Dynamic Assignment

• Dynamic assignment comes with its own overhead
  • Now you need to maintain a shared count of the number of available tasks
  • The update of this variable must be protected by a lock
  • Need to be careful so that this lock contention does not outweigh the benefits of dynamic decomposition
• More complicated applications where a task may not just operate on an index range, but could manipulate a subtree or a complex data structure
  • Normally a dynamic task queue is maintained where each task is probably a pointer to the data
  • The task queue gets populated as new tasks are discovered

Decomposition Types

• Decomposition by data
  • The most commonly found decomposition technique
  • The data set is partitioned into several subsets and each subset is assigned to a process
  • The type of computation may or may not be identical on each subset
  • Very easy to program and manage
• Computational decomposition
  • Not so popular: Tricky to program and manage
  • All processes operate on the same data, but probably carry out different kinds of computation
  • More common in systolic arrays, pipelined graphics processor units (GPUs) etc.