Efficient Memory Allocation Across Multiple Accessing Systems

• US 20100161908A1
• Filed: 12/18/2008
• Published: 06/24/2010
• Est. Priority Date: 12/18/2008
• Status: Abandoned Application

• Current Assignee: LSI Corporation (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Ober, Robert E., Nation, George
• Application Number:
  US12/338,154
• Publication Number:
  US 20100161908A1
• Time in Patent Office: Days
• US Class Current: 711/147
• CPC Class Codes: G06F 12/0284 Multiple user address space allocation, e.g. using different base addresses interprocessor communication G06F15/163
• CPC Class Codes: G06F 2212/205 Hybrid memory, e.g. using both volatile and non-volatile memory

Abstract

Various embodiments of the present invention provide systems and methods for reducing memory usage across multiple virtual machines. For example, various embodiments of the present invention provide methods for reducing resource duplication across multiple virtual machines. Such methods include allocating a shared memory resource between a first virtual machine and a second virtual machine. A data set common to both the first virtual machine and the second virtual machine is identified. A first set of configuration information directing access to the data set by the first virtual machine to a first physical memory space is provided, and a second set of configuration information directing access to the data set by the second virtual machine to a second physical memory space is provided. The first physical memory space at least partially overlaps the second physical memory space.

Claims

1. A method for reducing resource duplication across multiple virtual machines, the method comprising:

allocating a shared memory resource between a first virtual machine and a second virtual machine;

identifying a data set common between the first virtual machine and the second virtual machine;

providing a first set of configuration information directing access to the data set by the first virtual machine to a first physical memory space; and

providing a second set of configuration information directing access to the data set by the second virtual machine to a second physical memory space, wherein the first physical memory space at least partially overlaps the second physical memory space.

2. The method of claim 1, wherein the first physical memory space is coextensive with the second physical memory space.

3. The method of claim 1, wherein the first set of configuration information identifies at least a portion of the first physical memory space that overlaps at least a portion of the second physical memory space as read only.

4. The method of claim 1, wherein determination that the second virtual machine uses the data set occurs prior to allocating the shared memory appliance to the second virtual machine.

5. The method of claim 1, wherein the second set of configuration information initially directs access to the data set by the second virtual machine to a third physical memory space, wherein the third physical memory space at least partially overlaps the second physical memory space, and wherein the method further comprises:

receiving a request to de-duplicate the data set;

re-directing accesses by the second virtual machine to the second physical memory space; and

de-allocating at least a portion of the third physical memory space.

6. The method of claim 1, wherein the second set of configuration information initially directs access to the data set by the second virtual machine to a third physical memory space, wherein the third physical memory space is exclusive of the second physical memory space, and wherein the method further comprises:

receiving a request to de-duplicate the data set;

re-directing accesses by the second virtual machine to the second physical memory space; and

de-allocating the third physical memory space.

7. The method of claim 1, wherein the method further comprises:

additionally allocating a portion of the shared memory resource to a third virtual machine, wherein the third virtual machine utilizes the data set; and

providing a third set of configuration information directing access to the data set by the third virtual machine to a third physical memory space, wherein the first physical memory space at least partially overlaps the third physical memory space.

8. The method of claim 5, wherein the first physical memory space is coextensive with the third physical memory space.

9. The method of claim 1, wherein the method further comprises:

prior to allocating a portion of the shared memory resource to a third virtual machine, identifying use of the data set by the third virtual machine; and

allocating the shared memory resource to the third virtual machine, wherein a third set of configuration information is written to direct access of the data set by the third virtual machine to a third physical memory space, wherein the first physical memory space at least partially overlaps the third physical memory space.

10. The method of claim 1, wherein the shared memory resource is a memory appliance, and wherein the memory appliance includes:

a memory bank accessible to the first virtual machine and the second virtual machine via a network interface.

11. A shared memory system, wherein the system comprises:

a memory appliance including a memory space accessible via an interface device;

a first virtual machine, wherein the first virtual machine is communicably coupled to the memory appliance with the interface device, wherein the first virtual machine is allocated a first portion of the memory space, and wherein the first virtual machine utilizes an data set;

a second virtual machine, wherein the second virtual machine is communicably coupled to the memory appliance with the interface device, wherein the second virtual machine is allocated a second portion of the memory space, and wherein the second virtual machine utilizes the data set; and

wherein the memory appliance is operable to direct an access to the data set by the first virtual machine and the second virtual machine to a common physical address in the memory space.

12. The system of claim 11, wherein at least a portion of the allocation is initially allocated to a first memory region exclusive to the first virtual machine and to a second memory region exclusive to the second virtual machine.

13. The system of claim 12, wherein directing the access to the data set to the common physical address is done after receiving a request to de-duplicate the data set in the memory space.

14. The system of claim 11, wherein the first virtual machine and the second virtual machine are implemented using a single processor.

15. The system of claim 11, wherein the first virtual machine is implemented using a first processor and wherein the second virtual machine is implemented using a second processor.

16. A method for distributing memory resources in a processing environment, the method comprising:

providing a memory appliance, wherein the memory appliance includes a memory space and an interface device;

communicably coupling a first virtual machine to the memory appliance via the memory appliance, wherein the first virtual machine uses an data set;

communicably coupling a first virtual machine to the memory appliance via the memory appliance, wherein the second virtual machine uses the data set;

allocating a first portion of the memory space to the first virtual machine;

allocating a second portion of the memory space to the second virtual machine; and

allocating a third portion of the memory space including at least a portion of the data set to both the first virtual machine and the second virtual machine.

17. The method of claim 16, wherein the third portion of the memory space is originally allocated only to the first virtual machine, and wherein a fourth portion of the memory space including at least the portion of the data set is originally allocated to the second virtual machine, and wherein the system is operable to modify de-allocate the fourth portion and to allocate the third portion to the second virtual machine.