/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
* (C) 2010 by Argonne National Laboratory.
* See COPYRIGHT in top-level directory.
*/
#include "mpiimpl.h"
/*
=== BEGIN_MPI_T_CVAR_INFO_BLOCK ===
cvars:
- name : MPIR_CVAR_IALLTOALL_INTRA_ALGORITHM
category : COLLECTIVE
type : string
default : auto
class : device
verbosity : MPI_T_VERBOSITY_USER_BASIC
scope : MPI_T_SCOPE_ALL_EQ
description : |-
Variable to select ialltoall algorithm
auto - Internal algorithm selection
brucks - Force brucks algorithm
inplace - Force inplace algorithm
pairwise - Force pairwise algorithm
permuted_sendrecv - Force permuted sendrecv algorithm
- name : MPIR_CVAR_IALLTOALL_INTER_ALGORITHM
category : COLLECTIVE
type : string
default : auto
class : device
verbosity : MPI_T_VERBOSITY_USER_BASIC
scope : MPI_T_SCOPE_ALL_EQ
description : |-
Variable to select ialltoall algorithm
auto - Internal algorithm selection
pairwise_exchange - Force pairwise exchange algorithm
- name : MPIR_CVAR_IALLTOALL_DEVICE_COLLECTIVE
category : COLLECTIVE
type : boolean
default : true
class : device
verbosity : MPI_T_VERBOSITY_USER_BASIC
scope : MPI_T_SCOPE_ALL_EQ
description : >-
If set to true, MPI_Ialltoall will allow the device to override the
MPIR-level collective algorithms. The device still has the
option to call the MPIR-level algorithms manually.
If set to false, the device-level ialltoall function will not be
called.
=== END_MPI_T_CVAR_INFO_BLOCK ===
*/
/* -- Begin Profiling Symbol Block for routine MPI_Ialltoall */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Ialltoall = PMPI_Ialltoall
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Ialltoall MPI_Ialltoall
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Ialltoall as PMPI_Ialltoall
#elif defined(HAVE_WEAK_ATTRIBUTE)
int MPI_Ialltoall(const void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf,
int recvcount, MPI_Datatype recvtype, MPI_Comm comm, MPI_Request * request)
__attribute__ ((weak, alias("PMPI_Ialltoall")));
#endif
/* -- End Profiling Symbol Block */
/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
the MPI routines */
#ifndef MPICH_MPI_FROM_PMPI
#undef MPI_Ialltoall
#define MPI_Ialltoall PMPI_Ialltoall
/* This is the machine-independent implementation of alltoall. The algorithm is:
Algorithm: MPI_Alltoall
We use four algorithms for alltoall. For short messages and
(comm_size >= 8), we use the algorithm by Jehoshua Bruck et al,
IEEE TPDS, Nov. 1997. It is a store-and-forward algorithm that
takes lgp steps. Because of the extra communication, the bandwidth
requirement is (n/2).lgp.beta.
Cost = lgp.alpha + (n/2).lgp.beta
where n is the total amount of data a process needs to send to all
other processes.
For medium size messages and (short messages for comm_size < 8), we
use an algorithm that posts all irecvs and isends and then does a
waitall. We scatter the order of sources and destinations among the
processes, so that all processes don't try to send/recv to/from the
same process at the same time.
*** Modification: We post only a small number of isends and irecvs
at a time and wait on them as suggested by Tony Ladd. ***
*** See comments below about an additional modification that
we may want to consider ***
For long messages and power-of-two number of processes, we use a
pairwise exchange algorithm, which takes p-1 steps. We
calculate the pairs by using an exclusive-or algorithm:
for (i=1; i<comm_size; i++)
dest = rank ^ i;
This algorithm doesn't work if the number of processes is not a power of
two. For a non-power-of-two number of processes, we use an
algorithm in which, in step i, each process receives from (rank-i)
and sends to (rank+i).
Cost = (p-1).alpha + n.beta
where n is the total amount of data a process needs to send to all
other processes.
Possible improvements:
End Algorithm: MPI_Alltoall
*/
#undef FUNCNAME
#define FUNCNAME MPIR_Ialltoall_sched_intra_auto
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ialltoall_sched_intra_auto(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
void *recvbuf, int recvcount, MPI_Datatype recvtype,
MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
int mpi_errno = MPI_SUCCESS;
int nbytes, comm_size, sendtype_size;
comm_size = comm_ptr->local_size;
MPIR_Datatype_get_size_macro(sendtype, sendtype_size);
nbytes = sendtype_size * sendcount;
if (sendbuf == MPI_IN_PLACE) {
mpi_errno =
MPIR_Ialltoall_sched_intra_inplace(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, comm_ptr, s);
} else if ((nbytes <= MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE) && (comm_size >= 8)) {
mpi_errno =
MPIR_Ialltoall_sched_intra_brucks(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, comm_ptr, s);
} else if (nbytes <= MPIR_CVAR_ALLTOALL_MEDIUM_MSG_SIZE) {
mpi_errno =
MPIR_Ialltoall_sched_intra_permuted_sendrecv(sendbuf, sendcount, sendtype, recvbuf,
recvcount, recvtype, comm_ptr, s);
} else {
mpi_errno =
MPIR_Ialltoall_sched_intra_pairwise(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, comm_ptr, s);
}
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
fn_exit:
return mpi_errno;
fn_fail:
goto fn_exit;
}
#undef FUNCNAME
#define FUNCNAME MPIR_Ialltoall_sched_inter_auto
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ialltoall_sched_inter_auto(const void *sendbuf, int sendcount, MPI_Datatype
sendtype, void *recvbuf, int recvcount, MPI_Datatype recvtype,
MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
int mpi_errno = MPI_SUCCESS;
mpi_errno = MPIR_Ialltoall_sched_inter_pairwise_exchange(sendbuf, sendcount,
sendtype, recvbuf, recvcount, recvtype,
comm_ptr, s);
return mpi_errno;
}
#undef FUNCNAME
#define FUNCNAME MPIR_Ialltoall_sched_impl
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ialltoall_sched_impl(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
void *recvbuf, int recvcount, MPI_Datatype recvtype,
MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
int mpi_errno = MPI_SUCCESS;
if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM) {
/* intracommunicator */
switch (MPIR_Ialltoall_intra_algo_choice) {
case MPIR_IALLTOALL_INTRA_ALGO_BRUCKS:
mpi_errno = MPIR_Ialltoall_sched_intra_brucks(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype,
comm_ptr, s);
break;
case MPIR_IALLTOALL_INTRA_ALGO_INPLACE:
mpi_errno = MPIR_Ialltoall_sched_intra_inplace(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype,
comm_ptr, s);
break;
case MPIR_IALLTOALL_INTRA_ALGO_PAIRWISE:
mpi_errno = MPIR_Ialltoall_sched_intra_pairwise(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype,
comm_ptr, s);
break;
case MPIR_IALLTOALL_INTRA_ALGO_PERMUTED_SENDRECV:
mpi_errno =
MPIR_Ialltoall_sched_intra_permuted_sendrecv(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype,
comm_ptr, s);
break;
case MPIR_IALLTOALL_INTRA_ALGO_AUTO:
MPL_FALLTHROUGH;
default:
mpi_errno = MPIR_Ialltoall_sched_intra_auto(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype, comm_ptr,
s);
break;
}
} else {
/* intercommunicator */
switch (MPIR_Ialltoall_inter_algo_choice) {
case MPIR_IALLTOALL_INTER_ALGO_PAIRWISE_EXCHANGE:
mpi_errno =
MPIR_Ialltoall_sched_inter_pairwise_exchange(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype,
comm_ptr, s);
break;
case MPIR_IALLTOALL_INTER_ALGO_AUTO:
MPL_FALLTHROUGH;
default:
mpi_errno = MPIR_Ialltoall_sched_inter_auto(sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype, comm_ptr,
s);
break;
}
}
return mpi_errno;
}
#undef FUNCNAME
#define FUNCNAME MPIR_Ialltoall_sched
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ialltoall_sched(const void *sendbuf, int sendcount, MPI_Datatype sendtype, void *recvbuf,
int recvcount, MPI_Datatype recvtype, MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
int mpi_errno = MPI_SUCCESS;
if (MPIR_CVAR_IALLTOALL_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {
mpi_errno = MPID_Ialltoall_sched(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,
comm_ptr, s);
} else {
mpi_errno = MPIR_Ialltoall_sched_impl(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, comm_ptr, s);
}
return mpi_errno;
}
#undef FUNCNAME
#define FUNCNAME MPIR_Ialltoall_impl
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ialltoall_impl(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, MPIR_Comm * comm_ptr, MPIR_Request ** request)
{
int mpi_errno = MPI_SUCCESS;
int tag = -1;
MPIR_Sched_t s = MPIR_SCHED_NULL;
*request = NULL;
mpi_errno = MPIR_Sched_next_tag(comm_ptr, &tag);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
mpi_errno = MPIR_Sched_create(&s);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
mpi_errno =
MPIR_Ialltoall_sched(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, comm_ptr,
s);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
mpi_errno = MPIR_Sched_start(&s, comm_ptr, tag, request);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
fn_exit:
return mpi_errno;
fn_fail:
goto fn_exit;
}
#undef FUNCNAME
#define FUNCNAME MPIR_Ialltoall
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ialltoall(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
void *recvbuf, int recvcount, MPI_Datatype recvtype,
MPIR_Comm * comm_ptr, MPIR_Request ** request)
{
int mpi_errno = MPI_SUCCESS;
if (MPIR_CVAR_IALLTOALL_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {
mpi_errno = MPID_Ialltoall(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,
comm_ptr, request);
} else {
mpi_errno = MPIR_Ialltoall_impl(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype,
comm_ptr, request);
}
return mpi_errno;
}
#endif /* MPICH_MPI_FROM_PMPI */
#undef FUNCNAME
#define FUNCNAME MPI_Ialltoall
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
/*@
MPI_Ialltoall - Sends data from all to all processes in a nonblocking way
Input Parameters:
+ sendbuf - starting address of the send buffer (choice)
. sendcount - number of elements in send buffer (non-negative integer)
. sendtype - data type of send buffer elements (handle)
. recvcount - number of elements received from any process (non-negative integer)
. recvtype - data type of receive buffer elements (handle)
- comm - communicator (handle)
Output Parameters:
+ recvbuf - starting address of the receive buffer (choice)
- request - communication request (handle)
.N ThreadSafe
.N Fortran
.N Errors
@*/
int MPI_Ialltoall(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
void *recvbuf, int recvcount, MPI_Datatype recvtype,
MPI_Comm comm, MPI_Request * request)
{
int mpi_errno = MPI_SUCCESS;
MPIR_Comm *comm_ptr = NULL;
MPIR_Request *request_ptr = NULL;
MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_IALLTOALL);
MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_IALLTOALL);
/* Validate parameters, especially handles needing to be converted */
#ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
if (sendbuf != MPI_IN_PLACE) {
MPIR_ERRTEST_COUNT(sendcount, mpi_errno);
MPIR_ERRTEST_DATATYPE(sendtype, "sendtype", mpi_errno);
}
MPIR_ERRTEST_COUNT(recvcount, mpi_errno);
MPIR_ERRTEST_DATATYPE(recvtype, "recvtype", mpi_errno);
MPIR_ERRTEST_COMM(comm, mpi_errno);
/* TODO more checks may be appropriate */
}
MPID_END_ERROR_CHECKS;
}
#endif /* HAVE_ERROR_CHECKING */
/* Convert MPI object handles to object pointers */
MPIR_Comm_get_ptr(comm, comm_ptr);
/* Validate parameters and objects (post conversion) */
#ifdef HAVE_ERROR_CHECKING
{
MPID_BEGIN_ERROR_CHECKS;
{
MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, FALSE);
if (mpi_errno != MPI_SUCCESS)
goto fn_fail;
if (sendbuf != MPI_IN_PLACE && HANDLE_GET_KIND(sendtype) != HANDLE_KIND_BUILTIN) {
MPIR_Datatype *sendtype_ptr = NULL;
MPIR_Datatype_get_ptr(sendtype, sendtype_ptr);
MPIR_Datatype_valid_ptr(sendtype_ptr, mpi_errno);
if (mpi_errno != MPI_SUCCESS)
goto fn_fail;
MPIR_Datatype_committed_ptr(sendtype_ptr, mpi_errno);
if (mpi_errno != MPI_SUCCESS)
goto fn_fail;
}
if (HANDLE_GET_KIND(recvtype) != HANDLE_KIND_BUILTIN) {
MPIR_Datatype *recvtype_ptr = NULL;
MPIR_Datatype_get_ptr(recvtype, recvtype_ptr);
MPIR_Datatype_valid_ptr(recvtype_ptr, mpi_errno);
if (mpi_errno != MPI_SUCCESS)
goto fn_fail;
MPIR_Datatype_committed_ptr(recvtype_ptr, mpi_errno);
if (mpi_errno != MPI_SUCCESS)
goto fn_fail;
}
MPIR_ERRTEST_ARGNULL(request, "request", mpi_errno);
if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM &&
sendbuf != MPI_IN_PLACE &&
sendcount == recvcount && sendtype == recvtype && sendcount != 0)
MPIR_ERRTEST_ALIAS_COLL(sendbuf, recvbuf, mpi_errno);
/* TODO more checks may be appropriate (counts, in_place, etc) */
}
MPID_END_ERROR_CHECKS;
}
#endif /* HAVE_ERROR_CHECKING */
/* ... body of routine ... */
mpi_errno =
MPIR_Ialltoall(sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, comm_ptr,
&request_ptr);
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
/* create a complete request, if needed */
if (!request_ptr)
request_ptr = MPIR_Request_create_complete(MPIR_REQUEST_KIND__COLL);
/* return the handle of the request to the user */
*request = request_ptr->handle;
/* ... end of body of routine ... */
fn_exit:
MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_IALLTOALL);
MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
return mpi_errno;
fn_fail:
/* --BEGIN ERROR HANDLING-- */
#ifdef HAVE_ERROR_CHECKING
{
mpi_errno =
MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,
"**mpi_ialltoall", "**mpi_ialltoall %p %d %D %p %d %D %C %p",
sendbuf, sendcount, sendtype, recvbuf, recvcount, recvtype, comm,
request);
}
#endif
mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);
goto fn_exit;
/* --END ERROR HANDLING-- */
}