Though shared virtual memory (SVM) systems promise low cost solutions for high performance computing, they suffer from long memory latencies. These latencies are usually caused by repetitive invalidations on shared data. Since shared data are accessed through synchronizations and the patterns by which threads synchronizes are repetitive, a prefetching scheme based on such repetitiveness would reduce memory latencies. Based on this observation, we propose a prefetching technique which predicts future access behavior by analyzing access history per synchronization variable. Our technique was evaluated on an 8-node SVM system using the SPLASH-2 benchmark. The results show that our technique could achieve 34% - 45% reduction in memory access latencies.