Operating System Integration

The Problem

Networked File Systems touch both virtual memory pages to cache file data and networking structures, mbufs, to communicate between client and server. This can result in unnecessary data copies.

The Solution

Cluster mbufs are used to allow clients (senders of packets) that are writing data to avoid an extra data copy. The server (receiver of packets) cannot benefit from this optimization without major redesign of network device drivers to parse data packets.

Results

Averages of 25 writes various sized files/ write system call. The prototype hardware is used, but no data is written to disk. "ATOMIC File Server" is SunOS NFS with both these improvements and the context switch improvements. "NFS" is SunOS NFS modified to not write to disk. Standard deviation error bars are plotted.

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Last modified July 9, 1997