IOANNIS T. SCHOINAS Work Address Home Address Computer Sciences Department 404 #L Eagle Heights University of Wisconsin-Madison Madison, Wisconsin 53706 1210 West Dayton St (608) 231-9974 Madison, Wisconsin 53706 (608) 263-0475 e-mail: schoinas@cs.wisc.edu URL: http://cs.wisc.edu/~schoinas ___________________________________________________________________________________________________________ Objective A career focused on research and development of high performance computer systems. Research Parallel systems, system area networks, operating systems, computer systems architecture. Interests My dissertation work has been focused on the system issues and interfaces involved in building shared memory parallel platforms out of commodity (software and hardware) components. I have also been interested in the implications of novel high-performance I/O devices, such as system-area network interfaces or even 3D graphics accelerators, on the system architecture and the operating system design with regards to the virtual memory subsystem. Education Ph.D. Computer Sciences, University of Wisconsin-Madison, December 1997. Proposed Dissertation title: "Fine-Grain Distributed Shared Memory Systems on Clusters of Workstations." Advisor: Prof. Mark D. Hill. M.S. Computer Science, University of Crete-Heraclion, Greece, July 1991. Master thesis title: "Mercury: A Model for the Implementation of Distributed Data Structures." Advisor: Prof. Stelios Orfanoudakis. B.S. Computer Science, University of Crete-Heraclion, Greece, September 1989. Personal Married, born in Thessaloniki, Greece, 1968. Greek national on F1 Visa ( with practical Information training permit). Fluent in Greek and English. Work Research Assistant, Wisconsin Wind Tunnel (WWT) project, Comp. Sciences Dept., Experience Univ. of Wisc.-Madison, 6/93-present. Chief person responsible for designing and implementing the Blizzard fine-grain distributed shared memory (FGDSM) systems. Blizzard was first implemented on the Thinking Machines CM-5 and later on the Wisconsin Cluster of Workstations (COW), a collection of forty Sun Sparcstations connected through a Myrinet network. FGDSM systems support shared memory in software by controlling memory accesses on a fine-grain basis (64-128 bytes). Blizzard/COW, the focus of my work during the last four years, supports different fine-grain access control techniques and processing policies (multithreaded, 60K lines in C, 500 lines Sparc assembly). A sample list of my work on Blizzard/COW includes: o Designed and implemented Sun Solaris 2.4 loadable kernel modules to support hardware fine-grain access control mechanisms. The core module intercepts internal function pointers and trap vectors to provide extended kernel functionality to hardware-specific drivers without kernel recompiling. It includes a modified segment driver, modified hardware page attributes, and fast trap dispatch ("300 cycles) of synchronous faults to user level. Using its services, the ECC driver provides hardware fine-grain access control using the memory controller's diagnostic mode to set invalid ECC. The core module also supports a hardware-specific driver for a custom fine-grain access control accelerator, which was developed by other members of the WWT group. o Designed and implemented Blizzard's low-latency messaging subsystem. Worked on the device control program, kernel driver and user messaging libraries. Blizzard's messaging is based on Berkeley active messages with two important differences: it supports programs that are not limited to request/reply semantics and it does not require explicit network polling by the application. Designed novel buffer allocation policies to support the extended semantics. Implemented implicit network polling on a cachable memory location by inserting polls directly in the application executable with a binary rewriting tool. o Designed and implemented address translation support for zerocopy protocols on the Myrinet network interface. Extended Blizzard's messaging subsystem to implement software translation structures in the user library or the network interface. Modified the Myrinet device driver to supply the translations and dynamically lock pages as required. Used the implementation as a feasibility demonstration and evaluated different design points using simulations. Teaching Assistant, Comp. Sciences Dept., Univ. of Wis., 09/91-06/93. Worked as a teaching assistant in introductory programming courses. Programmer, Knossos Technologies, Heraclion, Greece 06/92-08/92. Returned to Crete for the summer and worked in a small software company, affiliated with FORTH, to polish POSYBL (see below) for internal use. Research Assistant, Computer Vision and Robotics Laboratory, Institute of Computer Science, FORTH, Greece, 09/89-06/91. Focused on languages and environments for parallel computing. Designed and implemented POSYBL, a port of the Linda parallel programming model on networks of workstations. Designed Mercury, an extended Linda-like model that was influenced by blackboard AI architectures and introduced more flexibility in Linda's search strategies. Assistant Programmer, Computing Center, University of Crete, Greece, 09/86-08/91. Developed system utilities for Vax/VMS and Unix computers. Work Blizzard: Cost-effective Distributed Shared Memory, Ioannis Schoinas, Babak Falsafi, Mark In Progress D. Hill, James R. Larus and David A. Wood, July 1997, Submitted for publication. mailto:schoinas@cs.wisc.edu for a draft copy. Address Translation In Network Interfaces, Ioannis Schoinas and Mark D. Hill, February Publications 1998, 4th International Symposium on High-Performance Computer Architecture. ftp://ftp.cs.wisc.edu/wwt/hpca98_nitrans.os Relaxed Consistency and Coherence Granularity in DSM Systems: A Performance Evaluation, Yuanyuan Zhou, Liviu Iftode, Kai Li, Jaswinder Pal Singh, Brian R. Toonen, Ioannis Schoinas, Mark D. Hill, and David A. Wood, June 1997, The Sixth ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming. ftp://ftp.cs.wisc.edu/wwt/ppopp97_dsmgran.ps Fine-grain Access Control for Distributed Shared Memory, Ioannis Schoinas, Babak Falsafi, Alvin R. Lebeck, Steven K. Reinhardt, James R. Larus and David A. Wood, October 1994, The Sixth International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS VI). Also appears in "Distributed Shared Memory: Concepts and Systems", by Jelica Protic, Milo Tomasevic, Veljko Milutinovic, IEEE Computer Society Press, 1997. ftp://ftp.cs.wisc.edu/wwt/asplos6_fine_grain.ps Application-Specific Protocols for User-Level Shared Memory, Babak Falsafi, Alvin R. Lebeck, Steven K. Reinhardt, Ioannis Schoinas, Mark D. Hill James R. Larus, Anne Rogers and David A. Wood, November 1994, Supercomputing '94. ftp://ftp.cs.wisc.edu/wwt/sc94_protocols.ps POSYBL: PrOgramming SYstem for distributed appLications, Ioannis Schoinas, June 1991, Edinbourg Parallel Computer Center's Workshop on Linda-like systems and their implementations. Technical Implementing Fine-Grain Distributed Shared Memory On Commodity SMP Workstations, Reports Ioannis Schoinas, Babak Falsafi, Mark D. Hill, James R. Larus, Christopher E. Lukas, Shubhendu S. Mukhejee, Steven K. Reinhardt, Eric Schnarr and David A. Wood, March 1996, Technical Report CS-TR-96-1307. ftp://ftp.cs.wisc.edu/pub/tech-reports/reports/96/tr1307.ps.Z Mercury: A Model for the Implementation of Distributed Data Structures, (in Greek with extended English abstract), M.S. thesis, CSD, Univ. of Crete, July 1991. Research Proposed fine-grain distributed shared memory (FGDSM) systems on messaging passing Experience hardware as a low cost solution to provide shared memory. Implemented the first FGDSM system on CM-5. Extended Blizzard (with others) to support Tempest, an interface that allows the implementation of coherence protocols as user-level libraries. Focused on Wisconsin COW and investigated techniques to implement fine-grain access control in commodity workstations. Examined the integration of hardware fine-grain access control within commodity operating systems. Designed a fast trap dispatch interface to quickly deliver fine-grain access faults to user level. Investigated extensions in Berkeley active messages to support protocols that are not limited to request/reply semantics and they do not require explicit polling. Showed that shared memory coherence protocols, while not pure request/reply protocols, have bounded buffer requirements. Evaluated different buffer allocation policies to support the extended active messages. Proposed a buffer allocation policy that does not require buffers in a node's local memory in the common case, yet is robust enough to handle arbitrary traffic streams. Proposed implicit polling using binary rewriting to insert polls in the application code. Investigated the advantages of multiprocessor workstations for FGDSM systems on networks of workstations. Identified the shared resources in fine-grain distributed memory systems to which access should be controlled in an multiprocessor environment. Proposed techniques to address the synchronization issues for each resource based on the frequency of accesses to that resource. Showed that multiprocessor workstations with two processors are more cost-effective for FGDSM systems compared to uniprocessor ones. Investigated address translation in network interfaces to support zerocopy messaging directly to user data structures. Evaluated a series of designs with increasingly higher operating system support requirements. Proposed techniques to take advantage of locality in the source or destination virtual memory addresses, yet degrade gracefully when the capacity of the address translation structures is exceeded. Sample Independent Study, Fall'92 (Wisc). Linda implementation on cooperative shared memory. Course Examine the implications of cooperative shared memory in the development of runtime Project systems for high level programming models. List Architecture & Operating Systems, Spring'92 (Wisc). Linda implementation on the CM-5 message passing multicomputers. It used dynamic (runtime) optimizations to lower the communication overhead in Linda operations. Compilers, Fall'91 (Wisc). Implementation of a compiler for a subset of the Ada programming language. VLSI, Spring'89 (Crete). Design & layout of the DMA channels for an advanced microcontroller with a RISC core using the magic VLSI editor, spice and esim. Architecture, Fall'88 (Crete). Simulator of the datapath and control logic of a simple RISC CPU. Assembly, Spring'87 (Crete). Menu-driven Intel 8086 simulator, with its own macro assembler. Computing Languages: Expert at C, C++, Pascal, FORTRAN. Assembly experience (mostly with Expertise Sparc, but also x86 and MIPS). Knowledge of Lisp, Prolog. Operating Systems: Kernel programming (internals) in Sun Solaris, BSD Unix, Mach OSF/1, Thinking Machines CMOST, Linux. Familiar with Microsoft's operating systems; level-2 member of the Microsoft Developer Network during 3/96-3/97. Familiar with Digital's operating systems. Hardware Platforms: Sun, Digital and HP workstations, IBM PCs, Thinking Machines CM-5, KSR-1, iPSC860, Sequent Symmetry. Professional Conference referee for the SIGCOMM'92, ASPLOS'94, ISCA'95, ISCA'97, HPCA'97. Activities Member of the IEEE Computer Society and the ACM special interest groups SIGARCH, SIGOPS and SIGCOMM. Graduate Univ. of Crete Univ. of Wis.-Madison -------------- --------------------- Course Computer Networks Construction of Compilers Work Machine Learning Advanced Computer Networks VLSI design Advanced Operating Systems Computer Systems Architecture Advanced Computer Architecture II Advanced Topics on Operating Systems Topics in Operating Systems Integrated Services Data Networks Fault Tolerant Computing Advanced Computer Systems Architecture Introduction to Stochastic Processes Computer Vision Computer Systems Performance Artificial Intelligence Marketing Parallel Image Processing Organizational Behavior Special Topics in Computer Vision Lots of research credits References Prof. Mark D. Hill Prof. James R. Larus Prof. David A. Wood Computer Sciences Dept. Computer Sciences Dept. Computer Sciences Dept. Univ. of Wis.- Madison Univ. of Wis.- Madison Univ. of Wis.- Madison 1210 W. Dayton St. 1210 W. Dayton St. 1210 W. Dayton St. Madison, WI 53706 Madison, WI 53706 Madison, WI 53706 Phone : (608) 262-2196 Phone : (608) 262-9519 Phone : (608) 262-7463 FAX : (608) 262-9777 FAX : (608) 262-9777 FAX : (608) 262-9777 Email : markhill@cs.wisc.edu Email : larus@cs.wisc.edu Email : david@cs.wisc.edu Prof. Larus is on sabbatical. He can be reached (8/97-9/98): Microsoft Corporation One Microsoft Way Redmond, WA 98052. Phone : (425) 936-2981 Email : larus@microsoft.com