implementation of engine using MPI More...

Inheritance diagram for rabit::engine::MPIEngine:

Public Member Functions
void	Allgather (void *sendrecvbuf_, size_t total_size, size_t slice_begin, size_t slice_end, size_t size_prev_slice) override
	Allgather function, each node have a segment of data in the ring of sendrecvbuf, the data provided by current node k is [slice_begin, slice_end), the next node's segment must start with slice_end after the call of Allgather, sendrecvbuf_ contains all the contents including all segments use a ring based algorithm.

void	Allreduce (void sendrecvbuf_, size_t type_nbytes, size_t count, ReduceFunction reducer, PreprocFunction prepare_fun, void prepare_arg) override
	performs in-place Allreduce, on sendrecvbuf this function is NOT thread-safe

int	GetRingPrevRank (void) const override
	gets rank of previous node in ring topology

void	Broadcast (void *sendrecvbuf_, size_t size, int root) override
	broadcasts data from root to every other node

virtual void	InitAfterException (void)

virtual int	LoadCheckPoint (Serializable global_model, Serializable local_model=NULL)

virtual void	CheckPoint (const Serializable global_model, const Serializable local_model=NULL)

virtual void	LazyCheckPoint (const Serializable *global_model)

virtual int	VersionNumber (void) const

virtual int	GetRank (void) const
	get rank of current node

virtual int	GetWorldSize (void) const
	get total number of

virtual bool	IsDistributed (void) const
	whether it is distributed

virtual std::string	GetHost (void) const
	get the host name of current node

virtual void	TrackerPrint (const std::string &msg)
	prints the msg in the tracker, this function can be used to communicate progress information to the user who monitors the tracker

Public Member Functions inherited from rabit::engine::IEngine
	~IEngine ()=default
	virtual destructor

virtual int	LoadCheckPoint ()=0

virtual void	CheckPoint ()=0
	Increase internal version number. Deprecated.

Additional Inherited Members
Public Types inherited from rabit::engine::IEngine
typedef void()	PreprocFunction(void *arg)
	Preprocessing function, that is called before AllReduce, used to prepare the data used by AllReduce.

typedef void()	ReduceFunction(const void src, void dst, int count, const MPI::Datatype &dtype)
	reduce function, the same form of MPI reduce function is used, to be compatible with MPI interface In all the functions, the memory is ensured to aligned to 64-bit which means it is OK to cast src,dst to double* int* etc

Detailed Description

implementation of engine using MPI

Member Function Documentation

◆ Allgather()

void rabit::engine::MPIEngine::Allgather	(	void *	sendrecvbuf,
		size_t	total_size,
		size_t	slice_begin,
		size_t	slice_end,
		size_t	size_prev_slice
	)

inlineoverridevirtual

Allgather function, each node have a segment of data in the ring of sendrecvbuf, the data provided by current node k is [slice_begin, slice_end), the next node's segment must start with slice_end after the call of Allgather, sendrecvbuf_ contains all the contents including all segments use a ring based algorithm.

Parameters

sendrecvbuf_	buffer for both sending and receiving data, it is a ring conceptually
total_size	total size of data to be gathered
slice_begin	beginning of the current slice
slice_end	end of the current slice
size_prev_slice	size of the previous slice i.e. slice of node (rank - 1) % world_size

Implements rabit::engine::IEngine.

◆ Allreduce()

void rabit::engine::MPIEngine::Allreduce	(	void *	sendrecvbuf_,
		size_t	type_nbytes,
		size_t	count,
		ReduceFunction	reducer,
		PreprocFunction	prepare_fun,
		void *	prepare_arg
	)

inlineoverridevirtual

performs in-place Allreduce, on sendrecvbuf this function is NOT thread-safe

Parameters

sendrecvbuf_	buffer for both sending and receiving data
type_nbytes	the number of bytes the type has
count	number of elements to be reduced
reducer	reduce function
prepare_func	Lazy preprocessing function, if it is not NULL, prepare_fun(prepare_arg) will be called by the function before performing Allreduce in order to initialize the data in sendrecvbuf. If the result of Allreduce can be recovered directly, then prepare_func will NOT be called
prepare_arg	argument used to pass into the lazy preprocessing function

Implements rabit::engine::IEngine.

◆ Broadcast()

void rabit::engine::MPIEngine::Broadcast	(	void *	sendrecvbuf_,
		size_t	size,
		int	root
	)

inlineoverridevirtual

broadcasts data from root to every other node

Parameters

sendrecvbuf_	buffer for both sending and receiving data
size	the size of the data to be broadcasted
root	the root worker id to broadcast the data

Implements rabit::engine::IEngine.

◆ GetHost()

virtual std::string rabit::engine::MPIEngine::GetHost ( void ) const

inlinevirtual

get the host name of current node

Implements rabit::engine::IEngine.

◆ GetRank()

virtual int rabit::engine::MPIEngine::GetRank ( void ) const

inlinevirtual

get rank of current node

Implements rabit::engine::IEngine.

◆ GetRingPrevRank()

int rabit::engine::MPIEngine::GetRingPrevRank ( void ) const

inlineoverridevirtual

gets rank of previous node in ring topology

Implements rabit::engine::IEngine.

◆ GetWorldSize()

virtual int rabit::engine::MPIEngine::GetWorldSize ( void ) const

inlinevirtual

get total number of

Implements rabit::engine::IEngine.

◆ IsDistributed()

virtual bool rabit::engine::MPIEngine::IsDistributed ( void ) const

inlinevirtual

whether it is distributed

Implements rabit::engine::IEngine.

◆ TrackerPrint()

virtual void rabit::engine::MPIEngine::TrackerPrint ( const std::string & msg )

inlinevirtual

prints the msg in the tracker, this function can be used to communicate progress information to the user who monitors the tracker

Parameters

msg	message to be printed in the tracker

Implements rabit::engine::IEngine.

◆ VersionNumber()

virtual int rabit::engine::MPIEngine::VersionNumber ( void ) const

inlinevirtual

Returns: version number of the current stored model, which means how many calls to CheckPoint we made so far

See also: LoadCheckPoint, CheckPoint

Implements rabit::engine::IEngine.

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

External/xgboost/rabit/src/engine_mpi.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ Allgather()

◆ Allreduce()

◆ Broadcast()

◆ GetHost()

◆ GetRank()

◆ GetRingPrevRank()

◆ GetWorldSize()

◆ IsDistributed()

◆ TrackerPrint()

◆ VersionNumber()