System, method and computer program product for page sharing between fault-isolated cells in a distributed shared memory system
First Claim
1. A method for sharing memory between a first cell and a second cell of a distributed shared memory system, wherein the first cell and the second cell are separated by a fault-isolating fire-wall, comprising the steps of:
- (1) receiving a request in the first cell to access a page of memory that is located in the first cell, the request having been sent by the second cell;
(2) determining in the first cell whether the second cell is permitted to access the page of memory;
(3)(a) opening a portion of the fault-isolating fire-wall between the first cell and the second cell to permit the second cell to access the page of memory, if the second cell is permitted to access the page of memory;
(3)(b) generating a record of the page of memory exported from the first cell to the second cell; and
(4) closing the opened portion of the fault-isolating fire-wall.
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Accused Products
Abstract
A system, method and computer program product for sharing memory between fault-isolated cells of a computer system. A page of memory is exported from an exporting cell to an importing cell by selectively opening a hole in a fire-wall that otherwise fault-isolates the exporting cell and the importing cell. The fire-wall opening permits the importing cell to access a specific page of memory in the exporting cell. Access to other memory cells is still prevented by the fire-wall. When a page of memory is exported, a record of the export is generated in the exporting cell. Export records are used to determine whether a requesting cell is permitted to access a requested page of memory and to terminate memory exports in a controlled fashion. When a page of memory is imported, an import record and a proxy page frame data structure are generated in the importing cell. Import records are used to access pages of memory in other cells and to terminate imports in a controlled fashion. Proxy page frame data records are used to maintain fault isolation between cells and to ensure that kernel data is never shared between cells.
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Citations
43 Claims
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1. A method for sharing memory between a first cell and a second cell of a distributed shared memory system, wherein the first cell and the second cell are separated by a fault-isolating fire-wall, comprising the steps of:
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(1) receiving a request in the first cell to access a page of memory that is located in the first cell, the request having been sent by the second cell; (2) determining in the first cell whether the second cell is permitted to access the page of memory; (3)(a) opening a portion of the fault-isolating fire-wall between the first cell and the second cell to permit the second cell to access the page of memory, if the second cell is permitted to access the page of memory; (3)(b) generating a record of the page of memory exported from the first cell to the second cell; and (4) closing the opened portion of the fault-isolating fire-wall. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for sharing memory between a first cell and a second cell of a distributed shared-memory system, wherein the first cell and the second cell are separated by a fault-isolating fire-wall, comprising the steps of:
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(1) sending a request from the first cell to the second cell to access a page of memory that is located in the second cell; (2) receiving the request in the second cell; (3) determining in the second cell whether the first cell is permitted to access the page of memory; (4) opening a portion of the fault-isolating fire-wall between the first cell and the second cell to permit the first cell to access the page of memory, if the first cell is permitted to access the page of memory; (5) importing the page of memory from the second cell; and (6) closing the opened portion of the fault-isolating fire-wall. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A system for sharing memory between a first and a second cell of a fault-isolated, distributed shared memory system, comprising:
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a module that exports a first page of memory from the first cell to the second cell, wherein said module that exports comprises a module that opens a portion of a fire-wall that fault-isolates the first cell from the second cell; and a module that imports a second page of memory to the first cell from the second cell. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34)
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35. A computer program product comprising a computer useable medium having computer program logic stored therein, said computer program logic for enabling a first cell and a second cell of a fault-isolated, distributed shared memory computer system to share memory, wherein said computer program logic comprises:
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a procedure that enables the first cell of the computer to export a first page of memory from the first cell to the second cell, wherein said procedure that enables the first cell of the computer to export a first page of memory comprises a procedure that enables the first cell of the computer to open a portion of a fire-wall that fault-isolates the first cell from the second cell; and a procedure that enables the first cell of the computer to import a second page of memory to the first cell from the second cell. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42)
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43. A system for sharing memory between a first and a second cell of a fault-isolated, distributed shared memory system, comprising:
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means for exporting a first page of memory from the first cell to the second cell, wherein said means for exporting comprises means for opening a portion of a fire-wall that fault-isolates the first cell from the second cell; and means for importing a second page of memory to the first cell from the second cell.
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Specification