For the second time this year, CERN's programmers had the opportunity to participate in a multithreading and parallelism workshop organized jointly by CERN's openlab and Intel. The event took place on 4–5 October and attracted nearly 50 participants.
Two experienced instructors from Intel, Herbert Cornelius and Hans-Joachim Plum, presented classical parallelism theory and practice; described modern mainstream parallel programming techniques such as pthreads, OpenMP and Threading Building Blocks; and warned about common coding pitfalls. The tutors also provided details about upcoming processors, and answered questions during a Q&A session.
On the first day, which consistedentirely of lectures, three members of CERN gave presentations. Sverre Jarp spoke about the challenges that high energy physics software will face in the era of multicore systems; Fons Rademakers described the multithreading efforts in ROOT; and Eric McIntosh recalled his experience with OpenMP in Fortran in the field of computer tomography.
In the hands-on labs on day two, the participants were given assignments relating to the material presented the previous day. Some of Intel's threading products, such as VTune and Thread Checker, were demonstrated in both Linux and Microsoft Windows. The attendees were given the opportunity to use these and other tools to locate bottlenecks and fine-tune the multithreaded exercise&nbso;applications.
A survey conducted after the workshop revealed that all of the respondents had had their expectations fulfilled, and more than 90% said that they would recommend the course to other people. Participants also made several useful suggestions, such as the idea of conducting a survey of the proficiency level and background of participants before the workshop. The comments gathered will help improve future classes and fine-tune the course programme to the audience.
Since the number of subscribers was again much higher than the number of places available, another event will be held next year. A multithreading workshop is planned for spring 2008, and it will focus more on CERN-specific topics with CERN presenters leading the event.
In addition, openlab is considering organizing a workshop on performance monitoring. It would revolve around such topics as the current state of the x86 architecture, performance monitoring in general, and specific tools such as pfmon and VTune. The class is initially planned to take place in January 2008; more details will follow in the coming months.