Parallel Programming: for Multicore and Cluster Systems- P43 docx

... F 00  ·  x (k) R x (k) B  +ω  b 1 b 2  . For a parallel implementation the component form of this system is used. On the other hand, for the convergence results the matrix form and the iteration matrix have ... R n R ×n R , D B ∈ R n B ×n B , E ∈ R n B ×n R , and F ∈ R n R ×n B . The submatrices D R and D B are diagonal matrices and the submatrices E and F are sparse band...

Ngày tải lên: 03/07/2014, 16:21

... of A and the value chosen for the relaxation parameter ω. For example the following property holds: If A is symmetric and positive definite and ω ∈ (0, 2), then the SOR method converges for every ... elements a ij 408 7 Algorithms for Systems of Linear Equations Fig. 7.14 Program fragment in C notation and using MPI operations for a parallel Gauss–Seidel iteration for a d...

Ngày tải lên: 03/07/2014, 22:20

... used for distributed address space. The fork–join concept is, for example, used in OpenMP for the creation of threads executing a parallel loop, see Sect. 6.3 for more details. The spawn and exit ... t1 and t2 are temporary array variables.  More information on parallel loops and their execution as well as on transforma- tions to improve parallel execution can be found in...

Ngày tải lên: 03/07/2014, 16:20

... the case for point-to-point operations. The main reason for this is to avoid a large number of additional MPI functions. For the same rea- son, only the standard modus is supported for collective ... array aout and the corresponding process ranks are stored in array ind. For the collection of the information based on value pairs, a data structure is defined for the elements of ar...

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... of the p processes and therefore lies between 0 and p −1. For a correct execution, each participating process must provide for each other process data blocks of the same size and must also receive ... useful for the implementation of task -parallel programs and are the basis for the communication mechanism of MPI. In many situations, it is useful to partition the processes ex...

Ngày tải lên: 03/07/2014, 16:21

... use a different order for locking the mutex variables. This can be seen for two threads T 1 and T 2 and two mutex variables ma and mb as follows: • thread T 1 first locks ma and then mb; • thread ... priorities and the scheduling strategies used, see Sect. 6.1.9 for more information. The order in which waiting threads become owner of a mutex variable is not defined in the Pthrea...

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... call removes the most recently added handler from the cleanup stack. For execute=0, this handler will be executed when it is removed. For execute=0, this handler will be removed without execution. ... cancelled while waiting for the condition variable ps->cond. In this case, the thread first becomes the owner of the mutex variable before termination. Therefore, a cleanup handler is u...

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... effort which is needed for banded matrices with a dense band of semi-bandwidth N. In the following, we consider the method of cyclic reduction for banded matrices, which preserves the sparse banded ... Illustration of the parallel algorithm for the cyclic reduction for n = 8 equations and p = 2 processors. Each of the processors is responsible for q = 4 equations; we have Q = 2....

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... be performed in three time steps. 4.2 Performance Metrics for Parallel Programs 165 4.2.2 Scalability of Parallel Programs The scalability of a parallel program captures the performance behavior for ... cannot be implemented faster and the time Θ(p) results. 4.2 Performance Metrics for Parallel Programs 163 new sequential algorithm performs p times more steps than the paralle...

Ngày tải lên: 03/07/2014, 22:20

... 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, ... 2 Compute the resulting MIPS rate for program X. Exercise 4.3 There is a SPEC benchmark suite MPI2007 for evaluating the MPI performance of parallel systems for floating-poin...

Ngày tải lên: 03/07/2014, 22:20