Exploiting Pipelined Executions in OpenMP

This paper proposes a set of extensions to the OpenMP programming model to express point–to–point synchronization schemes. This is accomplished by defining, in the form of directives, precedence relations among the tasks that are originated from OpenMP work–sharing constructs. The proposal is based on the definition of a name space that identifies the work parceled out by these work–sharing constructs. Then the programmer defines the precedence relations using this name space. This relieves the programmer from the burden of defining complex synchronization data structures and the insertion of explicit synchronization actions in the program that make the program difficult to understand and maintain. The paper briefly describes the main aspects of the runtime implementation required to support precedences relations in OpenMP. The paper focuses on the evaluation of the proposal through its use two benchmarks: NAS LU and ASCI Seep3d.