Tasks and interactions are two important components of parallel computing. Here are some of their characteristics:
Characteristics of Tasks:
1. Independence: Each task should be independent of other tasks, meaning that the execution of one task should not depend on the result of another task.
2. Granularity: Tasks should be of an appropriate size that can be executed efficiently in parallel. Tasks that are too small may lead to overheads due to communication and synchronization, while tasks that are too large may lead to load imbalance.
3. Homogeneity: Tasks should be homogeneous in terms of computation and communication requirements to avoid load imbalance and communication bottlenecks.
4. Scalability: Tasks should be scalable to handle large datasets and an increasing number of processors.
5. Locality: Tasks should be assigned to processors in such a way that the communication and data access are optimized to minimize the communication overhead.
Characteristics of Interactions:
1. Synchronization: Interactions between tasks often require synchronization to ensure that tasks do not execute concurrently and cause inconsistencies in the results.
2. Communication: Interactions between tasks require communication, which can be a significant overhead in parallel computing. Communication should be minimized and optimized to avoid bottlenecks.
3. Topology: The topology of the interconnection network between processors can affect the performance of the parallel algorithm. The network should be optimized to minimize communication latency and bandwidth requirements
4. Data Movement: The movement of data between tasks can be a significant overhead in parallel computing. Data should be moved efficiently to minimize communication overhead.
5. Load Balancing: The interactions between tasks should be balanced to ensure that each processor has a similar workload, and that the execution time is minimized.
Overall, designing an efficient parallel algorithm requires careful consideration of the characteristics of tasks and interactions. The key is to optimize the balance between computation, communication, and synchronization to achieve high-performance parallel computing.