Cache Preloads

Waiting on the cache to load values from memory is a big performance loss. Modern processors rely on the fact that the pipeline will be kept full as much as possible but mishandling the cache can easily prevent this. One easy way to overcome this problem is to provide hints to the hardware about access patterns. On the PowerPC and other architectures there are sets of instructions to do preloads of data cache entries before the actual access is done. This is a simple way, without large changes, to improve cache behavior and reduce stalls. We feel that we can make significant gains with intelligent use of cache preloads in context switching and interrupt entry code.