Stephanie Wang

dblp:175/6757 · DBLP profile ↗
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29ranked-venue papers
4as first author
20since 2021 · last 2025
—ORCID · conflict

Domains — the database's venue-derived domains; a paper can count in several

Software engineering, systems software and programming languages · 8 · 2 first-author · 4 since 2021Graphics, computer vision, multimedia, augmented reality and games · 7 · 1 first-author · 6 since 2021Computer networks · 5 · 1 first-author · 5 since 2021Artificial intelligence and machine learning · 4 · 2 since 2021Databases, data management, data science and information retrieval · 3 · 3 since 2021Human-computer interaction and ubiquitous computing · 2 · 1 since 2021Systems, architecture and hardware · 1 · 1 since 2021Security and privacy · 1
YearPublicationVenuePosition
2025 Programmable and Adaptive Scheduling for Distributed Systems
abstract
Existing frameworks for managing distributed systems hard-code scheduling policies and their implementations (e.g., centralized vs. decentralized), limiting customization and hurting performance across diverse applications and workloads. We argue for an adaptive scheduling approach, where developers express policies in a high-level, framework-agnostic DSL, and a compiler generates optimized implementations based on policy semantics, workload characteristics, and execution environments. We demonstrate that our compiler-guided approach can significantly improve both scheduling quality and performance.
Xiangfeng Zhu, Ratul Mahajan, Stephanie Wang
HotNets4
2025 Towards ML System Extensibility
abstract
With the rise of large language models, distributed execution across multiple accelerators has become commonplace. Current ML systems must adopt complex distributed execution strategies for efficiency, but do so at the cost of extensibility. We believe that it is time to introduce a general-purpose distributed runtime for programming clusters of accelerators that enables: (1) placement flexibility, and (2) interoperability, without sacrificing (3) codesign. We propose using the DAFT API: distributed actors, futures, and tasks. To enable a smooth tradeoff between flexibility vs. performance, we introduce two execution modes: interpreted vs. compiled. We show how current applications in LLM inference and training can be executed as interpreted and compiled DAFT programs and discuss open questions and challenges.
Weixin Deng, Andy Ruan, Megan Frisella, Kai-Hsun Chen, SangBin Cho, Jack Tigar Humphries, Stephanie Wang
HotOS8
2025 NanoFlow: Towards Optimal Large Language Model Serving Throughput
Kan Zhu, Yilong Zhao 0002, Liangyu Zhao, Gefei Zuo, Yile Gu, Dedong Xie, Zihao Ye 0001, Keisuke Kamahori, Chien-Yu Lin, Ziren Wang, Stephanie Wang, Arvind Krishnamurthy, Baris Kasikci
OSDI12
2025 Variational Neural Surfacing of 3D Sketches
abstract
3D sketches are an effective representation of a 3D shape, convenient to create via modern Virtual or Augmented Reality (VR/AR) interfaces or from 2D sketches. For 3D sketches drawn by designers, human observers can consistently imagine the surface they imply, yet reconstructing such a surface with modern methods remains an open problem. Existing methods either assume a clean, well-structured 3D curve network (while in reality most 3D sketches are rough and unstructured), or make no effort to produce a surface consistent with perceptual observations. We propose a novel method that addresses this challenge by designing a system that reconstructs a surface that better aligns with human perception from a clean or rough set of 3D sketches. As the topology of the desired surface is unknown, we use an implicit neural surface representation, parameterized via its gradient field.
Stephanie Wang, Mikhail Bessmeltsev
SIGGRAPH Asia2
2025 Implicit UVs: Real-time semi-global parameterization of implicit surfaces
abstract
Abstract Implicit representations of shapes are broadly used in computer graphics since they offer many valuable properties in design, modeling, and animation. However, their implicit and volumetric nature makes applying 2D textures fundamentally challenging. We propose a method to compute point‐wise and parallelizable semi‐global parameterizations of implicit surfaces for texturing, rendering, and modeling purposes. Our method not only defines local patches of parameterization, but also enables the merging of multiple adjacent patches into large and spatially coherent ones that conform to the geometry. Implemented in shaders into a sphere‐tracing pipeline, our method allows users to edit the uv‐fields with real‐time visualization. We demonstrate how to add rendering details (texture, normal, displacement, etc.) using our parameterization, as well extending modeling tools with implicit shell maps. Furthermore, the textured objects remain implicit and can still be used in a modeling pipeline.
Baptiste Genest, Pierre Gueth, Jérémy Levallois, Stephanie Wang
Comput. Graph. Forum4
2024 MotherDuck: DuckDB in the cloud and in the client
R. J. Atwal, Peter Boncz, Ryan Boyd, Antony Courtney, Till Döhmen, Florian Gerlinghoff, Jeff Huang 0007, Joseph Hwang, Raphael Hyde, Elena Felder, Jacob Lacouture, Yves Le Maout, Boaz Leskes, Alex Monahan, Dan Perkins, Tino Tereshko, Jordan Tigani, Nick Ursa, Stephanie Wang, Yannick Welsch
CIDR20
2024 DataComp-LM: In search of the next generation of training sets for language models
abstract
We introduce DataComp for Language Models, a testbed for controlled dataset experiments with the goal of improving language models.As part of DCLM, we provide a standardized corpus of 240T tokens extracted from Common Crawl, effective pretraining recipes based on the OpenLM framework, and a broad suite of 53 downstream evaluations.Participants in the DCLM benchmark can experiment with data curation strategies such as deduplication, filtering, and data mixing atmodel scales ranging from 412M to 7B parameters.As a baseline for DCLM, we conduct extensive experiments and find that model-based filtering is key to assembling a high-quality training set.The resulting dataset, DCLM-Baseline, enables training a 7B parameter language model from scratch to 63% 5-shot accuracy on MMLU with 2T training tokens.Compared to MAP-Neo, the previous state-of-the-art in open-data language models, DCLM-Baseline represents a 6 percentage point improvement on MMLU while being trained with half the compute.Our results highlight the importance of dataset design for training language models and offer a starting point for further research on data curation. We release the \dclm benchmark, framework, models, and datasets at https://www.datacomp.ai/dclm/
Jeffrey Li, Alex Fang, Georgios Smyrnis, Maor Ivgi, Matt Jordan, Samir Yitzhak Gadre, Hritik Bansal, Etash Kumar Guha, Sedrick Keh, Kushal Arora, Niklas Muennighoff, Reinhard Heckel, Jean Mercat, Mayee F. Chen, Suchin Gururangan, Mitchell Wortsman, Alon Albalak, Yonatan Bitton, Marianna Nezhurina, Amro Abbas, Cheng-Yu Hsieh, Dhruba Ghosh, Josh Gardner 0001, Maciej Kilian, Hanlin Zhang 0002, Rulin Shao, Sarah M. Pratt, Sunny Sanyal, Gabriel Ilharco, Giannis Daras, Kalyani Marathe, Aaron Gokaslan, Jieyu Zhang 0001, Khyathi Raghavi Chandu, Igor Vasiljevic, Sham M. Kakade, Shuran Song, Sujay Sanghavi, Fartash Faghri, Sewoong Oh, Luke Zettlemoyer, Kyle Lo, Alaaeldin El-Nouby, Hadi Pouransari, Alexander Toshev, Stephanie Wang, Dirk Groeneveld, Luca Soldaini, Pang Wei Koh, Jenia Jitsev, Thomas Kollar, Alexandros G. Dimakis, Yair Carmon, Achal Dave, Ludwig Schmidt, Vaishaal Shankar
NeurIPS49
2023 Logical Memory Pools: Flexible and Local Disaggregated Memory
abstract
We propose logical memory pools, a memory disaggregation architecture for the emerging Compute Express Link (CXL) technology in datacenters. The key idea is to create a memory pool by carving out parts of the local memory in each server, rather than using a physical memory pool that is separate from servers. Logical pools provide significant benefits over physical pools, namely, lower cost, support for near-memory computing without extra hardware, and flexibility on designating whether memory is part of the memory pool or not. We demonstrate that logical pools can execute workloads that are unfeasible in physical pools, and that its faster access leads to better performance. Realizing logical memory pools poses five major challenges, which we believe can be overcome. Given the benefits of logical pools, we believe the CXL community should refocus efforts on logical, rather than physical memory pools.
Emmanuel Amaro, Stephanie Wang, Aurojit Panda, Marcos K. Aguilera
HotNets2
2023 ExoFlow: A Universal Workflow System for Exactly-Once DAGs
Siyuan Zhuang, Stephanie Wang, Eric Liang, Ion Stoica
OSDI2
2023 Exoshuffle: An Extensible Shuffle Architecture
abstract
Shuffle is one of the most expensive communication primitives in distributed data processing and is difficult to scale. Prior work addresses the scalability challenges of shuffle by building monolithic shuffle systems. These systems are costly to develop, and they are tightly integrated with batch processing frameworks that offer only high-level APIs such as SQL. New applications, such as ML training, require more flexibility and finer-grained interoperability with shuffle. They are often unable to leverage existing shuffle optimizations.
Sifei Luan 0001, Stephanie Wang, Samyukta Yagati, Sean Kim, Kenneth Lien, Isaac Ong, Tony Hong, SangBin Cho, Eric Liang, Ion Stoica
SIGCOMM2
2023 Fluid Cohomology
abstract
The vorticity-streamfunction formulation for incompressible inviscid fluids is the basis for many fluid simulation methods in computer graphics, including vortex methods, streamfunction solvers, spectral methods, and Monte Carlo methods. We point out that current setups in the vorticity-streamfunction formulation are insufficient at simulating fluids on general non-simply-connected domains. This issue is critical in practice, as obstacles, periodic boundaries, and nonzero genus can all make the fluid domain multiply connected. These scenarios introduce nontrivial cohomology components to the flow in the form of harmonic fields. The dynamics of these harmonic fields have been previously overlooked. In this paper, we derive the missing equations of motion for the fluid cohomology components. We elucidate the physical laws associated with the new equations, and show their importance in reproducing physically correct behaviors of fluid flows on domains with general topology.
Mohammad Sina Nabizadeh, Baichuan Wu, Stephanie Wang, Albert Chern
ACM Trans. Graph.4
2022 ESCHER: expressive scheduling with ephemeral resources
abstract
As distributed applications become increasingly complex, so do their scheduling requirements. This development calls for cluster schedulers that are not only general, but also evolvable. Unfortunately, most existing cluster schedulers are not evolvable: when confronted with new requirements, they need major rewrites to support these requirements. Examples include gang-scheduling support in Kubernetes [6, 39] or task-affinity in Spark [39]. Some cluster schedulers [14, 30] expose physical resources to applications to address this. While these approaches are evolvable, they push the burden of implementing scheduling mechanisms in addition to the policies entirely to the application.
Romil Bhardwaj, Alexey Tumanov, Stephanie Wang, Richard Liaw, Philipp Moritz, Robert Nishihara, Ion Stoica
SoCC3
2022 DeepCurrents: Learning Implicit Representations of Shapes with Boundaries
abstract
Recent techniques have been successful in reconstructing surfaces as level sets of learned functions (such as signed distance fields) parameterized by deep neural networks. Many of these methods, however, learn only closed surfaces and are unable to reconstruct shapes with boundary curves. We propose a hybrid shape representation that combines explicit boundary curves with implicit learned interiors. Using machinery from geometric measure theory, we parameterize currents using deep networks and use stochastic gradient descent to solve a minimal surface problem. By modifying the metric according to target geometry coming, e.g., from a mesh or point cloud, we can use this approach to represent arbitrary surfaces, learning implicitly defined shapes with explicitly defined boundary curves. We further demonstrate learning families of shapes jointly parameterized by boundary curves and latent codes.
David R. Palmer 0001, Dmitriy Smirnov 0001, Stephanie Wang, Albert Chern, Justin Solomon 0001
CVPR3
2022 Covector fluids
abstract
The animation of delicate vortical structures of gas and liquids has been of great interest in computer graphics. However, common velocity-based fluid solvers can damp the vortical flow, while vorticity-based fluid solvers suffer from performance drawbacks. We propose a new velocity-based fluid solver derived from a reformulated Euler equation using covectors. Our method generates rich vortex dynamics by an advection process that respects the Kelvin circulation theorem. The numerical algorithm requires only a small local adjustment to existing advection-projection methods and can easily leverage recent advances therein. The resulting solver emulates a vortex method without the expensive conversion between vortical variables and velocities. We demonstrate that our method preserves vorticity in both vortex filament dynamics and turbulent flows significantly better than previous methods, while also improving preservation of energy.
Mohammad Sina Nabizadeh, Stephanie Wang, Ravi Ramamoorthi, Albert Chern
ACM Trans. Graph.2
2021 Everything is a Transaction: Unifying Logical Concurrency Control and Physical Data Structure Maintenance in Database Management Systems
Matthew Butrovich, Tianyu Li 0001, Andrew Pavlo, Yash Nannapaneni, John Rollinson, Huanchen Zhang, Ambarish Balakumar, Daniel Biales, Ziqi Dong, Emmanuel J. Eppinger, Jordi E. Gonzalez, Wan Shen Lim, Jianqiao Liu, Lin Ma 0006, Prashanth Menon, Soumil Mukherjee, Tanuj Nayak, Amadou Ngom, Dong Niu, Deepayan Patra, Poojita Raj, Stephanie Wang, Wuwen Wang, William Zhang 0001
CIDR23
2021 In reference to RPC: it's time to add distributed memory
abstract
RPC has been remarkably successful. Most distributed applications built today use an RPC runtime such as gRPC [3] or Apache Thrift [2]. The key behind RPC's success is the simple but powerful semantics of its programming model. In particular, RPC has no shared state: arguments and return values are passed by value between processes, meaning that they must be copied into the request or reply. Thus, arguments and return values are inherently immutable. These simple semantics facilitate highly efficient and reliable implementations, as no distributed coordination is required, while remaining useful for a general set of distributed applications. The generality of RPC also enables interoperability: any application that speaks RPC can communicate with another application that understands RPC.
Stephanie Wang, Benjamin Hindman, Ion Stoica
HotOS1
2021 Ownership: A Distributed Futures System for Fine-Grained Tasks
Stephanie Wang, Eric Liang, Edward Oakes, Benjamin Hindman, Sifei Luan 0001, Audrey Cheng, Ion Stoica
NSDI1
2021 Hoplite: efficient and fault-tolerant collective communication for task-based distributed systems
abstract
Task-based distributed frameworks (e.g., Ray, Dask, Hydro) have become increasingly popular for distributed applications that contain asynchronous and dynamic workloads, including asynchronous gradient descent, reinforcement learning, and model serving. As more data-intensive applications move to run on top of task-based systems, collective communication efficiency has become an important problem. Unfortunately, traditional collective communication libraries (e.g., MPI, Horovod, NCCL) are an ill fit, because they require the communication schedule to be known before runtime and they do not provide fault tolerance.
Siyuan Zhuang, Zhuohan Li 0001, Danyang Zhuo, Stephanie Wang, Eric Liang, Robert Nishihara, Philipp Moritz, Ion Stoica
SIGCOMM4
2021 Rearchitecting In-Memory Object Stores for Low Latency
abstract
Low latency is increasingly critical for modern workloads, to the extent that compute functions are explicitly scheduled to be co-located with their in-memory object stores for faster access. However, the traditional object store architecture mandates that clients interact with the server via inter-process communication (IPC). This poses a significant performance bottleneck for low-latency workloads. Meanwhile, in many important emerging AI workloads, such as parallel tree search and reinforcement learning, all the worker processes accessing the object store belong to a single user. We design Lightning, an in-memory object store rearchitected for modern, low-latency workloads in a single-user, multi-process setting. Lightning departs from the traditional design by adopting a shared memory model, enabling clients to directly access the object store without IPC boundary. Instead, client isolation is achieved by a novel integration of Intel Memory Protect Keys (MPK) hardware, transaction logging, and formal verification. Our evaluations show that Lightning outperforms state-of-the-art in-memory object stores by up to 9.0x on five standard NoSQL workloads and up to 4.5x in scaling up a Python tree search program. Lightning improves the throughput of a popular reinforcement learning framework that uses an in-memory object store for data sharing by up to 40%.
Danyang Zhuo, Kaiyuan Zhang 0001, Zhuohan Li 0001, Siyuan Zhuang, Stephanie Wang, Ang Chen 0001, Ion Stoica
Proc. VLDB Endow.5
2021 Computing minimal surfaces with differential forms
abstract
We describe a new algorithm that solves a classical geometric problem: Find a surface of minimal area bordered by an arbitrarily prescribed boundary curve. Existing numerical methods face challenges due to the non-convexity of the problem. Using a representation of curves and surfaces via differential forms on the ambient space, we reformulate this problem as a convex optimization. This change of variables overcomes many difficulties in previous numerical attempts and allows us to find the global minimum across all possible surface topologies. The new algorithm is based on differential forms on the ambient space and does not require handling meshes. We adopt the Alternating Direction Method of Multiplier (ADMM) to find global minimal surfaces. The resulting algorithm is simple and efficient: it boils down to an alternation between a Fast Fourier Transform (FFT) and a pointwise shrinkage operation. We also show other applications of our solver in geometry processing such as surface reconstruction.
Stephanie Wang, Albert Chern
ACM Trans. Graph.1
2020 Practical Volume-Based Attacks on Encrypted Databases
abstract
Recent years have seen an increased interest towards strong security primitives for encrypted databases (such as oblivious protocols) that hide the access patterns of query execution and reveal only the volume of results. However recent work has shown that even volume leakage can enable the reconstruction of entire columns in the database. Yet existing attacks rely on a set of assumptions that are unrealistic in practice for example they (i) require a large number of queries to be issued by the user or (ii) assume certain distributions on the queries or underlying data (e.g. that the queries are distributed uniformly at random or that the database does not contain missing values). In this work we present new attacks for recovering the content of individual user queries assuming no leakage from the system except the number of results and avoiding the limiting assumptions above. Unlike prior attacks our attacks require only a single query to be issued by the user for recovering the keyword. Furthermore our attacks make no assumptions about the distribution of issued queries or the underlying data. Instead our key insight is to exploit the behavior of real-world applications. We start by surveying 11 applications to identify two key characteristics that can be exploited by attackers-(l) file injection and (ii) automatic query replay. We present attacks that leverage these two properties in concert with volume leakage independent of the details of any encrypted database system. Subsequently we perform an attack on the real Gmail web client by simulating a server-side adversary. Our attack on Gmail completes within a matter of minutes demonstrating the feasibility of our techniques. We also present three ancillary attacks for situations when certain mitigation strategies are employed.
Rishabh Poddar, Stephanie Wang, Jianan Lu, Raluca A. Popa
EuroS&P2
2019 Lineage stash: fault tolerance off the critical path
abstract
As cluster computing frameworks such as Spark, Dryad, Flink, and Ray are being deployed in mission critical applications and on larger and larger clusters, their ability to tolerate failures is growing in importance. These frameworks employ two broad approaches for fault tolerance: checkpointing and lineage. Checkpointing exhibits low overhead during normal operation but high overhead during recovery, while lineage-based solutions make the opposite tradeoff.
Stephanie Wang, John Liagouris, Robert Nishihara, Philipp Moritz, Ujval Misra, Alexey Tumanov, Ion Stoica
SOSP1
2019 A thermomechanical material point method for baking and cooking
abstract
We present a Material Point Method for visual simulation of baking breads, cookies, pancakes and similar materials that consist of dough or batter (mixtures of water, flour, eggs, fat, sugar and leavening agents). We develop a novel thermomechanical model using mixture theory to resolve interactions between individual water, gas and dough species. Heat transfer with thermal expansion is used to model thermal variations in material properties. Water-based mass transfer is resolved through the porous mixture, gas represents carbon dioxide produced by leavening agents in the baking process and dough is modeled as a viscoelastoplastic solid to represent its varied and complex rheological properties. Water content in the mixture reduces during the baking process according to Fick's Law which contributes to drying and cracking of crust at the material boundary. Carbon dioxide gas produced by leavening agents during baking creates internal pressure that causes rising. The viscoelastoplastic model for the dough is temperature dependent and is used to model melting and solidification. We discretize the governing equations using a novel Material Point Method designed to track the solid phase of the mixture.
Mengyuan Ding, Xuchen Han, Stephanie Wang, Theodore F. Gast, Joseph Teran
ACM Trans. Graph.3
2018 Training Classifiers with Natural Language Explanations
abstract
Training accurate classifiers requires many labels, but each label provides only limited information (one bit for binary classification). In this work, we propose BabbleLabble, a framework for training classifiers in which an annotator provides a natural language explanation for each labeling decision. A semantic parser converts these explanations into programmatic labeling functions that generate noisy labels for an arbitrary amount of unlabeled data, which is used to train a classifier. On three relation extraction tasks, we find that users are able to train classifiers with comparable F1 scores from 5-100× faster by providing explanations instead of just labels. Furthermore, given the inherent imperfection of labeling functions, we find that a simple rule-based semantic parser suffices.
Braden Hancock, Paroma Varma, Stephanie Wang, Martin Bringmann, Percy Liang, Christopher Ré
ACL (1)3
2018 Garment-based EMG system for intra-spacesuit biomechanics analysis
abstract
The mechanism of astronaut injuries inside rigid spacesuits is not well understood, due to difficulty visualizing intra-spacesuit body motions. An alternative method is to record muscle activation signals with electromyography (EMG); however, the conventional EMG procedure requires bulky, extensive electrode/wire setup and is susceptible to signal noise. To address these challenges for aerospace applications of EMG, we designed a garment-based system to collect EMG data from upper body muscle activities inside spacesuits. Constructed with form-fitting textiles and careful management of on-garment tensions, our garment provides a viable non-invasive EMG study solution that maximizes applicability and subject mobility while resisting motion artifacts. The functionality and usability of our design was also validated with a human subject test, which showed standard-quality signal, easy don/doff process, minimal electrode/wire setup, and simple wire bulk management, as opposed to the conventional methods.
J. Walter Lee, Stephanie Wang, Caroline Albers, Lucy E. Dunne
UbiComp2
2018 Learning to Play With Intrinsically-Motivated, Self-Aware Agents
abstract
Infants are experts at playing, with an amazing ability to generate novel structured behaviors in unstructured environments that lack clear extrinsic reward signals. We seek to mathematically formalize these abilities using a neural network that implements curiosity-driven intrinsic motivation. Using a simple but ecologically naturalistic simulated environment in which an agent can move and interact with objects it sees, we propose a "world-model" network that learns to predict the dynamic consequences of the agent's actions. Simultaneously, we train a separate explicit "self-model" that allows the agent to track the error map of its world-model. It then uses the self-model to adversarially challenge the developing world-model. We demonstrate that this policy causes the agent to explore novel and informative interactions with its environment, leading to the generation of a spectrum of complex behaviors, including ego-motion prediction, object attention, and object gathering. Moreover, the world-model that the agent learns supports improved performance on object dynamics prediction, detection, localization and recognition tasks. Taken together, our results are initial steps toward creating flexible autonomous agents that self-supervise in realistic physical environments.
Nick Haber, Damian Mrowca, Stephanie Wang, Li Fei-Fei 0001, Dan Yamins
NeurIPS3
2018 Ray: A Distributed Framework for Emerging AI Applications
Philipp Moritz, Robert Nishihara, Stephanie Wang, Alexey Tumanov, Richard Liaw, Eric Liang, Melih Elibol, Zongheng Yang, William Paul, Michael I. Jordan, Ion Stoica
OSDI3
2017 Real-Time Machine Learning: The Missing Pieces
abstract
Machine learning applications are increasingly deployed not only to serve predictions using static models, but also as tightly-integrated components of feedback loops involving dynamic, real-time decision making. These applications pose a new set of requirements, none of which are difficult to achieve in isolation, but the combination of which creates a challenge for existing distributed execution frameworks: computation with millisecond latency at high throughput, adaptive construction of arbitrary task graphs, and execution of heterogeneous kernels over diverse sets of resources. We assert that a new distributed execution framework is needed for such ML applications and propose a candidate approach with a proof-of-concept architecture that achieves a 63x performance improvement over a state-of-the-art execution framework for a representative application.
Robert Nishihara, Philipp Moritz, Stephanie Wang, Alexey Tumanov, William Paul, Johann Schleier-Smith, Richard Liaw, Mehrdad Niknami, Michael I. Jordan, Ion Stoica
HotOS3
2017 Verifying a high-performance crash-safe file system using a tree specification
abstract
DFSCQ is the first file system that (1) provides a precise specification for fsync and fdatasync, which allow applications to achieve high performance and crash safety, and (2) provides a machine-checked proof that its implementation meets this specification. DFSCQ's specification captures the behavior of sophisticated optimizations, including log-bypass writes, and DFSCQ's proof rules out some of the common bugs in file-system implementations despite the complex optimizations.
Haogang Chen 0001, Tej Chajed, Alex Konradi, Stephanie Wang, Atalay Mert Ileri, Adam Chlipala, M. Frans Kaashoek, Nickolai Zeldovich
SOSP4