Research

I spent a decade in computer architecture research before moving into industry. My work focused on GPUs, memory systems, and task parallelism.

Research Interests

Computer ArchitectureGPUsMemory SystemsTask-Based ParallelismRuntime SystemsPerformance ModelingMemory ConsistencyScheduling & Runtime OptimizationsDigital Twins5G/6G Simulation

Industry Research

Ericsson

2019–2023

At Ericsson, I led the development of 5G digital twins using NVIDIA Omniverse. We built simulation tools for radio wave propagation in realistic 3D environments — enabling real-time prediction of how antennas behave in different conditions.

This work was:

  • Featured in NVIDIA's GTC Keynote (twice)
  • Presented directly to Jensen Huang
  • Covered by NVIDIA Blog, Ericsson Blog, and industry press

I worked closely with NVIDIA's Omniverse team as an early adopter, contributing to the platform's development for industrial simulation use cases.


Academic Research

Uppsala University

2013–2018

I completed my PhD with the Uppsala Architecture Research Team (UART), one of Europe's leading computer architecture groups. My research explored how task-based parallel programsinteract with memory systems, and how to optimize scheduling for better performance and energy efficiency.

I also developed tools for analyzing graphical workloads on tile-based GPUs — work that was recognized with multiple best paper awards.

Advisors: David Black-Schaffer and Erik Hagersten

FaMAF logo

FaMAF, Universidad Nacional de Córdoba

2008–2013

As a member of the GPGPU Computing Group, I conducted interdisciplinary research on GPGPU computing tailored to physical simulations using CUDA.

My key achievement was developing the world's first GPU-powered Parallel Adaptive Mesh Refinement (AMR) framework for large-scale physical simulations. This work was presented at several international conferences.

Advisors: Prof. Oscar Reula (PhD) and Prof. Nicolás Wolovick (PhD)


Academic Leadership & Teaching

Throughout my academic career, I contributed to education at both undergraduate and graduate levels, designing courses and mentoring students in computer architecture and systems programming.

  • Main Instructor / Course DesignerUppsala University (2015–2018)
    • Advanced Computer Architecture (PhD/MSc)
    • Operating Systems II (MSc)
  • Teaching AssistantUppsala University & Universidad Nacional de Córdoba (2010–2018)
    • Computer Architecture
    • Operating Systems
    • Parallel Programming
    • Introduction to Computing

Research Software & Tools

I developed several tools for analyzing memory behavior and performance in parallel and graphical workloads.

GLTraceSim

A trace-driven simulator for analyzing graphical workloads on tile-based GPUs. Enables detailed memory and performance analysis of graphics rendering pipelines.

Tech: C++, Python, OpenGL

TaskInsight

A framework for understanding how task scheduling decisions affect memory behavior and application performance in task-based parallel programs.

Tech: C++, Intel PIN, OmpSs

StatTask

A statistical tool for reuse distance analysis in task-based applications, enabling cache performance prediction without cycle-accurate simulation.

Tech: C++, Python, Statistical Modeling


Theses

PhD Thesis (2018)

Understanding Task Parallelism: Providing Insight about Scheduling, Memory, and Performance for CPUs and Graphics

Uppsala University

Licentiate Thesis (2017)

Modeling the Interactions Between Tasks and the Memory System

Uppsala University

MSc Thesis (2013)

A GPU-powered Parallel Adaptive Mesh Refinement Framework for Large-Scale Physical Simulations

Universidad Nacional de Córdoba — Advisors: Prof. Oscar Reula, Prof. Nicolás Wolovick


Selected Publications

Awards

PaperVenueYearAward
Tail-PASS: Resource-based Cache Management for Tiled Graphics Rendering HardwareIEEE ISPA2018Best Paper Award
Behind the Scenes: Memory Analysis of Graphical Workloads on Tile-based GPUsIEEE ISPASS2018Best Paper Award
Understanding the Interplay Between Task Scheduling, Memory and PerformanceACM SPLASH-SRC2017Best Paper Award
How Does Memory Affect the Performance of Tasks?ISC High Performance2017Best Poster Award
Rapid Performance Prediction for Out-of-Order CoresIEEE IPDPS2016Best Poster Award
StatTask: Reuse Distance Analysis for Task-Based ApplicationsRAPIDO @ HiPEAC2015Best Paper Award

Journal Articles

  • Sampled Simulation of Task-Based Programs
    T Grass, TE Carlson, A Rico, G Ceballos, et al.
    IEEE Transactions on Computers, 2018
  • Analyzing Performance Variation of Task Schedulers with TaskInsight
    G Ceballos, T Grass, A Hugo, D Black-Schaffer
    Parallel Computing, 2018
  • Exploring Scheduling Effects on Task Performance with TaskInsight
    G Ceballos, A Hugo, E Hagersten, D Black-Schaffer
    Supercomputing Frontiers and Innovations, 2017

Conference Papers

  • Tail-PASS: Resource-based Cache Management for Tiled Graphics Rendering HardwareIEEE ISPA, 2018
  • Behind the Scenes: Memory Analysis of Graphical Workloads on Tile-based GPUsIEEE ISPASS, 2018
  • TaskInsight: Understanding Task Schedules Effects on Memory and PerformancePMAM @ HPCA, 2017
  • Analyzing Graphics Workloads on Tile-Based GPUsIEEE IISWC, 2017
  • Formalizing Data Locality in Task Parallel ApplicationsICA3PP, 2016
  • StatTask: Reuse Distance Analysis for Task-Based ApplicationsRAPIDO @ HiPEAC, 2015

Academic Profiles


Service to the Research Community

  • Journal ReviewerIEEE Transactions on Parallel and Distributed Systems (TPDS), Cluster Computing
  • Program CommitteeRAPIDO Workshop @ HiPEAC
  • Industry JudgingNVIDIA Omniverse Developer Contest

Honors

  • Heidelberg Laureate Forum (2018)Selected among 200 participants worldwide
  • Best GPA in Computer Science (2013)Universidad Nacional de Córdoba
  • Google Student Ambassador (2012)Universidad Nacional de Córdoba