Efficient management of large DMA memory buffers in microdrivers

Microdrivers run entirely in user space. The paradigm of such user-space device drivers has already shown to improve reliability and portability over pure kernel-space drivers. While the microdriver approach has been successful so far for low throughput and high latency use-cases such as USB, little research has been done on high performance applications. The Portable Driver Architecture (PDA) is a library which supports programming of microdrivers for high-speed PCI devices. This paper presents how it is possible to simplify large DMA buffer handling by using I/O Memory Management Units (IOMMU). Additionally, we optimized our library for intra-node communication in non-uniform memory access architectures.