Removing CPU Affinity for I/O Via Channel Set Switching
Original Publication Date: 1981-Oct-01
Included in the Prior Art Database: 2005-Feb-12
In IBM System/370 architecture, an affinity exists between Central Processing Units (CPUs) and control paths to input/output (I/O) devices so that some devices may be accessed from only one CPU in a multi-processor configuration. Thus, requests for I/O operations which are received from programs executing on a processor without a path to the requested device must be passed to the other processor; this causes additional overhead, and delay in initiating the operation.