This course covers performance engineering approaches on the compute node level. Even application developers who are fluent in OpenMP and MPI often lack a good grasp of how much performance could at best be achieved by their code. This is because parallelism takes us only half the way to good performance. Even worse, slow serial code tends to scale very well, hiding the fact that resources are wasted. This course conveys the required knowledge to develop a thorough understanding of the interactions between software and hardware. This process must start at the core, socket, and node level, where the code gets executed that does the actual computational work. We introduce the basic architectural features and bottlenecks of modern processors and compute nodes. Pipelining, SIMD, superscalarity, caches, memory interfaces, ccNUMA, etc., are covered. A cornerstone of node-level performance analysis is the Roofline model, which is introduced in due detail and applied to various examples from computational science. We also show how simple software tools can be used to acquire knowledge about the system, run code in a reproducible way, and validate hypotheses about resource consumption. Finally, once the architectural requirements of a code are understood and correlated with performance measurements, the potential benefit of code changes can often be predicted, replacing hope-for-the-best optimizations by a scientific process.
This course provides - via lectures, demos, and hands-on labs - scientific training in Computational Science, and in addition, the scientific exchange of the participants among themselves.
Online course Organizer: HLRS, University of Stuttgart, Germany
Jun 27, 2023
Jun 30, 2023
Performance Optimization & Debugging
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Learn more about course curricula and content levels.
Dr. habil. Georg Hager and Dr.-Ing. Jan Eitzinger (NHR@FAU, Uni. Erlangen) Bert Wesarg (ZIH Uni. Dresden) for the tools-day
The agenda can be downloaded here.
Day 4 (Tools Day)
Tools topology & affinity in multicore environments
Microbenchmarking for architectural exploration
Roofline model: basics
Tools: hardware performance counters
Roofline case studies
Optimal use of parallel resources
Extending Roofline: The ECM performance model
Optional: Pattern-based performance engineering
Before the course, the course material and an updated agenda will be available here.
An older version of this course with most of the material (including the audio information) can also be viewed in the online self-study materials.
Register via the button at the top of this page. We encourage you to register to the waiting list if the course is full. Places might become available.
Registration due to June 2, 2023. Late registrations after this date are still possible according to the course capacity, maybe with reduced quality of the service.
Link to the EU and EU-associated (Horizon Europe), and PRACE countries.
Our course fees include coffee breaks (in classroom courses only).
Lucienne Dettki, phone 0711 685 63894, dettki(at)hlrs.de
HLRS is part of the Gauss Centre for Supercomputing (GCS), together with JSC in Jülich and LRZ in Garching near Munich. EuroCC@GCS is the German National Competence Centre (NCC) for High-Performance Computing. HLRS is also a member of the Baden-Württemberg initiative bwHPC.
This course is provided within the framework of the bwHPC training program.
See the training overview and the Supercomputing Academy pages.
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High-Performance Computing Center Stuttgart
Nobelstraße 19, 70569 Stuttgart, Germany
+49 711 685-87209
A member of the Gauss Centre for Supercomputing, HLRS is one of three German national centers for high-performance computing.
HLRS is a central unit of the University of Stuttgart.