Method and apparatus to trigger synchronization and validation actions upon memory access

• US 8,327,084 B2
• Filed: 08/30/2007
• Issued: 12/04/2012
• Est. Priority Date: 08/30/2007
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: von Praun, Christoph, Ceze, Luis
• Primary Examiner(s): Rones, Charles
• Assistant Examiner(s): SADLER, NATHAN
• Application Number:
  US11/847,917
• Publication Number:
  US 20090063783A1
• Time in Patent Office: 1,923 Days
• Field of Search: 711/150
• US Class Current: 711/150
• CPC Class Codes: G06F 12/084 with a shared cache
• CPC Class Codes: G06F 12/0842 for multiprocessing or multitasking
• CPC Class Codes: G06F 12/1027 using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB]
• CPC Class Codes: G06F 12/1036 for multiple virtual address spaces, e.g. segmentation G06F12/1045 takes precedence
• CPC Class Codes: G06F 12/1466 Key-lock mechanism

Abstract

A system and method to trigger synchronization and validation actions at memory access, in one aspect, identifies a storage class associated with a region of shared memory being accessed by a thread, determines whether the thread holds the storage class and acquires the storage class if the thread does not hold the storage class, identifies a programmable action associated with the storage class and the thread, and triggers the programmable action. One or more storage classes are respectively associated with one or more regions of shared memory. An array of storage classes associated with a thread holds one or more storage classes acquired by the thread. A configurable action table associated with a thread indicates one or more programmable actions associated with a storage class.

Claims

1. A method to trigger synchronization and validation actions at memory access, comprising:

identifying a storage class associated with a region of shared memory being accessed by a thread, in a memory system having the shared memory in which one or more regions at a predetermined granularity are assigned storage classes, the storage class represented as a fixed number of bits that identify the storage class, and in response to determining that no storage class is identified with the region of shared memory being accessed by the thread, issuing memory access in normal manner, and in response to identifying the storage class, performing;

determining whether the thread holds the storage class and acquiring the storage class automatically if the thread does not hold the storage class, the acquiring including holding the storage class in an array of storage classes in the thread'"'"'s own memory context such that the array of storage classes is private to the thread and wherein the storage class is not exclusive to a thread such that the same storage class can be acquired by multiple threads;

identifying a programmable action associated with the storage class held by the thread, the identifying including looking up an action table storing one or more storage classes and associated programmable actions in response to identifying the storage class associated with a region of shared memory being accessed by a thread, the action table being a process specific data structure that is configurable, including encoding of an action related to the storage class, a context that specifies whether the action should be taken upon the storage class held or not held, an operation that specifies if the action should be invoked at read, write, or read and write, and an action specification, entries in the action table enabled to be registered and removed through a set of predetermined functions; and

triggering the programmable action based on the storage class assigned to the accessed shared memory location, the thread'"'"'s array of storage classes, and type of memory access.

2. The method of claim 1, wherein the programmable action includes one or more synchronization actions.

3. The method of claim 1, wherein the programmable action includes one or more validation actions.

4. The method of claim 1, further including:

assigning one or more storage classes respectively to one or more regions of shared memory.

5. The method of claim 4, further including:

using virtual memory mapping structure for assigning said one or more storage classes respectively to one or more regions of shared memory, wherein the virtual memory mapping structure identifies whether the region of shared memory has an assigned storage class, and wherein said one or more regions of shared memory are respectively assigned said one or more storage classes by performing a set operation provided for programming the virtual memory mapping structure, wherein the set operation sets the fixed number of bits in an information field of the virtual memory mapping structure, wherein the virtual memory mapping structure is a virtual memory address to physical memory address translation table.

6. The method of claim 5, wherein the step of using includes:

extending a page table entry to include a storage field class.

7. The method of claim 4, wherein said one or more storage classes is respectively associated with said one or more regions of shared memory at a selected level of granularity.

8. The method of claim 4, further including:

establishing the array of storage classes, the array holding one or more storage classes that the thread has acquired.

9. The method of claim 4, further including:

establishing a configurable action table and associating the configurable action table with the thread, the configurable action table specifying one or more programmable actions associated with a storage class.

10. A system for triggering synchronization and validation actions at memory access, comprising:

a processing unit;

a memory system structure that maps one or more storage classes to respective one or more regions of shared memory, in a memory system having the shared memory in which one or more regions at a predetermined granularity are assigned storage classes, the storage class represented as a fixed number of bits that identify the storage class;

one or more arrays of storage classes respectively associated with one or more threads executing in the processing unit, one array for each thread, said one or more arrays operable to hold one or more storage classes acquired by said respective one or more threads and wherein the storage class is not exclusive to a thread such that the same storage class can be acquired by multiple threads; and

one or more configurable action tables respectively associated with said one or more threads executing in the processing unit, said one or more configurable action tables specifying one or more configurable actions associated with one or more storage classes, the configurable action table being a process specific data structure that is configurable, including encoding of an action related to the storage class, a context that specifies whether the action should be taken upon the storage class held or not held, an operation that specifies if the action should be invoked at read, write, or read and write, and an action specification, entries in the action table enabled to be registered and removed through a set of predetermined functions,

wherein a thread executing in the processing unit and attempting access to said one or more regions of shared memory which have storage classes assigned and which storage classes the thread holds, causes one or more configurable actions to be triggered based on content of an array of storage classes and a configurable action table associated with said thread.

11. The system of claim 10 wherein the memory system structure maps one or more storage classes to respective one or more regions of shared memory at a selected level of granularity.

12. The system of claim 10, wherein the memory system structure includes a virtual memory system and a page table entry in the virtual memory system includes a field for specifying said one or more storage classes corresponding to memory address in the page table entry.

13. The system of claim 10, wherein said one or more configurable actions include synchronization actions.

14. The system of claim 10, wherein said one or more configurable actions include validation actions.

15. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a method to trigger synchronization and validation actions at memory access, comprising:

identifying a storage class associated with a region of shared memory being accessed by a thread, in a memory system having the shared memory in which one or more regions at a predetermined granularity are assigned storage classes, the storage class represented as a fixed number of bits that identify the storage class, and in response to determining that no storage class is identified with the region of shared memory being accessed by the thread, issuing memory access in normal manner, and in response to identifying the storage class, performing;

determining whether the thread holds the storage class and acquiring the storage class automatically if the thread does not hold the storage class, the acquiring including holding the storage class in an array of storage classes in the thread'"'"'s own memory context such that the array of storage classes is private to the thread and wherein the storage class is not exclusive to a thread such that the same storage class can be acquired by multiple threads;

identifying a programmable action associated with the storage class, the identifying including looking up an action table register storing one or more storage classes and associated programmable actions in response to identifying the storage class associated with a region of shared memory being accessed by a thread, the action table register being a process specific data structure that is configurable, including encoding of an action related to the storage class, a context that specifies whether the action should be taken upon the storage class held or not held, an operation that specifies if the action should be invoked at read, write, or read and write, and an action specification, entries in the action table register enabled to be registered and removed through a set of predetermined functions; and

triggering the programmable action based on the storage class assigned to the accessed shared memory location, the thread'"'"'s array of storage classes, and type of memory access.

16. The program storage device of claim 15, wherein the programmable action includes one or more synchronization actions.

17. The program storage device of claim 15, wherein the programmable action includes one or more validation actions.

18. The program storage device of claim 15, further including:

associating one or more storage classes respectively with one or more regions of shared memory.

19. The program storage device of claim 18, further including:

using virtual memory mapping structure for associating said one or more storage classes respectively with one or more regions of shared memory.

20. The program storage device of claim 18, wherein said one or more storage classes is respectively associated with said one or more regions of shared memory at a selected level of granularity.