[mpich-devel] MPI_Recv, blocking call concept

Dear all, The blocking call definition from my understanding is something like this: when a process(P0) do a blocking system call, scheduler block the process and assign another process(P1) in order to efficiently use of CPU core. Finally P0 response will be ready and scheduler can map it again on a core. But this is not what happening In MPICH->MPI_Recv function. you call it BLOCKING call, but the process that call this function actually doesn't block, it just continue running on core WAITING for his response. Why you decide to do this? why we have a process waiting on a valuable processing core and burning the power?