Importance

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Abstract

A method and apparatus are provided for enhanced scatter mode allowing user data to be page aligned in a memory. An adapter is coupled between a data communications network and the memory. A data packet including protocol header bytes is received from a data communications network by the adapter. A variable amount of data is specified for a first scatter page that contains the protocol header bytes. Subsequent sequential pages from the received data packet are transferred, for example, by direct memory access (DMA) operations, to real page addresses in the memory with the sequential pages transferred being page aligned in the memory. A page address is written to a DMA list stored in an adapter memory for the sequential pages transferred. A count value is incremented in a packet header of a number of pages transferred for each sequential page transferred. Responsive to transferring a last page from the received data packet, the first scatter page containing the packet header, the DMA list and the protocol header bytes is transferred to a separate address space in the memory. A small packet or single page size is specified for the adapter. When the total data size of a received packet is less than this small packet size, then the packet is not scattered. A single page mode is performed to transfer the small packet to the memory.

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First Claim