Department of Information Technology

21st Century Computer Architecture


Mark D. Hill, University of Wisconsin

Date and Time

Monday, September 16th, 2013 at 10:15.


Polacksbacken, room 1145


This talk--suitable for a wide CS audience--has two parts. The first part will discuss possible directions for computer architecture research, including architecture as infrastructure, energy first, impact of new technologies, and
cross-layer opportunities. This part is based on a 2012 Computing Community Consortium (CCC) whitepaper effort led by Hill.

The second part of the talk is an example of the cross-layer research advocated in the first part. Analysis shows that many “big-memory” server workloads, such as databases, in-memory caches, and graph analytics, pay a high cost for page-based virtual memory: up to 50% of execution time wasted.

Via small changes to the operating system (Linux) and hardware (x86-64 MMU), this work reduces execution time these workloads waste to less than 0.5%. The key idea is to map part of a process’s linear virtual address space with a new incarnation of segmentation, while providing compatibility by mapping the rest of the virtual address space with paging (See ISCA 2013 paper).

About the speaker

Biography: Mark D. Hill ( is the Gene M.
Amdahl Professor of Computer Sciences and Electrical & Computer Engineering
at the University of Wisconsin--Madison, where he also co-leads the
Wisconsin Multifacet (
project. His research interests include parallel computer system design,
memory system design, computer simulation, deterministic replay and
transactional memory. He earned a PhD from University of California,
Berkeley. He is an ACM Fellow, a Fellow of the IEEE, co-inventor on 30+
patents, and ACM SIGARCH Distinguished Service Award recipient.

Updated  2013-09-09 14:35:53 by Frédéric Haziza.