legate::ParallelPolicy#

class ParallelPolicy#

A helper class that describes parallelization policies for tasks.

A ParallelPolicy consists of knobs to control the parallelization policy for tasks in a given scope. To change the parallelization policy of the scope, a new Scope must be created with a ParallelPolicy. Currently, the ParallelPolicy class provides the following parameters:

streaming() (default: false): When the streaming() is true in a scope, the runtime executes the tasks in a streaming fashion. For example, if there are two tasks T1 and T2 in the scope, the normal execution would run all parallel instances of T1 before it would move on to T2’s, whereas the streaming execution would alternative between T1 and T2, launching a subset of parallel instances at a time that would fit to the memory. The granularity of tasks can be configured by the overdecompose_factor() (see below), and if the overdecompose_factor() is 1, no streaming would happen even if the streaming() is true.
overdecompose_factor() (default: 1): When the value is greater than 1, the auto-partitioner will over-decompose the stores when partitioning them; by default, the auto-partitioner creates N chunks in a store partition when there are N processors, but if the overdecompose_factor() is k in the scope, it would create kN chunks in the partition.

Public Functions

ParallelPolicy &with_streaming(bool streaming)#

Sets the flag that indicates whether tasks in a given scope should be streamed.

Parameters:: streaming – A boolean value to set to the streaming flag.

ParallelPolicy &with_overdecompose_factor( std::uint32_t overdecompose_factor )#

Sets the over-decomposing factor.