ESC SV-451- ADMA: Taking Linux Out of the Data Path
This class's general theme is: Taking Linux out of the Data Path for Better Performance. The Linux kernel contains a driver called MD that provides a software RAID facility. Its performance is a fraction of what an SoC with RAID DMA engines can do. The Linux Asynchronous DMA interface was recently created for an SoC to make use of its DMA engines. This class describes how the performance of a RAID system is accelerated by offloading data path tasks to DMA engines using this interface. The resulting high performance Linux RAID driver as well RAID algorithms are discussed in enough detail to provide a working understanding. The impact of page size as well as memory copies are shown. The class is accompanied with a live demonstration of an embedded Linux storage enclosure.