1. Your Speaker in a Nutshell BA in Economics 1965 PhD University of CA, Berkeley 1989 Technical skills and innovations that married architecture & compilers. Mostly collaborations. Pushed for quality over quantity, technology transfer & impact I have always loved my job. Thesis: better understanding of sharing behavior MVP: Simultaneous Multithreading Current work: a new life for dataflow machines Transitioning to retirement (golf, gardening & landscaping, food snob). Susan Eggers: SOSP Women's Workshop

2. Challenge in Computer Architecture There’s one biggie: programs run faster Susan Eggers: SOSP Women's Workshop

3. The Underlying Cause Susan Eggers: SOSP Women's Workshop

4. How Architects are Addressing the Challenge Some things we have some idea how to do: • More aggressive speculation (threads, memory, value) • More aggressive recovery mechanisms (transactional memory) • Lighter-weight locking mechanisms • Exploiting super-fine-grain parallelism with dataflow execution • Adding a few more processors • The engineering: building hardware for sharing and concurrency Susan Eggers: SOSP Women's Workshop

5. How Architects are Addressing the Challenge Some things we have not a clue about: • Writing parallel codes for 100s or 1000s of processors • Discovering other than embarrassingly parallel, coarse-grain parallelism • Determining the best programming model for writing parallel codes • Should the programmer detect parallelism or should the compiler do it automatically? • Devising language constructs to express parallelism • Exploiting the concurrency once we’ve discovered it • Avoiding race conditions, deadlock, livelock • Doing all this in a way that is simple and intuitive for the programmer Susan Eggers: SOSP Women's Workshop

6. How Architects are Addressing the Challenge Some things we have not a clue about: • Executing with 100s or 1000s of processors • Making good trade-offs between load balancing & locality • Recovering from failing processors (RAID issues) Susan Eggers: SOSP Women's Workshop

7. Rules of Thumb for Picking New Research Projects How to develop a nose for good research ideas. What in the underlying technology or application space has changed? • How has it changed? How does that affect my area of interest? • In what areas can I no longer do business as usual? • Where are the new performance bottlenecks? • What opportunities does the change bring? • What technology or techniques that went out of style can be resurrected? Caveat: technology trends don’t always turn out the way you expect • CCDs failed in computers; Prologue failed • Are supercomputers failing? • Will quantum and DNA computing succeed? Susan Eggers: SOSP Women's Workshop

8. Examples of OS Research that are Driven by Computer Architecture The operating system: • How do you design an OS for 1000s of processors? • How do current OSs hinder scalability? Where are the bottlenecks? Where are the centralized software structures? • Do you start from scratch? • Great opportunity to design free of tradition & an industry standard • What should be the key design criteria? • Do you use virtual machines to execute programs on small clusters of processors and then build a programming environment that hides that? Susan Eggers: SOSP Women's Workshop

9. Examples of OS Research that are Driven by Computer Architecture Transactional memory: • How should programs written with transactions interface with the OS? • What does rollback mean over a network? Security: • What if everyone is a parallel programmer? • latent concurrency bugs, deadlock, livelock • What are the implications for security? Susan Eggers: SOSP Women's Workshop

10. Examples of OS Research that are Driven by Computer Architecture Fine-grain threads: • The OS has to support more than pthreads. • How fine-grain can/should they be? • And stepping back, what is a thread? Can it be data centric? Virtual machine support in hardware: • What if virtual machines were very light-weight? • What might you use them for and how? • Can a virtual machine replace a process? a protection domain? Susan Eggers: SOSP Women's Workshop

11. Examples of OS Research that are Driven by Something Else New applications: • How will Google’s needs change the OS? • How should the OS manage fast I/O between CPUs (10Gb)? • How can the OS make up for its absence? Phase-change memory (fast, non-volatile, but high power) How would you build a file system if you didn’t need disks? Third-world computing: • Low-cost, low-power, multi-lingual, multiple education levels, different apps • What does the OS look like? More powerful processor, same number of pins? • How do you feed it? Susan Eggers: SOSP Women's Workshop