|
Parralel Computing Turorial |
|
|
|
|
Written by Hemanshu Patel
|
|
Sunday, 23 December 2007 |
|
Page 11 of 18
Parallel Programming ModelsOther Models
* Other parallel programming models besides those previously mentioned certainly exist, and will continue to evolve along with the ever changing world of computer hardware and software. Only three of the more common ones are mentioned here.
Hybrid:
* In this model, any two or more parallel programming models are combined.
* Currently, a common example of a hybrid model is the combination of the message passing model (MPI) with either the threads model (POSIX threads) or the shared memory model (OpenMP). This hybrid model lends itself well to the increasingly common hardware environment of networked SMP machines.
* Another common example of a hybrid model is combining data parallel with message passing. As mentioned in the data parallel model section previously, data parallel implementations (F90, HPF) on distributed memory architectures actually use message passing to transmit data between tasks, transparently to the programmer.
Single Program Multiple Data (SPMD):
* SPMD is actually a "high level" programming model that can be built upon any combination of the previously mentioned parallel programming models. SPMD Model
* A single program is executed by all tasks simultaneously.
* At any moment in time, tasks can be executing the same or different instructions within the same program.
* SPMD programs usually have the necessary logic programmed into them to allow different tasks to branch or conditionally execute only those parts of the program they are designed to execute. That is, tasks do not necessarily have to execute the entire program - perhaps only a portion of it.
* All tasks may use different data
Multiple Program Multiple Data (MPMD):
* Like SPMD, MPMD is actually a "high level" programming model that can be built upon any combination of the previously mentioned parallel programming models. MPMD Model
* MPMD applications typically have multiple executable object files (programs). While the application is being run in parallel, each task can be executing the same or different program as other tasks.
* All tasks may use different data
|
|
Last Updated ( Sunday, 23 December 2007 )
|
Technology 