This is not a process. It is the method by which the separate daemons communicate. All processes wishing to read/write some data must acquire the correct semaphore and write to the desired structure.
Of course, this mmap'd memory must be instantiated somewhere. This is handled by the shmem_mgr and nowhere else.
To help visualize the communication of processes, we have created shmem_viewer. It is a simple program that uses a TUI to display bits for the desired shmem_struct.