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US 8,078,901 B1Granted
Method for increasing a processor operating frequency when other subsystem demands are low
AssigneeWestern Digital Technologies, Inc.
InventorsAlan T. Meyer, Kenny T. Coker
Life of this patent
Estimating the term…
Abstract
A host activity measure indicative of a frequency of disk access commands received by a disk drive is determined, and then compared against a host activity threshold. A subsystem activity measure indicative of an activity level of a disk drive subsystem is also determined, and then compared against a subsystem activity threshold. Based at least in part on a determination that 1) the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and 2) the subsystem activity measure is indicative of less activity than the subsystem activity threshold, an operating frequency of a disk drive processor is increased.
Claims28
A method of operating a disk drive having a processor and a first disk drive subsystem, the method comprising:
- determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer;
- comparing the host activity measure against a host activity threshold;
- determining a first subsystem activity measure indicative of an activity level of the first subsystem;
- comparing the first subsystem activity measure against a first subsystem activity threshold;
- determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- and
- increasing an operating frequency of the processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold, wherein the first subsystem includes a servo subsystem of the disk drive, and wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the servo subsystem for a seek operation.
4 more elements
A method of operating a disk drive having a processor and a first disk drive subsystem, the method comprising:
- determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer that includes an average time interval between completed disk access commands based on logging a plurality of time intervals in a circular buffer, each of the plurality of time intervals indicative of time elapsed between consecutive completed disk access commands and calculating an average of the plurality of time intervals wherein the circular buffer has 2k time intervals logged therein, and calculating the average of the plurality of time intervals includes shifting a sum of the plurality of time intervals by k;
- comparing the host activity measure against a host activity threshold;
- determining a first subsystem activity measure indicative of an activity level of the first subsystem;
- comparing the first subsystem activity measure against a first subsystem activity threshold;
- determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- and
- increasing an operating frequency of the processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold.
4 more elements
A method of operating a disk drive having a processor and a first disk drive subsystem, the method comprising:
- determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer that includes an average time interval between completed disk access commands, wherein determining the host activity measure includes passing a time interval indicative of time elapsed between consecutive completed disk access commands through an infinite impulse response low pass filter;
- comparing the host activity measure against a host activity threshold;
- determining a first subsystem activity measure indicative of an activity level of the first subsystem;
- comparing the first subsystem activity measure against a first subsystem activity threshold;
- determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- and
- increasing an operating frequency of the processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold.
4 more elements
A method of operating a disk drive having a processor and a first disk drive subsystem, the method comprising:
- determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer;
- comparing the host activity measure against a host activity threshold;
- determining a first subsystem activity measure indicative of an activity level of the first subsystem;
- comparing the first subsystem activity measure against a first subsystem activity threshold;
- determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- and
- increasing an operating frequency of the processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold, wherein the first subsystem includes a channel subsystem of the disk drive, and wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the channel subsystem for a read or write operation and wherein determining the first subsystem activity measure includes
- logging a plurality of time intervals in a circular buffer, each of the plurality of time intervals indicative of time elapsed between consecutive operations of arming the channel subsystem and
- calculating an average of the plurality of time intervals.
6 more elements
A method of operating a disk drive having a processor and a first disk drive subsystem, the method comprising:
- determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer;
- comparing the host activity measure against a host activity threshold;
- determining a first subsystem activity measure indicative of an activity level of the first subsystem;
- comparing the first subsystem activity measure against a first subsystem activity threshold;
- determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- and
- increasing an operating frequency of the processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold, wherein the first subsystem includes a channel subsystem of the disk drive, wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the channel subsystem for a read or write operation, and wherein determining the first subsystem activity measure includes passing a time interval indicative of time elapsed between consecutive operations of arming the channel subsystem through an infinite impulse response low pass filter.
4 more elements
A method of operating a disk drive having a processor and a first disk drive subsystem, the method comprising:
- determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer;
- comparing the host activity measure against a host activity threshold;
- determining a first subsystem activity measure indicative of an activity level of the first subsystem;
- comparing the first subsystem activity measure against a first subsystem activity threshold;
- determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- increasing an operating frequency of the processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- determining a second subsystem activity measure indicative of an activity level of a second disk drive subsystem;
- comparing the second subsystem activity measure against a second subsystem activity threshold;
- and
- determining that the second subsystem activity measure is indicative of less activity than the second subsystem activity threshold.
7 more elements
A disk drive comprising:
- a disk having a disk surface;
- a head actuatable over the disk surface and operable to write and read from the disk surface;
- a host interface configured to receive disk access commands from a host computer coupled to the disk drive, the disk access commands being associated with a host activity measure indicative of a frequency of the disk access commands;
- a first subsystem associated with a first subsystem activity measure indicative of an activity level of the first subsystem, wherein the first subsystem includes a servo subsystem of the disk drive;
- a processor configured to operate at an operating frequency;
- and
- a clock coupled to the processor and configured to generate an adjustable timing signal to control the operating frequency, the clock operable to increase the operating frequency based at least in part on the host activity measure being indicative of a greater frequency of disk access commands than a host activity threshold, and the first subsystem activity measure being indicative of less activity than a first subsystem activity threshold, wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the servo subsystem for a seek operation.
4 more elements
A disk drive comprising:
- a disk having a disk surface;
- a head actuatable over the disk surface and operable to write and read from the disk surface;
- a host interface configured to receive disk access commands from a host computer coupled to the disk drive, the disk access commands being associated with a host activity measure indicative of a frequency of the disk access commands;
- a first subsystem associated with a first subsystem activity measure indicative of an activity level of the first subsystem;
- a processor configured to operate at an operating frequency;
- a clock coupled to the processor and configured to generate an adjustable timing signal to control the operating frequency, the clock operable to increase the operating frequency based at least in part on the host activity measure being indicative of a greater frequency of disk access commands than a host activity threshold, and the first subsystem activity measure being indicative of less activity than a first subsystem activity threshold, wherein the host activity measure includes an average time interval between completed disk access commands;
- and
- an infinite impulse response lowpass filter configured to filter a time interval indicative of time elapsed between consecutive completed disk access commands.
5 more elements
A disk drive comprising:
- a disk having a disk surface;
- a head actuatable over the disk surface and operable to write and read from the disk surface;
- a host interface configured to receive disk access commands from a host computer coupled to the disk drive, the disk access commands being associated with a host activity measure indicative of a frequency of the disk access commands;
- a first subsystem associated with a first subsystem activity measure indicative of an activity level of the first subsystem, wherein the first subsystem includes a channel subsystem of the disk drive;
- a processor configured to operate at an operating frequency;
- a clock coupled to the processor and configured to generate an adjustable timing signal to control the operating frequency, the clock operable to increase the operating frequency based at least in part on the host activity measure being indicative of a greater frequency of disk access commands than a host activity threshold, and the first subsystem activity measure being indicative of less activity than a first subsystem activity threshold, wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the channel subsystem for a read or write operation;
- and
- a circular buffer operable to log a plurality of time intervals, each of the plurality of time intervals indicative of time elapsed between the consecutive operations of arming the channel system.
5 more elements
A disk drive comprising:
- a disk having a disk surface;
- a head actuatable over the disk surface and operable to write and read from the disk surface;
- a host interface configured to receive disk access commands from a host computer coupled to the disk drive, the disk access commands being associated with a host activity measure indicative of a frequency of the disk access commands;
- a first subsystem associated with a first subsystem activity measure indicative of an activity level of the first subsystem, wherein the first subsystem includes a channel subsystem of the disk drive;
- a processor configured to operate at an operating frequency;
- a clock coupled to the processor and configured to generate an adjustable timing signal to control the operating frequency, the clock operable to increase the operating frequency based at least in part on the host activity measure being indicative of a greater frequency of disk access commands than a host activity threshold, and the first subsystem activity measure being indicative of less activity than a first subsystem activity threshold, wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the channel subsystem for a read or write operation;
- and
- an infinite impulse response lowpass filter operable to filter a time interval indicative of time elapsed between consecutive operations or arming the channel subsystem.
5 more elements
A disk drive comprising:
- a disk having a disk surface;
- a head actuatable over the disk surface and operable to write and read from the disk surface;
- a host interface configured to receive disk access commands from a host computer coupled to the disk drive, the disk access commands being associated with a host activity measure indicative of a frequency of the disk access commands;
- a first subsystem associated with a first subsystem activity measure indicative of an activity level of the first subsystem;
- a processor configured to operate at an operating frequency;
- and
- a clock coupled to the processor and configured to generate an adjustable timing signal to control the operating frequency, the clock operable to increase the operating frequency based at least in part on the host activity measure being indicative of a greater frequency of disk access commands than a host activity threshold, and the first subsystem activity measure being
- indicative of less activity than a first subsystem activity threshold;
- and
- a second subsystem associated with a second subsystem activity measure indicative of an activity level of the second subsystem, and wherein the clock is further operable to increase the operating frequency based at least in part on the second subsystem activity measure being indicative of less activity than a second subsystem activity threshold.
7 more elements
A disk drive comprising:
- means for determining a host activity measure indicative of a frequency of disk access commands received by the disk drive from a host computer;
- means for comparing the host activity measure against a host activity threshold;
- means for determining a first subsystem activity measure indicative of an activity level of a first disk drive subsystem, wherein the first subsystem includes a servo subsystem of the disk drive;
- means for comparing the first subsystem activity measure against a first subsystem activity threshold;
- means for determining that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold;
- and
- means for increasing an operating frequency of a processor based at least in part on the determination that the host activity measure is indicative of a greater frequency of disk access commands than the host activity threshold, and that the first subsystem activity measure is indicative of less activity than the first subsystem activity threshold, wherein the first subsystem activity measure is an average time interval between consecutive operations of arming the servo subsystem for a seek operation.
4 more elements
Dependencies are inferred from the claim text.