Directory storage control for commonly used patterns

• US 10,452,266 B2
• Filed: 12/27/2016
• Issued: 10/22/2019
• Est. Priority Date: 12/30/2015
• Status: Active Grant

• Current Assignee: Arteris Incorporated
• Original Assignee: Arteris Incorporated
• Inventors: Gaikwad, Parimal
• Primary Examiner(s): Rones, Charles
• Assistant Examiner(s): Li, Hewy H
• Application Number:
  US15/390,749
• Publication Number:
  US 20170192680A1
• Time in Patent Office: 1,029 Days
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 12/0817 using directory methods
• CPC Class Codes: G06F 12/0893 Caches characterised by their organisation or structure
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/621 Coherency control relating to peripheral accessing, e.g. from DMA or I/O device
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0673 Single storage device

Abstract

A system and method are disclosed with the ability to track usage of information and determine commonly used patterns to be stored and updated in a directory. The information includes counter values that represent the frequency of occurrence of a pattern that is committed to the directory. Thus, allows the system to control and reduce the size allocated to storing information in the directory because the size is reduced by limiting address bits. This, in turn, creates additional benefits in speed and power because it allows subsystems to avoid transmitting, storing, and operating upon excessive address information.

Claims

1. A method for reducing directory size within a system, the method comprising:

setting, by a defragment control logic unit, a default encoding for a directory having a plurality of patterns, wherein each pattern represents sharing of information among agents in the system and each pattern has a counter value;

tracking, by a statistical logic unit, through updating the counter value for each pattern as each pattern is committed to the directory;

generating an update encoding for the directory that includes a group of patterns that have a highest counter value;

updating the directory from the default encoding to the updated encoding; and

determining, using a control bit, if the updated encoding is a new encoding or an old encoding.

2. The method of claim 1, wherein the step of tracking includes the step of incrementing the counter for each pattern.

3. The method of claim 2, wherein the step of generating includes selecting the group of patterns.

4. The method of claim 1, further including the steps of:

using a control bit entry for each address line encoded in the directory, the control bit entry indicating if the pattern is at least one of old encoding or new encoding; and

maintain a first table and a second table, the first table is an old encoding and the second table is a new encoding,

wherein the control bit entry determines if encoding from the first table or the second table is used by the system.

5. The method of claim 1, wherein the step of updating includes defragmenting, by the defragment control logic unit, the directory based on the updated encoding.