The present invention relates to storage system technology; and, in particular, the invention relates to a technique for achieving a high-performance storage system wherein a plurality of processors are incorporated in a controller. 
Conventionally, there is a multi-processor construction (for example, see Laid-open Japanese Patent Application No.  2003-006174) employing SMP (symmetric multi-processing) as a means of improving the performance of a computer system.  In Laid-open Japanese Patent Application No.  2003-006174, parallel processing is made possible by arranging for a plurality of processors to share computer resources, such as memory.