发明名称 |
Method, apparatus, and computer program product for a cache coherency protocol state that predicts locations of shared memory blocks |
摘要 |
A method, apparatus, and computer program product are disclosed for reducing the number of unnecessarily broadcast local requests to reduce the latency to access data from remote nodes in an SMP computer system. A shared invalid cache coherency protocol state is declined that predicts whether a memory read request to read data in a shared cache line can be satisfied within a local node. When a cache line is in the shared invalid state, a valid copy of the data is predicted to be located in the local node. When a cache line is in the invalid state and not in the shared invalid state, a valid copy of the data is predicted to be located in one of the remote nodes. Memory read requests to read data in a cache line that is not currently in tile shared invalid state are broadcast first to remote nodes. Memory read requests to read data in a cache line that is currently in the shared invalid state are broadcast first to a local node, and in response to being unable to satisfy the memory read requests within the local node, the memory read requests are broadcast to the remote nodes.
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申请公布号 |
US7395376(B2) |
申请公布日期 |
2008.07.01 |
申请号 |
US20050184315 |
申请日期 |
2005.07.19 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
CANTIN JASON FREDERICK;KUNKEL STEVEN R. |
分类号 |
G06F12/00;G06F13/00;G06F13/28 |
主分类号 |
G06F12/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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