Patent ID: 6748460
Filing Date: 2004-06-08
Classification: G06F

Abstract:
An apparatus comprising:a processor handling an I/O request in an I/O operation; main storage controlled by the processor for storing data; one or more I/O devices for sending data to or receiving data from said main storage; a hierarchy of vectors registering I/O requests by said devices to send or receive data from said main storage, said hierarchy of vectors having one or more lower levels and a highest level, each device setting a vector in the lowest level of said hierarchy for registering an I/O request, the setting of a vector in the lowest level being reflected up the hierarchy to the highest level of said hierarchy thereby registering I/O requests on any lower level of said hierarchy in the highest level; and a dispatcher polling said hierarchy in high to low order, said dispatcher passing initiative to the processor to handle I/O requests registered in said hierarchy responsive to registering of an I/O request on said lowest level as reflected to the highest level of said hierarchy.