METHOD AND DEVICE FOR SELECTIVELY STOPPING DMA OPERATION, AND DATA PROCESSING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a mechanism for temporarily stopping DMA operation selected in a physical I/O adapter in order to allow data to migrate between physical pages which receive accesses by the physical I/O adapter. SOLUTION: When receiving a request for DMA to the physical page in a system memory from the I/O adapter, migration in progress display (MIP) bit in a transformation control entry (TCE) pointing to the physical page is examined. The MIP bit expresses whether or not migration to other locations in the system memory with respect to the physical page referred to in the TCE is in process. When the MIP bit expresses that the migration of the physical page is in progress, DMA from the I/O adapter is temporarily stopped, whereas other DMA operation to other physical pages in the system memory from other I/O adapters are permitted to continue. COPYRIGHT: (C)2008,JPO&INPIT