Parallel Programming: for Multicore and Cluster Systems- P36 ppt

Ngày tải lên: 03/07/2014, 22:20

... reduction oper- ation performed in parallel by the threads of a team. For this kind of calculation OpenMP provides the reduction clause, which can be used for parallel, sections, and for constructs. The ... The second parallel loop performs the matrix multiplication in a nested for loop. The for construct applies to the first for loop with iteration variable row and, thus,...

Ngày tải lên: 03/07/2014, 16:21

... separate thread available for execution. Therefore, the application program must apply parallel pro- gramming techniques to get performance improvements for SMT processors. 2.4.2 MulticoreProcessors According ... be used for the transmission and the switching strategy which determines whether and how mes- sages are cut into pieces, how a routing path is assigned to a message, and...

Ngày tải lên: 03/07/2014, 16:20

... Pthreads and Sect. 6.2.3 for Java threads. 114 3 Parallel Programming Models j, j + p, , j + p · ( n/p−1 ) for j ≤ n mod p and j, j + p, , j + p · ( n/p−2 ) for n mod p < j ≤ p. For the ... partitioning. In a parallel program, the processors perform computations only on their part of the data. Data distributions can be used for parallel programs for distributed as...

Ngày tải lên: 03/07/2014, 16:20

... are no dependencies and the loops over i and j can be exchanged. For a parallel implementation, the row- and column-oriented representations of matrix A give rise to different parallel imple- mentation ... b, and c for the program given in Fig. 3.10. For a row-oriented cyclic distribution, each processor P k , k = 1, , p,stores the rows a i of matrix A with i = k + p ·(l − 1...

Ngày tải lên: 03/07/2014, 16:20

... Language bindings for C, C++, Fortran-77, and Fortran-95 are sup- ported. In the following, we concentrate on the interface for C and describe the most important features. For a detailed description, ... product and a matrix–vector multiplication and derive the formula for the running time on a mesh topology. Exercise 4.14 Develop a runtime function to capture the execution ti...

Ngày tải lên: 03/07/2014, 16:21

... communication partners in the form source/dest are given in this order. For example, for the process with rank=5,itiscoords[1]=1, and there- fore source=9 (lower neighbor in dimension 0) and dest=1 (upper ... and source for each pro- cess. These are then used as parameters for MPI Sendrecv(). The following diagram illustrates the exchange. For each process, its rank, its Carte...

Ngày tải lên: 03/07/2014, 16:21

... a.swapBalance(b) and locks the mutex variable of object a; • time T 2 : thread A calls getBalance() for object a and executes this function; • time T 2 : thread B calls b.swapBalance(a) and locks the ... pthread - cond wait() and pthread cond signal() for condition variables in Pthreads, see Sect. 6.1.3, p. 270. The methods wait() and notify() are imple- mented using an implicit...

Ngày tải lên: 03/07/2014, 16:21

... wait() and notify(). This is shown in Fig. 6.35 for a class Barrier, see also [129]. The Barrier class contains a constructor which initializes a Barrier object with the number of threads to wait for ... shown in Fig. 6.39 can be used for the synchro- nization of producer and consumer threads. A similar mechanism has already been implemented in Fig. 6.32 by using wait() and notify...

Ngày tải lên: 03/07/2014, 16:21

Ngày tải lên: 03/07/2014, 22:20