculated for each command in the hard disk drive command queue within a working partition. The RPO score is modified utilizing the calculated prefetch benefit for the commands in the hard disk drive command queue within the working partition. A best RPO score is identified to select a next command in the hard disk drive command queue to execute.Type: GrantFiled: July 23, 2002Date of Patent: April 5, 2005Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Adam Michael Espeseth, David Robison Hall
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Patent number: 6809896Abstract: An adaptive maximum seek velocity clipping technique is employed in a disk drive to reduce head movement power requirements. Separate maximum seek velocities are established for respective categories of access commands, where the categories are defined by seek distance and estimated extra latency. The maximum seek velocity established for each category of access commands reflects actual experience in executing access commands of the given category. The maximum seek velocity values for the various categories are stored in a maximum seek velocity table, which is referred to upon execution of access commands. The inventive power-saving technique may be advantageously applied in conjunction with a probability-based shortest access time first (SATF) command queue ordering algorithm.Type: GrantFiled: March 14, 2002Date of Patent: October 26, 2004Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Adam Michael Espeseth, David Robison Hall, Maile Matsui Vasoli
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Patent number: 6804751Abstract: A command queue is maintained in a disk drive. The command queue includes a plurality of access commands that are awaiting execution. The command queue is sorted to provisionally select one of the plurality of access commands as the next command to be executed. A seek start deadline is calculated for the provisionally selected access command based on an estimated extra latency of the provisionally selected access command. A seek operation with respect to the provisionally selected access command is deferred based on the calculated seek start deadline, to await arrival at the disk drive of a new access command. If the new access command arrives at the disk drive prior to the seek start deadline, the respective estimated access times for the provisionally selected access command and the newly arrived access command are compared to select one of the two access commands for execution.Type: GrantFiled: March 20, 2002Date of Patent: October 12, 2004Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Adam Michael Espeseth, David Robison Hall, James R. Shipman
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Publication number: 20040078185Abstract: A method and apparatus is provided which reduces the equipment and time requirements for hard disk drive performance testing during manufacturing. This invention executes self-contained performance testing code that resides within the drive's manufacturing firmware, rather than relying on external testers. The invention involves exercising the drive's enqueue, dequeue, and command execution firmware, as well as the physical process of reading and writing data by simulating the host interface in code. The invention enqueues commands that typify the desired workload, allows a command ordering algorithm to sort the commands for execution, and allows the drive side code to execute the commands just as if an external host interface were attached. The invention is advantageous because the performance testing can be done by only applying power to the drive. The present invention also lends itself to performance tuning that can be done in manufacturing, to reduce drive-to-drive performance variations.Type: ApplicationFiled: October 17, 2002Publication date: April 22, 2004Applicant: International Business Machines CorporationInventors: Trevor James Briggs, Adam Michael Espeseth, Robert Anton Steinbach, Christopher David Wiederholt
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Patent number: 6725327Abstract: A method and apparatus are provided for hard disk drive command queue ordering. For each command in the hard disk drive command queue, an expected access time is calculated including a probability of success calculation. A command in the hard disk drive command queue having a minimum calculated expected access time is identified. Then the identified command having a minimum calculated expected access time is executed. For an estimated seek time of less than a time for one full revolution, a probability of a miss multiplied by a time of one extra revolution is calculated and the result is added to an estimated seek time to provide the expected access time. For an estimated seek time of greater than a time for one full revolution, a probability of a make multiplied by a time of one extra revolution is calculated and the result is subtracted from an estimated seek time to provide the expected access time.Type: GrantFiled: August 14, 2000Date of Patent: April 20, 2004Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Adam Michael Espeseth, David Robison Hall, James Joseph Mosser, Steven Glenn Smith
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Publication number: 20040019745Abstract: A method and apparatus are provided for implementing command queue ordering with benefit determination of a prefetch operation. For each command in a hard disk drive command queue, a rotational position optimization (RPO) score is calculated. A prefetch benefit is calculated for each command in the hard disk drive command queue within a working partition. The RPO score is modified utilizing the calculated prefetch benefit for the commands in the hard disk drive command queue within the working partition. A best RPO score is identified to select a next command in the hard disk drive command queue to execute.Type: ApplicationFiled: July 23, 2002Publication date: January 29, 2004Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Adam Michael Espeseth, David Robison Hall
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Patent number: 6681289Abstract: A method and apparatus are provided for efficiently sorting queued commands with unknown rotational latency in a direct access storage device (DASD). For each command an initial expected access time (EAT) including a probability of success calculation is calculated and stored in a miss table. An actual starting location for the next command to be executed is identified. Utilizing the miss table, and a calculated best candidate command list for a plurality of different starting locations, a command in a command queue is selected based upon the actual starting location. The best candidate command list for a plurality of different starting locations is calculated by first sorting the miss table row by increasing EAT values and sequentially incrementing a miss time value by the predefined unit of time and updating all variable in the first row and adjusting a potential value in the second row of the miss table.Type: GrantFiled: January 25, 2002Date of Patent: January 20, 2004Assignee: International Business Machines CorporationInventors: Adam Michael Espeseth, David Robison Hall, Maile Matsui Vasoli
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Publication number: 20030229755Abstract: The present invention provides a method, apparatus and article of manufacture for selecting commands to execute from a command queue in a data storage device. The present invention reduces maximum service times under random queued workloads by executing the oldest command in the queue at a constant and predetermined rate. This yields a minimal yet predictable performance penalty, while significantly reducing maximum service times.Type: ApplicationFiled: June 6, 2002Publication date: December 11, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Adam Michael Espeseth, David Robison Hall
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Patent number: 6640258Abstract: A method and apparatus are provided for hard disk drive command queue ordering. A command received from a host is placed in a rotational order command list. A fraction of the rotational order command list is analyzed. Commands are analyzed with a maximum selection probability. A maximum analysis time before the currently executing command is completed is determined. The total analysis time cannot exceed the maximum analysis time. The fraction of the rotational order command list is analyzed in a first pass. A skip-sort interval is selected based upon the maximum analysis time and a current queue depth of the rotational order command list. In a second pass, the number of commands analyzed corresponds with the number of commands that can be analyzed in the remaining available processing time.Type: GrantFiled: January 10, 2001Date of Patent: October 28, 2003Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Adam Michael Espeseth, David Robison Hall
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Publication number: 20030182499Abstract: A command queue is maintained in a disk drive. The command queue includes a plurality of access commands that are awaiting execution. The command queue is sorted to provisionally select one of the plurality of access commands as the next command to be executed. A seek start deadline is calculated for the provisionally selected access command based on an estimated extra latency of the provisionally selected access command. A seek operation with respect to the provisionally selected access command is deferred based on the calculated seek start deadline, to await arrival at the disk drive of a new access command. If the new access command arrives at the disk drive prior to the seek start deadline, the respective estimated access times for the provisionally selected access command and the newly arrived access command are compared to select one of the two access commands for execution.Type: ApplicationFiled: March 20, 2002Publication date: September 25, 2003Applicant: International Business Machines CorporationInventors: Adam Michael Espeseth, David Robison Hall, James R. Shipman
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Publication number: 20030174433Abstract: An adaptive maximum seek velocity clipping technique is employed in a disk drive to reduce head movement power requirements. Separate maximum seek velocities are established for respective categories of access commands, where the categories are defined by seek distance and estimated extra latency. The maximum seek velocity established for each category of access commands reflects actual experience in executing access commands of the given category. The maximum seek velocity values for the various categories are stored in a maximum seek velocity table, which is referred to upon execution of access commands. The inventive power-saving technique may be advantageously applied in conjunction with a probability-based shortest access time first (SATF) command queue ordering algorithm.Type: ApplicationFiled: March 14, 2002Publication date: September 18, 2003Applicant: International Business Machines CorporationInventors: Adam Michael Espeseth, David Robison Hall, Maile Matsui Vasoli
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Publication number: 20030158996Abstract: A method and apparatus are provided for efficiently sorting queued commands with unknown rotational latency in a direct access storage device (DASD). Simultaneously with executing a current command, for each command in a DASD command queue an initial expected access time (EAT) including a probability of success calculation is calculated and stored together with a plurality of predefined variables in a respective row in a miss table. Utilizing the stored miss table, a best candidate command list for a plurality of different starting locations for a next command to be executed is calculated. An actual starting location for the next command to be executed is identified. Utilizing the best candidate command list for the plurality of different starting locations, a command in a DASD command queue is selected based upon the actual starting location.Type: ApplicationFiled: January 25, 2002Publication date: August 21, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Adam Michael Espeseth, David Robison Hall, Maile Matsui Vasoli
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Publication number: 20020091882Abstract: A method and apparatus are provided for hard disk drive command queue ordering. A command received from a host is placed in a rotational order command list. A fraction of the rotational order command list is analyzed. Commands are analyzed with a maximum selection probability. A maximum analysis time before the currently executing command is completed is determined. The total analysis time cannot exceed the maximum analysis time. The fraction of the rotational order command list is analyzed in a first pass. A skip-sort interval is selected based upon the maximum analysis time and a current queue depth of the rotational order command list. In a second pass, the number of commands analyzed corresponds with the number of commands that can be analyzed in the remaining available processing time.Type: ApplicationFiled: January 10, 2001Publication date: July 11, 2002Applicant: INTERNATIONAL BUSINESS MACHINES COPRORATIONInventors: Adam Michael Espeseth, David Robison Hall