Emery Berger

Professor, Computer Science, Univ. of Massachusetts Amherst. My students, collaborators, and I in the PLASMA lab build innovative and impactful systems, especially focused on performance, reliability, and security. Among other things, I am also the creator/maintainer of https://CSrankings.org. For the academic year 2023/2024, I am on sabbatical and am an Amazon Scholar at Amazon Web Services.

Recent blog posts

• Coping with CoPilot (SIGARCH/SIGPLAN)
• Drop Whatever You're Researching and Start Working on Crypto! (SIGARCH)
• A Checklist Manifesto for Empirical Evaluation (SIGARCH/SIGPLAN)
  (SIGPLAN Empirical Evaluation Checklist PDF)

Links

• PLASMA lab GitHub:
• Personal GitHub:
• Mastodon:
• Twitter: @emeryberger
• YouTube:
• emeryberger.com, Medium blog
• Publications: Google Scholar, DBLP

Selected software from me and my collaborators (for a full list, see PLASMA)

• Scalene: A state-of-the-art CPU+GPU+memory profiler for Python, with AI-powered optimization suggestions
  
• Coz: A causal profiler that tells you where to optimize your code (C/C++/Rust/Swift/Java)
  (just counting Rust crate downloads)
• CSrankings: Ranks the world's CS departments
  
• Slipcover: Nearly zero-overhead code coverage analysis for Python
  
• ChatDBG: AI-assisted debugging in lldb, gdb, and pdb. Uses AI to answer 'why'
  
• Commentator: Automatically comments Python code, adding docstrings and type annotations
  
• CWhy: ("See why") Explains and suggests fixes for C/C++/Rust compiler error messages.
  
• SQLwrite: SQLite3 with natural language to SQL, recommends indexes to optimize queries
  

Selected Talks

Performance Matters (Strange Loop 2019)
The second most popular Strange Loop video of all time!

Python Performance Matters (Strange Loop 2022)

Scalene (PyCon 2021)

How to Get Your Research Adopted (PLDI keynote)

Selected Papers

• Triangulating Python Performance with Scalene (OSDI 2023, Best Paper Award)
  Introduces Scalene, a profiler that highlights Python performance issues. [software]
• Coz: Finding Code that Counts with Causal Profiling (Best Paper Award SOSP 2015, CACM Research Highlight)
  Introduces causal profiling and the Coz profiler. [software]
• Mesh: Compacting Memory Management for C/C++ Applications (PLDI 2019)
  A drop-in replacement for malloc that eliminates fragmentation. [software]
• BLeak: Automatically Debugging Memory Leaks in Web Applications (PLDI 2018, CACM Research Highlight)
  Detects memory leaks in web applications automatically. [software] incorporated into Android Studio
• Stabilizer: Statistically Sound Performance Evaluation (ASPLOS 2013)
  Randomizes everything to see if performance changes are real. incorporated into WebAssembly benchmarking infrastructure
• Reconsidering Custom Memory Allocation (OOPSLA 2012, Most Influential Paper)
  Shows which kinds of custom memory allocators are useful for improving performance (TL;DR - not many).
• Hoard: A Scalable Memory Allocator for Multithreaded Applications (ASPLOS 2000, ASPLOS Most Influential Paper)
  The first scalable malloc. [software] incorporated into the Mac OS X allocator

Bio

Emery Berger is a Professor in the Manning College of Information and Computer Sciences at the University of Massachusetts Amherst, the flagship campus of the UMass system. He graduated with a Ph.D. in Computer Science from the University of Texas at Austin in 2002. Professor Berger has been a Visiting Scientist at Microsoft Research and at the Universitat Politècnica de Catalunya (UPC) / Barcelona Supercomputing Center (BSC).

Professor Berger’s research spans programming languages, runtime systems, and operating systems, with a particular focus on systems that transparently improve reliability, security, and performance. He and his collaborators have created a number of influential software systems including Hoard, a fast and scalable memory manager that accelerates multithreaded applications (used by companies including British Telecom, Cisco, Crédit Suisse, Reuters, Royal Bank of Canada, SAP, and Tata, and on which the Mac OS X memory manager is based); DieHard, an error-avoiding memory manager that directly influenced the design of the Windows 7 Fault-Tolerant Heap; and DieHarder, a secure memory manager that was an inspiration for hardening changes made to the Windows 8 heap (see this map of the landscape of memory management research for an overview). He also created and maintains the widely-used CSrankings website.

His honors include a Microsoft Research Fellowship, an NSF CAREER Award, a Lilly Teaching Fellowship, the Distinguished Artifact Award for PLDI 2014, the Most Influential Paper Award at OOPSLA 2012, the Most Influential Paper Award at PLDI 2016, the ASPLOS 2019 Influential Paper Award, five SIGPLAN Research Highlights, five CACM Research Highlights (1, 2, 3, 4, 5), a Google Research Award, a Microsoft SEIF Award, and Best Paper Awards at FAST, OOPSLA, and SOSP. Professor Berger served two terms (1, 2) as an elected member of the SIGPLAN Executive Committee; he served for a decade (2007-2017) as Associate Editor of the ACM Transactions on Programming Languages and Systems, was Program Chair for PLDI 2016, and served as co-Program Chair of ASPLOS 2021. He was named an ACM Fellow in 2019.