Optimization of thread affinity and memory affinity for remote core locking synchronization in multithreaded programs for multicore computer systems

Alexey Paznikov

doi:10.21595/vp.2017.18689

Abstract

This paper proposes the algorithms for optimization of Remote Core Locking (RCL) synchronization method in multithreaded programs. The algorithm of initialization of RCL-locks and the algorithms for threads affinity optimization are developed. The algorithms consider the structures of hierarchical computer systems and non-uniform memory access (NUMA) to minimize execution time of RCL-programs. The experimental results on multi-core computer systems represented in the paper shows the reduction of RCL-programs execution time.

Highlights

Distributed computer systems (CS) [1] are large-scale and include multiple architectures
We proposed the algorithm RCLLockInitNUMA of initialization of Remote Core Locking (RCL)-lock with considering the non-uniform memory access in multi-core NUMA-systems and the algorithm RCLHierarchicalAffinity of sub-optimal thread affinity in hierarchical multi-core computer systems
The algorithm RCLLockInitNUMA increases by 10-20 % at the average the throughput of critical sections of parallel multithreaded programs based on RCL at random access and strided access to the elements of arrays on the NUMA multi-core systems

Summary

Introduction

Distributed computer systems (CS) [1] are large-scale and include multiple architectures. The existing approaches for thread synchronization include locks, lock-free algorithms and concurrent data structures [2] and software transactional memory [3]. The works [14, 15] are devoted to concurrent data structures development (lists and hash tables) based on critical section execution on dedicated processor cores. OPTIMIZATION OF THREAD AFFINITY AND MEMORY AFFINITY FOR REMOTE CORE LOCKING SYNCHRONIZATION IN MULTITHREADED PROGRAMS FOR MULTICORE COMPUTER SYSTEMS. ALEXEY PAZNIKOV time of existing programs thanks to critical path reduction This technique assumes replacement of high-load critical sections in existing multithreading applications to remote functions calls for its execution on dedicated processor cores (Fig. 1). The algorithms consider the hierarchical structure of multi-core CS and non-uniform memory access in NUMA-systems to minimize critical sections execution time

RCL optimization algorithms

Experimental results

Conclusions