| 摘要 |
An operating system monitors a performance metric of a direct memory access (DMA) engine on an I/O adapter to update a translation table used during DMA operations. The translation table is used during a DMA operation to map a virtual address provided by the I/O adapter to a physical address of a data page in the memory modules. If the DMA engine is being underutilized, the operating system updates the translation table such that a virtual address maps to physical address corresponding to a memory location in a more energy efficient memory module. However, if the DMA engine is over-utilized, the operating system may update the translation table such that the data used in the DMA engine is stored in memory modules that provide quicker access times—e.g., the operating system may map virtual addresses to physical addresses in DRAM rather than phase change memory. |
