METHOD AND APPARATUS FOR MEMORY MANAGEMENT

• US 20150067264A1
• Filed: 08/28/2013
• Published: 03/05/2015
• Est. Priority Date: 08/28/2013
• Status: Active Grant

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Eckert, Yasuko, Manne, Srilatha, Loh, Gabriel, Jafri, Syed Ali
• Granted Patent: US 10,133,678 B2
• Time in Patent Office: Days
• US Class Current: 711/133
• CPC Class Codes: G06F 12/126 with special data handling, e.g. priority of data or instructions, handling errors or pinning
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In some embodiments, a method of managing cache memory includes identifying a group of cache lines in a cache memory, based on a correlation between the cache lines. The method also includes tracking evictions of cache lines in the group from the cache memory and, in response to a determination that a criterion regarding eviction of cache lines in the group from the cache memory is satisfied, selecting one or more (e.g., all) remaining cache lines in the group for eviction.

Claims

1. A method of managing cache memory, comprising:

identifying a group of cache lines in a cache memory, based on a correlation between the cache lines;

tracking evictions of cache lines in the group from the cache memory; and

responsive to a criterion regarding eviction of caches lines in the group from the cache memory being satisfied, selecting one or more remaining cache lines in the group for eviction.

2. The method of claim 1, further comprising determining whether the criterion regarding eviction of caches lines in the group from the cache memory is satisfied.

3. The method of claim 1, wherein selecting one or more remaining cache lines in the group for eviction comprises selecting all remaining cache lines in the group for eviction.

4. The method of claim 1, wherein the identifying comprises assigning cache lines installed in the cache memory during a specified time interval to the group.

5. The method of claim 1, wherein the identifying comprises assigning cache lines associated with a common prefetch event to the group.

6. The method of claim 5, wherein the assigning comprises grouping together cache lines in a common prefetch stream.

7. The method of claim 5, wherein the assigning comprises grouping together cache lines associated with a common prefetch table entry.

8. The method of claim 1, wherein the correlation between the cache lines is based on spatial locality between the cache lines in memory.

9. The method of claim 8, wherein the identifying comprises determining that the cache lines are from a common page in memory.

10. The method of claim 1, wherein the criterion comprises a threshold for a number of cache lines in the group that are evicted from the cache memory during a specified time interval.

11. The method of claim 10, further comprising:

incrementing a counter in response to eviction of cache lines in the group from the cache memory; and

in response to a request directed to a cache line in the group, setting the threshold to be greater than a value of the counter.

12. The method of claim 11, further comprising:

in a first-in-first-out (FIFO) buffer, buffering addresses of cache lines in the group that are evicted from the cache memory; and

in response to a determination that all addresses of evicted cache lines in the group have been de-queued from the FIFO buffer, setting the threshold to be less than the value of the counter.

13. The method of claim 1, wherein the criterion comprises a first threshold for an eviction correlation value for the group.

14. The method of claim 13, further comprising:

incrementing the eviction correlation value in response to a determination that a rate of cache line eviction from the group is greater than, or greater than or equal to, a second threshold; and

decrementing the eviction correlation value in response to a determination that a rate of cache line eviction from the group is less than, or less than or equal to, a third threshold.

15. The method of claim 1, wherein selecting one or more remaining cache lines in the group for eviction comprises setting modified remaining cache lines in the group as being least recently used within their respective sets.

16. The method of claim 1, further comprising invalidating unmodified remaining cache lines in the group in response to determining that the criterion is satisfied.

17. An apparatus , comprising:

a cache controller, to be coupled to a cache data array, comprising;

group identification logic to identify a group of cache lines in the cache data array, based on a correlation between the cache lines; and

eviction logic, responsive to a determination that a criterion regarding eviction of cache lines in the group from the cache data array is satisfied, to select one or more remaining cache lines in the group for eviction from the cache data array.

18. The apparatus of claim 17, wherein the group identification logic is to assign cache lines installed in the cache data array during a specified time interval to the group.

19. The apparatus of claim 17, wherein:

the cache controller further comprises a prefetcher to predictively fetch cache lines into the cache data array;

the prefetcher comprises the group identification logic; and

the group identification logic is to assign cache lines associated with a common prefetch event in the prefetcher to the group.

20. The apparatus of claim 17, wherein the correlation between the cache lines is based on the cache lines having matching bits in a portion of address bits associated with the cache lines.

21. The apparatus of claim 17, further comprising a processor core.

22. The apparatus of claim 21, wherein the processor core comprises the eviction logic.

23. An apparatus, comprising:

means for identifying a group of cache lines in a cache memory, based on a correlation between the cache lines;

means for tracking evictions of cache lines in the group from the cache memory;

means for determining whether a criterion regarding eviction of cache lines in the group from the cache memory is satisfied; and

means for selecting one or more remaining cache lines in the group for eviction, in response to determining that the criterion is satisfied.