2nd Thematic CERN School of Computing

15 Jun 2014, 09:00 → 20 Jun 2014, 23:30 Europe/Zurich

Alberto Pace (CERN), Giuseppe Lo Presti (CERN), Yasemin Hauser (CERN)

t CSC
"future high-throughput scientific computing"

 

Sunday 15 June

14:00 Arrival

20:00 Dinner at Medils

Monday 16 June

Inaugural Scientific Lecture

1 Physics at the LHC run 1

After a short introduction on the standard model of elementary particles, on the LHC and its experiments, I will present an overview of the main physics results from the first run. Now that the LHC is stopped and we are completing the publication of the analyses of the run 1 data, it is a good time to review the results obtained so far. These could not have been obtained without a number of developments and innovations in the areas of software and computing, which will be even more necessary for the next run.

Speaker: Claude Charlot (Ecole Polytechnique (FR))

Slides LHCPhysicsCERNSchool.pdf LHCPhysicsCERNSchool.ppt

11:00 Updates

11:15 Coffee

Efficient Computing

2 Introduction - Lecture 1

In this lecture we start by discussing Moore’s law which has led to an incredible transistor count becoming available for hardware designers. As a result, modern microprocessors have a high level of complexity and an unprecedented level of parallelism that software programmers are asked to exploit. We define the seven dimensions of performance which will be discussed during the week. The first two (pipelining and superscalar execution are discussed here, whereas the others will be discussed in dedicated lectures).

Speaker: Mr Sverre Jarp (CERN)

12:45 Lunch

Efficient Computing

3 Advanced Performance Tuning - Lecture 2

Benchmarking and performance tuning rarely are first-rate activities. However, the importance of both is on the rise following the trends in hardware related to Moore’s Law. In this lecture we will explain advanced aspects of performance benchmarking, monitoring and tuning. The presented methodologies and techniques will be supported by practical information, including compiler examples. Functionality of open-source and commercial tools alike will be demonstrated as an example of common usage of various techniques.

Speaker: Andrzej Nowak (CERN)

15:00 Drinks and fruits

Efficient Computing

4 Advanced Tuning - Exercise 1

Speakers: Andrzej Nowak (CERN), Mr Sverre Jarp (CERN)

5 Advanced Tuning - Exercise 2

Speakers: Andrzej Nowak (CERN), Mr Sverre Jarp (CERN)

17:30 Transportation to Downtown & Guided tour of Split

20:00 Outside Welcome Dinner

Tuesday 17 June

Data Oriented Design

6 Data Oriented Design - Lecture 1

This lecture will explain fundamental principles of data-oriented design. With the re-emergence of vectorization as a key optimization technique, indispensable for the full use of modern computing platforms, data-oriented design drives successful, scalable projects. We will explain how data-intensive problems can map onto implementations in practice, and how advanced hardware can accelerate them.

Speaker: Andrzej Nowak (CERN)

Memory Programming

7 Memory Awareness - Lecture 1

Processor speeds have outperformed the speed of memory which often becomes a bottleneck in modern servers. In this lecture we review the concept of virtual memory and the paging subsystem found in every modern operating system. We discuss the cache hierarchy and go on to look at a relatively new phenomenon in small-scale servers, namely “non-uniform memory access” (NUMA) and how to control it with affinity scheduling. Finally, we discuss briefly memory footprints and a topic that will become “hot” in the next coming years, “energy-efficient” programming.

Speaker: Mr Sverre Jarp (CERN)

11:00 Updates

11:15 Coffee

Efficient Computing

8 Floating Point Programming - Lecture 4

We start by asked ourselves why we need to bother about this topic at all. Hopefully, having convinced ourselves, we then discuss the IEEE-754 standard which is used in all modern microprocessors. We discuss several techniques for keeping floating-point calculations accurate. Math functions, such as exponentials and power functions, are also invoked, since they can be costly in performance and also have a large impact of the accuracy of floating-point calculations.

Speaker: Mr Sverre Jarp (CERN)

12:45 Lunch

13:30 Study Time* and/or Daily Sports Program

16:00 Drinks & fruits

Data Oriented Design

9 Data Oirented Design - Exercise 1

Speaker: Andrzej Nowak (CERN)

Memory Programming

10 Memory programming - Exercise 1

Speaker: Mr Sverre Jarp (CERN)

Efficient Computing

11 Floating Point - Exercise 3

Speaker: Mr Sverre Jarp (CERN)

19:30 Free time

20:00 Dinner at Medils

Wednesday 18 June

Programming for Concurrency

12 Modern and performant C++ - Lecture 1

The ability to design and implement high throughput scientific applications leveraging the features of a modern programming language is crucial. In this lecture we focus on C++ and in particular on its latest standard, C++11. Starting from real life and concrete examples, we review the newly introduced semantics and constructs relevant for achieving top performance parallel implementations. Software design principles allowing to seamlessly accommodate such implementations are discussed. High level tools for measuring software performance are as well introduced.

Speaker: Danilo Piparo (CERN)

13 Expressing parallelism pragmatically - Lecture 2

This lecture focuses on the problem of expressing parallelism adapting existing scientific software and designing future applications. Design principles aiming to the formulation of parallel programs and data processing frameworks are presented. The concept of task oriented parallelism is introduced as well as the difficulties of the related work partitioning. The features are explored which the C++ language and a selection of libraries offer for concurrent programming.

Speaker: Danilo Piparo (CERN)

11:00 Updates

11:15 Coffee

Programming for Concurrency

14 Programming for Concurrency - Exercise 1

Simple exercises not necessarily involving programming are proposed at the beginning to make sure that the main concepts discussed in the lectures have been properly acquired. Real performance driven development of concurrent software then starts, considering small programs and the modification thereof. The power of the new semantics will be illustrated.

Speaker: Danilo Piparo (CERN)

12:45 Lunch

13:30 Sports Afternoon

20:00 Outside Dinner

Thursday 19 June

Programming for Concurrency

15 Resource protection and thread safety - Lecture 3

A fundamental aspect of concurrent programming is the protection of thread unsafe resources. With argumentations relying on concrete use cases, the issue of thread safety and its possible solutions are treated. Designs aiming to avoid contention are characterised, offering veritable patterns applicable also in different disciplines. Different resource protection strategies are evaluated discussing concrete examples.

Speaker: Danilo Piparo (CERN)

16 Programming for Concurrency - Parallelism - Exercise 2

Exercises aiming to better understand the concepts of data and task parallelism are proposed. Simple parallelisation is achieved using different programming models: pure C++11, openMP and TBB. The measurement of software performance is explored. The final exercise is a small project for additional development experience.

Speaker: Danilo Piparo (CERN)

10:30 Updates

10:45 Coffee

Programming for Concurrency

17 Programming for Concurrency - Exercise 3

In these exercises the concepts behind resource protection are put to a good use. The opportunity is offered to design and develop different solutions for thread safety issues. The pre-digested solutions offered by widely known libraries and toolkits are compared. The student is also invited to test her knowledge using different programming languages.

Speaker: Danilo Piparo (CERN)

12:00 Lunch

12:45 Study Time* and/or Daily Sports Program (Group departure:12:45)

16:00 Drinks and fruits

Efficient Computing

18 Putting it all together - Lecture 3

Speaker: Danilo Piparo (CERN)

19 Putting it all together - Exercise 4

Speakers: Andrzej Nowak (CERN), Danilo Piparo (CERN), Mr Sverre Jarp (CERN)

20 Putting it all together - Exercise 5

Speakers: Andrzej Nowak (CERN), Danilo Piparo (CERN), Mr Sverre Jarp (CERN)

19:30 Free time

20:00 Dinner at Medils

Friday 20 June

Acceleration

21 Acceleration, Heterogeneity and Programming for Accelerators - Lecture 1

Affordable and efficient accelerators are becoming a standard data-center offering. However, programming these devices requires a shift to a heterogeneous approach, discussed here, where data access between nodes can be expensive and floating point answers obtained on different hardware can diverge. In particular, we will cover the up- and down-sides of direct, offload and symmetric acceleration. GPU and Many Integrated Core devices will be used as examples.

Speaker: Andrzej Nowak (CERN)

10:00 Self-Evaluation session

11:00 Updates

11:15 Coffee

Presentations by students

22 RefCruncher: A tool for scientists

Speaker: Dr Miguel Rubio-Roy (CNRS)

23 Efficient parallel I/O on multi-core architectures

Speaker: Adrien Devresse (CERN)

Slides efficient_parallel_IO_on_multicore_arch2.odp efficient_parallel_IO_on_multicore_arch2.pdf

24 "Linux containers"

Speaker: Elvin Alin Sindrilaru (CERN)

Slides Elvin_Sindrilaru_Linux_Containers.pdf

25 Data Oriented Design "Generic programming"

Speaker: Johannes Christof de Fine Licht (University of Copenhagen (DK))

Slides tCSC_Johannes_GenericProgramming.pdf tCSC_Johannes_GenericProgramming.ppt

26 Top-k Completion

Speaker: Jonas Kunze (Johannes-Gutenberg-Universitaet Mainz (DE))

Slides tCSC14-split.svg

12:45 Lunch

Acceleration

27 Future Directions & Wrap-up

Speaker: Andrzej Nowak (CERN)

Closing Scientific Lecture (TBD)

28 Closing Scientific Lecture

Speakers: Ivica Puljak (Technical University of Split FESB), Ivica Puljak (University of Split (HR))

Slides Big_questions.pdf Big_questions.ppt

16:00 Drinks and fruits

16:30 Closing Session

17:30 Free time

20:00 Outside Closing Dinner