In multiprocessing system executing processing called NUMA prefetch, when a prefetch
instruction is issued to a prefetch unit, an address converter converts an address
specified by an operand of the instruction into a physical address. A prefetch
type determiner determines whether the instruction is an NUMA prefetch instruction
or a conventional perfect prefetch instruction. If the instruction is an NUMA prefetch
instruction, an address determiner determines whether the physical address is a
local address or a remote address. If the address is a local address, the processing
of the prefetch instruction is terminated. If the address is a remote address,
a cache tag checker checks a cache. When cache hit occurs, the processing is terminated.
When cache mishit occurs, a prefetch request is issued to a main storage controller.
As a result, data is prefetched from a remote main storage to a cache in a local
main storage.
