The Remote Enqueue Operation on Networks of Workstations

Modern networks of workstations connected by Gigabit net works have the ability to run high performance computing applications at a reasonable performance but at a signi cantly lower cost The per formance of these applications is usually dominated by their e ciency of the underlying communication mechanisms However e cient communi cation requires that not only messages themselves are sent fast but also noti cation about message arrival should be fast as well For example a message that has arrived at its destination is worthless until the recipient is alerted to the message arrival In this paper we describe a new operation the remote enqueue atomic operation which can be used in multiprocessors and workstation clus ters This operation atomically inserts a data element in a queue that physically resides in a remote processor s memory This operation can be used for fast noti cation of message arrival and for fast passing of small messages Compared to other software and hardware queueing al ternatives remote enqueue provides high speed at a low implementation cost without compromising protection in a general purpose computing environment