Capo: An Operating System Interface for Practical Deterministic Multiprocessor Replay

To be practical, systems for deterministic replay of multiprocessor programs need to support an environment with multiple parallel jobs running concurrently – some being recorded, others being replayed and even others running without recording or replay. The system also needs to manage limited-size log buffers. Finally, the system needs to have very low overhead, likely leveraging special-purpose logging hardware.

In the Capo project, we address these shortcomings by introducing, for the first time, a set of abstractions and a software-hardware interface for practical hardware-assisted replay of multiprocessor systems. We introduce the novel abstraction of the Replay Sphere to separate the responsibilities of the hardware and software components of the replay system. In this talk, we will focus on the software aspects of the problem, and discuss our experiences in building a prototype called CapoOne implemented on Linux.

Speaker Details

Josep Torrellas (http://iacoma.cs.uiuc.edu) is a Professor and Willett Faculty Scholar at the University of Illinois. Prior to being at Illinois, Torrellas received a PhD from Stanford University.He also spent a year IBM’s T.J. Watson Research Center. Torrellas’s research area is multiprocessor computer architecture. He leads the Illinois Aggressive COMA Multiprocessor group. He has been involved in the Stanford DASH and the Illinois Cedar multiprocessor projects. He has contributed extensively in the area of shared-memory multiprocessor architecture, thread-level speculation, debugging and programmability tools, hardware reliability, and software dependability. He received an NSF Young Investigator Award and several best-paper awards. He is an IEEE Fellow.

Samuel King (http://www.cs.uiuc.edu/~kingst) and Josep Torrellas (http://iacoma.cs.uiuc.edu) are professors at the Computer Science Department of the University of Illinois. They have been working on various aspects of deterministic replay of programs from hardware and software points of view for several years. Their most recent work on this topic appears in ASPLOS 2009.

Date:
Speakers:
Josep Torrellas and Samuel King
Affiliation:
Computer Science Department Univ. of Illinois, Urbana-Champaign