MVAPICH2 uses CPU affinity to have better performance for single-threaded programs. For multi-threaded programs, however, it may schedule all the threads of a process to run on the same CPU. CPU affinity should be disabled in this case to solve the problem, i.e. set -env
MV2 ENABLE AFFINITY 0.
原来是默认绑定了。。我想当然了,没看手册。。谢谢楼上了