ICSA Colloquium Talk - 30/04/2024

Talk Title: Reinventing virtual memory for modern hardware

Paged-based virtual memory forms the basis of memory management in modern hardware, and has in the past decades been extended with support for accelerators and I/O devices. As memory sizes grow to terabytes and beyond, though, the complexity and overhead of address translation has become costly.

My research group has been tackling this problem for more than a decade, looking for ways to provide the flexibility and benefit of paged-based memory at greater efficiencies. In this talk, I will cover our recent work on how to adapt virtual memory mechanisms in hardware and software for modern computing environments. First, I will cover a new software approach to memory management, Cost-Based Memory Management (CBMM) that tries to balance the cost of operating system memory operations against the benefit to applications. We found that Linux can spend hundreds of milliseconds allocating a single huge page of memory, who's benefit is typically a few milliseconds in performance gains. Second, I'll talk about BypassD, which leverages virtual memory hardware to enable low-latency access to storage. It uses memory protection to allow user-space access to files without kernel interference on the datapath, which greatly improves performance on low-latency devices.

Bio: Michael Swift is a professor at the University of Wisconsin--Madison. His research focuses on the hardware/operating system boundary, including virtual memory, persistence and storage, new compute technologies, and device drivers. He received his BA from Cornell University in 1992 and Ph.D. from the University of Washington in 2005. Before graduate school, he worked at Microsoft in the Windows group, where he implemented authentication and access control functionality in Windows Cairo, Windows NT, and Windows 2000.