Application of Multi-core Architecture to the MPDRoot Package for the Task ToF Events Reconstruction

摘要

In this article, we propose an approach that allows acceleration of the Time-of-Flight (ToF) event reconstruction algorithm implementation, which is a part of the Multi Purpose Detector (MPD) Root application. Work on the algorithm was carried out in several stages: the program was assembled on the target devices (Intel Xeon E5-2690v3 and E5-2695 v2); Profiling via Valgrind was performed; We selected a code snippet whose execution takes the longest time; Several algorithms for parallelizing code were investigated and the optimal strategy of code enhancement for the equipment in question was implemented. Modification of the selected code fragment was carried out using the OpenMP standard. It is widely used in scientific applications, including the reconstruction of events in the PANDA experiment, and has proven to be useful for work in Multi-Core architecture. The standard is supported by the GCC compiler used to build the MpdRoot framework, which makes it possible to integrate this technology into a fragment of the MpdRoot package without changing the structure or build options of the framework. Due to our optimizations, the algorithm was accelerated on Multi-Core architectures at hand. Paper depicts the direct dependence of the accelerated fragment execution time to the amount of given cores for a given amount of input data. Tests were conducted on the nodes of the heterogeneous cluster JINR "HybriLIT" and cloud node Windows Azure NC12. The paper analyzes the possibilities of optimizing the code for Intel Xeon Phi coprocessors and the problems that we encountered while trying to implement these optimizations.