Zoltan hypergraph partitioner backend. More...

#include <parti_zoltan.hpp>

Classes
class	Hypergraph
	internal data class to be used by callback functions More...

Public Member Functions
	PartiZoltan (const Dist::Comm &comm, Index min_elems=1000u, int max_procs=1000)
	Constructor. More...

virtual	~PartiZoltan ()
	virtual destructor

Adjacency::Graph	build_elems_at_rank () const
	Builds and returns the elements-at-rank graph representing the partitioning. More...

bool	execute (const Adjacency::Graph &faces_at_elem, const Index num_parts, const std::vector< Real > &weights)
	Executes the Zoltan partitioner. More...

template<int n_>
bool	execute (const IndexSet< n_ > &faces_at_elem, const Index num_parts, const std::vector< Real > &weights)
	Executes the Zoltan partitioner. More...

int	get_sub_comm_size () const
	Returns the size of the internal sub-communicator. More...

Protected Member Functions
bool	_apply_zoltan ()
	auxiliary function: applies Zoltan onto the hypergraph

bool	_broadcast_coloring (bool zoltan_ok)
	auxiliary function: broadcasts the coloring from the root process

void	_create_hypergraph (const Adjacency::Graph &faces_at_elem, const std::vector< Real > &weights)
	auxiliary function: builds a hypergraph from the adjacency graph

bool	_gather_coloring (const int num_export, const int *export_parts)
	auxiliary function: gathers the partitioned coloring onto the root process

Private Attributes
Adjacency::Coloring	_coloring
	the element coloring More...

const Dist::Comm &	_comm
	our main communicator More...

Hypergraph	_hypergraph
	our hypergraph structure More...

int	_max_procs
	maximum number of MPI processes to use More...

Index	_min_elems
	minimum number of elements per MPI process More...

Index	_num_elems
	the total number of elements More...

Index	_num_parts
	the desired number of partitions More...

Dist::Comm	_zoltan_comm
	a sub-communicator for the partitioner More...

void *	_zz
	zoltan internal data More...

Detailed Description

Zoltan hypergraph partitioner backend.

This class implements a backend for the Zoltan partitioner from the Sandia National Laboratories. This class only makes use for Zoltan's homebrew Hypergraph partitioners and does not use any of its other partitioning methods, although these could be integrated into this class later, if desired/required. This class is used by the Control::Domain::PartiDomainControl class and its functionality can be used by specifying the tag zoltan as a parameter to the –parti-type command line option.

Note that this class is only available if FEAT is configured and linked against the Zoltan third-party library, of course.

Todo:

figure out max_procs/min_elems

allow the user to configure more Zoltan parameters

Author: Peter Zajac

Definition at line 38 of file parti_zoltan.hpp.

Constructor & Destructor Documentation

◆ PartiZoltan()

FEAT::Geometry::PartiZoltan::PartiZoltan	(	const Dist::Comm &	comm,
		Index	min_elems = `1000u`,
		int	max_procs = `1000`
	)

explicit

Constructor.

Parameters

[in] comm A resident reference to the communicator to be used by the partitioner. In a recursive partitioning setting, this has to be the progeny communicator.

Note that this class might create a sub-communicator of comm internally if there are too many ranks in the communicator for the given number of mesh elements or desired number of partitions to improve the computation vs communication trade-off.

Member Function Documentation

◆ build_elems_at_rank()

Adjacency::Graph FEAT::Geometry::PartiZoltan::build_elems_at_rank ( ) const

inline

Builds and returns the elements-at-rank graph representing the partitioning.

Definition at line 145 of file parti_zoltan.hpp.

References _coloring, and FEAT::Adjacency::Coloring::create_partition_graph().

Referenced by FEAT::Control::Domain::PartiDomainControlBase< DomainLevel_ >::_apply_parti_zoltan().

◆ execute() [1/2]

bool FEAT::Geometry::PartiZoltan::execute	(	const Adjacency::Graph &	faces_at_elem,
		const Index	num_parts,
		const std::vector< Real > &	weights
	)

Executes the Zoltan partitioner.

Parameters

[in]	faces_at_elem	A transient reference to the faces-at-element adjacency graph of the mesh that is to be partitioned. The face-dimension of the graph can be chosen freely, but typically in the finite element case this is the vertices-at-element index set of the mesh.
[in]	num_parts	The desired number of partitions to create. Must be > 0, but it does not necessarily need to be equal to the number of processes in the communicator.
[in]	weights	A vector containing the distribution weights for each element. May be empty if all elements are to be weighted equally.

Returns: true, if the partitioning was successful, or false, if some error occurred.

◆ execute() [2/2]

template<int n_>

bool FEAT::Geometry::PartiZoltan::execute	(	const IndexSet< n_ > &	faces_at_elem,
		const Index	num_parts,
		const std::vector< Real > &	weights
	)

inline

Executes the Zoltan partitioner.

Parameters

[in]	faces_at_elem	A transient reference to the faces-at-element index set of the mesh that is to be partitioned. The face-dimension of the index set can be chosen freely, but typically in the finite element case this is the vertices-at-element index set of the mesh.
[in]	num_parts	The desired number of partitions to create. Must be > 0, but it does not necessarily need to be equal to the number of processes in the communicator.
[in]	weights	A vector containing the distribution weights for each element. May be empty if all elements are to be weighted equally.

Returns: true, if the partitioning was successful, or false, if some error occurred.

Definition at line 116 of file parti_zoltan.hpp.

References FEAT::Adjacency::as_is, and execute().

Referenced by FEAT::Control::Domain::PartiDomainControlBase< DomainLevel_ >::_apply_parti_zoltan(), and execute().

◆ get_sub_comm_size()

int FEAT::Geometry::PartiZoltan::get_sub_comm_size ( ) const

inline

Returns the size of the internal sub-communicator.

This only gives useful results after the execute() function has been called.

Definition at line 155 of file parti_zoltan.hpp.

References _zoltan_comm, and FEAT::Dist::Comm::size().

Member Data Documentation

◆ _coloring

Adjacency::Coloring FEAT::Geometry::PartiZoltan::_coloring

private

the element coloring

Definition at line 76 of file parti_zoltan.hpp.

Referenced by build_elems_at_rank().

◆ _comm

const Dist::Comm& FEAT::Geometry::PartiZoltan::_comm

private

our main communicator

Definition at line 62 of file parti_zoltan.hpp.

◆ _hypergraph

Hypergraph FEAT::Geometry::PartiZoltan::_hypergraph

private

our hypergraph structure

Definition at line 74 of file parti_zoltan.hpp.

◆ _max_procs

int FEAT::Geometry::PartiZoltan::_max_procs

private

maximum number of MPI processes to use

Definition at line 66 of file parti_zoltan.hpp.

◆ _min_elems

Index FEAT::Geometry::PartiZoltan::_min_elems

private

minimum number of elements per MPI process

Definition at line 68 of file parti_zoltan.hpp.

◆ _num_elems

Index FEAT::Geometry::PartiZoltan::_num_elems

private

the total number of elements

Definition at line 70 of file parti_zoltan.hpp.

◆ _num_parts

Index FEAT::Geometry::PartiZoltan::_num_parts

private

the desired number of partitions

Definition at line 72 of file parti_zoltan.hpp.

◆ _zoltan_comm

Dist::Comm FEAT::Geometry::PartiZoltan::_zoltan_comm

private

a sub-communicator for the partitioner

Definition at line 64 of file parti_zoltan.hpp.

Referenced by get_sub_comm_size().

◆ _zz

void* FEAT::Geometry::PartiZoltan::_zz

private

zoltan internal data

Definition at line 78 of file parti_zoltan.hpp.

The documentation for this class was generated from the following file:

kernel/geometry/parti_zoltan.hpp

Classes

Public Member Functions

Protected Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ PartiZoltan()

Member Function Documentation

◆ build_elems_at_rank()

◆ execute() [1/2]

◆ execute() [2/2]

◆ get_sub_comm_size()

Member Data Documentation

◆ _coloring

◆ _comm

◆ _hypergraph

◆ _max_procs

◆ _min_elems

◆ _num_elems

◆ _num_parts

◆ _zoltan_comm

◆ _zz