Power efficient media playback on general purpose portable devices

• US 20070226417A1
• Filed: 03/23/2006
• Published: 09/27/2007
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Davis, Darren
• Granted Patent: US 8,099,548 B2
• Time in Patent Office: Days
• US Class Current: 711/118
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 2212/601 Reconfiguration of cache memory
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A portable multifunction computing device optimizes cache storage when processing media files and the like. During a playback operation, the device caches as many media items as possible such that during playback media items are retrieved from cache rather than from a hard disk memory. The device monitors memory requirements of other programs and applications currently in use on the device to insure sufficient cache memory is available for such programs and applications.

Claims

1. A method of managing memory for optimizing performance of a multifunction portable computing device, said method comprising:

receiving at least one cache request from an application being executed by the computing device, said cache request specifying data to be cached;

defining a memory area of the computing device for caching during execution of the application, said memory area comprising a plurality of segments, said segments each having a storage capacity available for caching;

allocating one or more of the segments for caching the data specified by the cache request; and

retrieving cached data from the one or more segments for processing by the application.

2. The method of claim 1 further comprising determining, based on the cache request, whether the computing device has sufficient memory for caching the data specified by the cache request before allocating the one or more segments for caching.

3. The method of claim 2 further includes generating a pending cache request for the data specified by the cache request when the determining indicates the computing device does not have sufficient memory for caching the specified data.

4. The method of claim 3 further comprising monitoring the plurality of segments to identify when at least one of plurality of segments has the sufficient storage capacity available for storing the specified data in response to the pending cache request.

5. The method of claim 1, wherein the receiving includes receiving a memory usage event from one or more different application being executed by the computing device, said memory usage event specifying a current memory state of the computing device and indicating whether additional memory is required by the one or more different applications to perform their operations.

6. The method of claim 5, wherein the received memory usage event is one or more of the following:

a memory need event indicating that the device has reached a state in which requests for large amounts of memory may no longer be fulfilled because memory is not available;

a memory full event indicating that the amount of available memory is not generally sufficient for standard operation; and

a memory critical event indicating the amount of available memory is below a critical threshold level.

7. The method of claim 5 further including adjusting the memory area available for caching, wherein said adjusting includes:

allocating a portion of the memory area back to a memory system of the device when at least two of the plurality of segments are allocated for caching the data specified by the cache request;

or

allocating a portion of the memory area back to the memory system of the device when only one of the plurality of segments is allocated for caching the data specified by the cache request.

8. The method of claim 1, wherein the storage capacity of each of the plurality of segments is fixed, and wherein the number of segments in the plurality of segments is determined by the amount of memory requested by the cache request.

9. The method of claim 8, wherein the allocating includes allocating a different one or more of the segments for caching the different data specified by the cache request when the determining indicates the computing device has sufficient memory available for caching the different data.

10. The method of claim 8 further comprising identifying one or more of the plurality of segments caching data specified by the cache request that is not currently being processed by the application, and reallocating the identified one or more of the segments for caching the different data specified by the subsequent cache request when the determining indicates the computing device has sufficient memory available for caching the different data.

11. The method of claim 1 further comprising monitoring the plurality of segments to identify one or more of the plurality of segments caching the data that has been processed by the application, and removing the processed data from the identified one or more segments.

12. One or more computer-readable media having computer executable components executed by a multifunction portable computing device for optimizing performance of the portable computing device, said computer-readable media comprising:

a defining component for defining a memory area of the computing device for caching during execution of the application, said memory area comprising a plurality of segments, said segments each having a predetermined storage capacity available for caching;

a cache management component for receiving at least one cache request from an application being executed by the computing device, said cache request specifying data to be cached, and said a cache management component determining, based on the cache request, whether the computing device has sufficient memory for caching the specified data; and

a consumption component for allocating one or more of the segments for caching the specified data when the computing device is determined to have sufficient memory for caching the data specified by the cache request.

13. The computer-readable media of claim 12, wherein the cache management component is further configured for generating a pending cache request for the specified data when the cache management component indicates the computing device does not have sufficient memory for caching the specified data.

14. The computer-readable media of claim 12, wherein the cache management component is configured for receiving at least one subsequent cache request, said subsequent cache request specifying different data to be cached, and wherein the cache management component is further configured for determining, based on the subsequent cache request, whether the computing device has sufficient memory available for caching the different specified data.

15. The computer-readable media of claim 14, wherein the consumption component is configured for allocating a different one or more of the segments for caching the different specified data when the cache management component indicates the computing device has sufficient memory available for caching the different specified data.

16. The computer-readable media of claim 14, wherein consumption component is further configured for:

retrieving cached data from the one or more segments for processing by the application;

identifying one or more of the plurality of segments caching data that is not currently being processed by the application; and

reallocating the identified one or more of the segments for caching the different specified data when the determining indicates the computing device has sufficient memory available for caching the different specified data.

17. The computer-readable media of claim 16, wherein the consumption component is further configured for monitoring the plurality of segments to identify one or more of the plurality of segments caching data that has been processed by the application and removing the processed data from the identified one or more segments.

18. A portable computing device comprising:

an user interface, associated with the portable computing device, for generating a cache request in response to input from a user, said cache request specifying data to be cached;

a processor, associated with the portable computing device, for executing computer-executable instructions for;

defining a memory area of the computing device for caching during execution of the application, said memory area comprising a plurality of segments, said segments each having a predetermined storage capacity available for caching;

determining, based on the cache request, whether the computing device has sufficient memory for caching the specified data before allocating the one or more segments for caching;

allocating one or more of the segments for caching the specified data when the computing device is determined to have sufficient memory for caching the data specified by the cache request; and

retrieving cached data from the one or more segments for processing by the application.

19. The device of claim 18, wherein the processor further executes computer-executable instructions for:

monitoring the plurality of segments to identify one or more of the plurality of segments caching data that has been processed by the application; and

removing the processed data from the identified one or more segments.

20. The device of claim 18, wherein defining a memory area further includes partitioning a memory area into a caching memory portion, a reserve memory portion, and a critical memory portion, wherein the caching memory portion has a predetermined storage capacity available for caching, and wherein the reserve memory portion has a predetermined storage capacity available for additional caching, and wherein the critical memory portion has a predetermined storage capacity available for supporting an operating system executing on the portable computing device, and wherein at least a portion of the storage capacity of the reserve memory portion is allocated to the critical memory portion during a memory critical event