Methods and apparatus for supporting persistent memory

Patent metadata

Field	Value
Publication number	US-9244839-B2
Application number	US-201314125741-A
Country	US
Kind code	B2
Filing date	Jul 26, 2013
Priority date	Jul 26, 2013
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

A processing device features a processing unit, a memory management system, and persistent memory in a persistent memory domain. The processing device provides an enhanced write-back (WB-E) memory space for an application running on the processing unit. The memory management system maps the WB-E memory space to the persistent memory. The application creates WB-E data by executing an instruction to store data to an address in the WB-E memory space. The WB-E data is automatically stored in a cache associated with the processing unit in response to creation of the WB-E data by the application. In response to execution of a commit instruction by the application after the application has created WB-E data for multiple memory addresses, the memory management system automatically ensures that all of the WB-E data for the application has been saved to the persistent memory domain. Other embodiments are described and claimed.

First claim

What is claimed is:

1. A data processing system with features to support persistent memory, the data processing system comprising:
a processing element;
at least one machine accessible medium responsive to the processing element, wherein the at least one machine accessible medium comprises persistent memory to operate within a persistent memory domain; and
a memory management system to facilitate communications between the processing element and the persistent memory, wherein the memory management system is configured to enable the data processing system to perform operations comprising:
providing an enhanced write-back (WB-E) memory space for an application running on the processing element;
mapping the WB-E memory space to the persistent memory;
in response to creation of WB-E data by the application, automatically storing the WB-E data in a cache associated with the processing element, wherein the application creates WB-E data by executing an instruction to store data to an address in the WB-E memory space; and
in response to execution of a commit instruction by the application after the application has created WB-E data for multiple memory addresses, automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain.

2. A data processing system according to claim 1 , wherein:
the data processing system comprises a main memory controller responsive to the processing element; and
the operations further comprise, in response to a pre-commit serializing instruction, if any of the WB-E data for the application has not already been written from the cache to a main memory controller in the data processing system, writing said WB-E data from the cache to the main memory controller.

3. A data processing system according to claim 2 , wherein:
the operation of writing the WB-E data from the cache to the main memory controller is performed before the operation of automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain; and
the operation automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain comprises writing all WB-E data for the application in the main memory controller from the main memory controller to the persistent memory domain.

4. A data processing system according to claim 3 , wherein the operations further comprise:
in response to execution of a post-commit serializing instruction by the application, returning control to the application only after all of the WB-E data for the application has been saved to the persistent memory domain.

5. A data processing system according to claim 1 , wherein:
the memory management system comprises a main memory controller responsive to the processing element; and
the operations further comprise:
automatically determining whether resources needed to write data from the cache to the main memory controller are available;
automatically determining whether the cache contains any WB-E data; and
in response to determinations that (a) resources needed to write data from the cache to the main memory controller are available and (b) the cache contains WB-E data, automatically writing at least some of the WB-E data from the cache to the main memory controller.

6. A data processing system according to claim 5 , wherein the operations further comprise:
automatically determining whether resources needed to write data from the main memory controller to the persistent memory domain are available;
automatically determining whether the main memory controller contains any WB-E data; and
in response to determinations that (a) resources needed to write data from the main memory controller to the persistent memory domain are available and (b) the persistent memory domain contains WB-E data, automatically writing at least some of the WB-E data from the main memory controller to the persistent memory domain.

7. A data processing system according to claim 1 , wherein:
the memory management system comprises a main memory controller responsive to the processing element; and
the operations further comprise:
automatically determining whether resources needed to write data from the main memory controller to the persistent memory domain are available;
automatically determining whether the main memory controller contains any WB-E data; and
in response to determinations that (a) resources needed to write data from the main memory controller to the persistent memory domain are available and (b) the persistent memory domain contains WB-E data, automatically writing at least some of the WB-E data from the main memory controller to the persistent memory domain.

8. A method for supporting persistent memory, the method comprising:
providing an enhanced write-back (WB-E) memory space for an application running on a processing unit of a processing device, wherein the processing device comprises a memory management system and persistent memory in a persistent memory domain, and wherein the memory management system maps the WB-E memory space to the persistent memory;
automatically storing WB-E data in a cache associated with the processing unit in response to creation of the WB-E data by the application, wherein the application creates the WB-E data by executing an instruction to store data to an address in the WB-E memory space; and
in response to execution of a commit instruction by the application after the application has created WB-E data for multiple memory addresses, automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain, wherein the operation of automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain is performed by the memory management system.

9. A method according to claim 8 , further comprising:
in response to a pre-commit serializing instruction, if any of the WB-E data for the application has not already been written from the cache to a main memory controller in the processing device, writing said WB-E data from the cache to the main memory controller.

10. A method according to claim 9 , wherein:
the operation of writing the WB-E data from the cache to the main memory controller is performed before the operation of automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain; and
the operation automatically ensuring that all of the WB-E data for the application has been saved to the persistent memory domain comprises writing all WB-E data for the application in the main memory controller from the main memory controller to the persistent memory domain.

11. A method according to claim 8 , further comprising:
in response to execution of a post-commit serializing instruction by the application, returning control to the application only after all of the WB-E data for the application has been saved to the persistent memory domain.

12. A method according to claim 8 , further comprising:
automatically determining whether resources needed to write data from the cache to a main memory controller are available;
automatically determining whether the cache contains any WB-E data; and
in response to determinations that (a) resources needed to write data from the cache to the main memory controller are available and (b) the cache contains WB-E data, automatically writing at least some of the WB-E data from the cache to the main memory controller.

13. A method according to claim 12 , further comprising:
automatically determining whether resources needed to write data from t

Assignees

• Intel Corp

Inventors

• Sakthivelu Sridharan
• Bahnsen Robert Bruce
• Saylor Gerrit

Classifications

• G06F12/0804 Primary

  with main memory updating (G06F12/0806 takes precedence) · CPC title

• G06F2212/1044

  Space efficiency improvement · CPC title

• G06F12/126

  with special data handling, e.g. priority of data or instructions, handling errors or pinning · CPC title