Method and system for run-time cache logging

• US 20070150881A1
• Filed: 12/22/2005
• Published: 06/28/2007
• Est. Priority Date: 12/22/2005
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Khawand, Charbel, Miller, Jianping
• Application Number:
  US11/315,396
• Publication Number:
  US 20070150881A1
• Time in Patent Office: Days
• US Class Current: 717/162
• CPC Class Codes: G06F 11/3409 for performance assessment
• CPC Class Codes: G06F 11/3466 Performance evaluation by tracing or monitoring
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 12/1045 associated with a data cache
• CPC Class Codes: G06F 2201/865 Monitoring of software
• CPC Class Codes: G06F 2201/88 Monitoring involving counting
• CPC Class Codes: G06F 2201/885 Monitoring specific for caches

Abstract

A method (400) and system (106) is provided for run-time cache optimization. The method includes profiling (402) a performance of a program code during a run-time execution, logging (408) the performance for producing a cache log, and rearranging (410) a portion of program code in view of the cache log for producing a rearranged portion. The rearranged portion is supplied to a memory management unit (240) for managing at least one cache memory (110-140). The cache log can be collected during a real-time operation of a communication device and is fed back to a linking process (244) to maximize a cache locality compile-time. The method further includes loading a saved profile corresponding with a run-time operating mode, and reprogramming a new code image associated with the saved profile.

Claims

1. A system for run-time cache optimization, comprising

a cache logger, wherein the cache logger creates a profile of performance of a program code during a run-time execution thereby producing a cache log;

and

a memory management director, wherein the memory management director rearranges at least a portion of said program code in view of said profile and produces a rearranged portion,

wherein said memory management director provides at least said portion of the program code to a memory management unit that manages at least one cache memory in accordance with said cache log.

2. The system of claim 1, wherein said cache logger further comprises:

a counter, wherein said counter counts the number of times a function within said program code is called;

a timer, wherein said timer determines how often said function is called;

a trigger, wherein said trigger activates a response when a count from the counter exceeds a cache miss to cache hit ratio; and

a database table, wherein said database table holds calling functions and cache count misses,

wherein said response re-links said rearranged portion to produce a new image.

3. The system of claim 1, wherein said cache logger identifies cache misses during a real-time operation of a communication device in said cache log that is fed back to a linking process to maximize a cache locality compile-time.

4. The system of claim 2, wherein said memory management director minimizes an address distance of a called function within said program code.

5. The system of claim 2, wherein said rearranging is based on a calling frequency of at least one function contained within said program code.

6. The system of claim 1, wherein said memory management director uses said rearranged portion of program code to reprogram a new memory map in accordance with said cache log.

7. The system of claim 1, wherein said memory management replaces a short function of said program code by a macro.

8. The system of claim 1, wherein a cache pre-processing rule is applied to at least one function of said program code during a linking operation.

9. The system of claim 1, wherein said cache logger logs a cache miss in real-time based on a set of rules, triggers, counters, timers, weights, radio modes and registers.

10. The system of claim 1, further including a user interface for providing a cache configuration, wherein said program code is statically recompiled in view of a selected profile.

11. A method for run-time cache optimization, comprising the steps of:

profiling a performance of a program code during a run-time execution;

logging said performance for producing a cache log; and

rearranging a portion of program code in view of said cache log for producing a rearranged portion,

wherein said rearranged portion is supplied to a memory management unit for managing at least one cache memory.

12. The method of claim 11, wherein said cache log is collected during a real-time operation of a communication device and is fed back to a linking process to maximize a cache locality compile-time.

13. The method of claim 11, further comprising

loading a saved profile corresponding with a run-time operating mode;

and

reprogramming a new code image associated with said saved profile.

14. The method of claim 11, wherein the step of profiling further includes:

detecting a calling function tree; and

determining a calling frequency of a function in said function tree.

15. The method of claim 11, wherein the step of rearranging further includes one of:

minimizing a function distance; and

replacing a function with a macro.

16. The method of claim 11, wherein said cache log identifies cache misses and said rearranging optimizes a cache locality compile-time.

17. The method of claim 11, wherein said rearranging minimizes an address distance of a called function based on a calling frequency of said function within said program code.

18. The method of claim 11, further comprising

identifying at least one real-time operating mode within a radio;

saving at least one cache log associated with a performance of a program code executing in said real-time operating mode for producing at least one saved profile;

wherein a saved cache log and a program image is loaded into said radio when said radio enters a new operating mode.

19. A machine readable storage, having stored thereon a computer program having a plurality of code sections executable by a portable computing device for causing the portable computing device to perform the steps of:

profiling a performance of a program code during a run-time execution;

logging said performance for producing a cache log; and

rearranging a portion of program code in view of said cache log for producing a rearranged portion,

wherein said cache log is collected during a real-time operation of a communication device and is fed back to a linking process to maximize a cache locality compile time.

20. The machine readable storage of claim 19, further including the steps of:

minimizing the distance of a called function;

rearranging functions based on a calling frequency;

optimizing said functions to reduce a distance to other functions; and

replacing a short function by a macro,

wherein said cache log identifies cache misses with called functions causing said cache misses.