The school will focus on the theme of Efficient Scientific Software for Heterogeneous Architectures. The complete programme will offer 25 hours of lectures and hands-on exercises, as well as an additional student presentations session, and a special evening lecture.
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Introduction lecture
Scientific and computing challenges in fundamental physics
by Ivica Puljak (University of Split)- Big question and challenges in modern science, with emphasis on fundamental physics
- Connecting great theoretical ideas and modern experiments to test them
- Future challenges in computing: from traditional increase in data throughput, volume and complexity to emerging concepts of quantum computing, machine learning and artificial intelligence
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Track 1: Technologies and Platforms
4 hours of lectures and 4 hours of hands-on exercises
by Andrzej Nowak (TIK)Introduction to efficient computing
- The evolution of computing hardware and what it means in practice
- The seven dimensions of performance
- Controlling and benchmarking your computer and software
- Software that scales with the hardware
- Advanced performance tuning in hardware
Hardware evolution and heterogeneity
- Accelerators, co-processors, heterogeneity
- Memory architectures, hardware caching and NUMA
- Compute devices: CPU, GPU, FPGA, ASIC etc.
- The role of compilers
Data-oriented design
- Hardware vectorization in detail – theory vs. practice
- Software design for vectorization and smooth data flow
- How can compilers and other tools help?
Summary and future technologies overview
- Teaching program summary and wrap-up
- Next-generation memory technologies and interconnect
- Rack-sized data centres and future computing evolution
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Track 2: Parallel and Optimised Scientific Software
4 hours of lectures and 4 hours of hands-on exercises
by Sebastien Ponce (CERN)Writing parallel software
- Amdahl's and Gustafson's laws
- Asynchronous execution
- Finding concurrency, task vs. data parallelism
- Using threading in C++ and Python, comparison with multi-process
- Resource protection and thread safety
- Locks, thread local storage, atomic operations
Modern programming languages for HEP
- Why Python and C++ ?
- Recent evolutions: C++ 11/14/17
- Modern features of C++ related to performance
- Templating versus inheritance, pros and cons of virtual inheritance
- Python 3, and switching from Python 2
Optimizing existing large codebase
- Measuring performance, tools and key indicators
- Improving memory handling
- The nightmare of thread safety
- Code modernization and low level optimizations
- Data structures for efficient computation in modern C++
Practical vectorization
- Measuring vectorization level
- What to expect from vectorization
- Preparing code for vectorization
- Vectorizing techniques in C++: intrinsics, libraries, autovectorization
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Track 3: Programming for Heterogeneous Architectures
4 hours of lectures and 4 hours of hands-on exercises
by Daniel Campora (Nikhef)Scientific computing on heterogeneous architectures
- Introduction to heterogeneous architectures and the performance challenge
- From general to specialized: Hardware accelerators and applications
- Type of workloads ideal for different accelerators
- Trade-offs between multi-core and many-core architectures
- Implications of heterogeneous hardware on the design and architecture of scientific software
- Embarrassingly parallel scientific applications in HPC and CERN
Programming for GPUs
- From SIMD to SPMD, a programming model transition
- Thread and memory organization
- Basic building blocks of a GPU program
- Debugging and profiling a GPU application
Parallel cross-architecture programming
- Data locality, coalesced memory accesses, tiled data processing
- Control flow, synchronization, atomics
- Other standards: SYCL, HIP, OpenCL
- Middleware libraries and cross-architecture compatibility
Design patterns and best practices
- GPU streams, pipelined memory transfers
- Good practices: single precision, branchless, avoid register spilling, convert the problem
- Reusable parallel design patterns with real-life applications
- Under the hood: Warps, masked execution, floating point rounding
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Additional lectures
Student presentations session
Special evening lecture
Future of the Universe and of Humanity
by Ivica Puljak (University of Split)
