Hi~ 

    when you run a program with multi-threads.(For instance ,you just type "mpiexec -n 4 ./app" to run an app with four threads.) ,obviously the processor manager will fork several processes to execute the app.What I am wondering is the MPICH2 support processor affinity by default? Does  the MPI process manager(MPICH2 hydra) will bind each forked process to a cpu automatically or just do nothing after forking the processes and waithing for  the os to dispatch this?

     I am appreciate for any reply~Thanks in advance~

Best~