Data-maintenance method of distributed shared memory system
AssigneeVIA Technologies, Inc.
InventorsWei-Long Chen, Wayne Tseng, Jiin Lai
Life of this patent
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Abstract
A distributed shared memory (DSM) system includes at least a first and a second nodes. The first node includes an external cache for storing a data from a local memory of the second node and at least two processors optionally accessing the data from the external cache. Whether the data has been modified into a modified data by a first certain one of the at least two processors is first determined. If positive, whether a second certain one of the at least two processors is allowed to share the modified data is further determined. If the second certain processor is allowed to share the modified data, it may directly request the modified data from the first certain processor via a bus inside the first node.
Claims18
A data maintenance method of a distributed shared memory (DSM) system, said DSM system including at least a first and a second nodes, said first node including an external cache for storing a data from a local memory of said second node and at least two processors optionally accessing said data from said external cache, and said data maintenance method comprising steps of:
- discriminating whether said data has been modified into a modified data by a first certain one of said at least two processors;
- discriminating whether a second certain one of said at least two processors is allowed to share said modified data if said data has been modified by said certain processor;
- and
- directly requesting said modified data by said second certain processor via a bus inside said first node if said second certain processor is allowed to share said modified data.
A data maintenance method of a distributed shared memory (DSM) system, said DSM system including at least a first and a second nodes, said first node including an external cache for storing a data from a local memory of said second node and at least two processors optionally accessing said data from said external cache, and said data maintenance method comprising steps of:
- discriminating whether said data has been modified by a first certain one of said at least two processors on the condition that a cache line of said external cache, where said data is stored, is in a CLEAN state;
- changing the state of said cache line from said CLEAN state to either of DIRTY-SHARED and DIRTY-ONLY state if said data has been modified into a modified data;
- and
- allowing a second certain one of said at least two processors to directly request said modified data via a bus inside said first node when said cache line is in said DIRTY-SHARED state.
Dependencies are inferred from the claim text.