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- /*! \page ModularizedScheduler Modularized Scheduler
- \section Introduction
- Scheduler are a tree-like structure of homogeneous nodes that each
- provides push and pop primitives. Each node may have one father by
- context, specially worker nodes as they are shared between all contexts.
- Tasks make a top bottom traversal of tree.
- A push call on a node make either a recursive call on one of its
- childs or make the task stored in the node and made available to a
- pop, in this case that node should call starpu_sched_node_available to wake workers
- up. Push must be called on a child, and only if this child can execute
- the task.
- A pop call on a node can either return a locally stored task or perform
- a recursive call on its father in its current context. Only workers
- should call pop.
- \section Initialization
- Scheduler node are created with the starpu_sched_node_foo_create() functions
- and then must be assembled using them starpu_sched_node::add_child and
- starpu_sched_node::remove_child functions.
- A father can be set to allow him to be reachable by a starpu_sched_node::pop_task
- call.
- Underlyings workers are memoized in starpu_sched_node::workers. Hence the
- function starpu_sched_tree_update_workers should be called when the scheduler is
- finished, or modified.
- \section AddingAndRemovingWorkers Adding and removing workers
- The hypervisor can balance load between contexts by adding or removing workers from a scheduler.
- \section Push
- All scheduler node must define a starpu_sched_node::push_task
- function. The caller ensure that the node can actually execute the task.
- \section Pop
- starpu_sched_node::push_task should either return a local task or
- perform a recursive call on
- starpu_sched_node::fathers[sched_ctx_id], or \c NULL if its a root
- node.
- \section WorkersAndCombinedWorkers Workers and Combined workers
- Leafs are either a worker node that is bind to a starpu workers or a
- combined worker node that is bind to several worker nodes.
- Pushing a task on a combined worker node will in fact push a copy of
- that task on each worker node of the combined worker.
- A push call simply enqueue task in worker queue, no sort is performed
- here.
- If a worker call pop and get a parallel task, it will execute it with the
- combined worker it belong to.
- */
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