/**
* Alltoall basic_linear (STARMPI:alltoall-simple)
**/
int smpi_coll_tuned_alltoall_basic_linear(void *sendbuf, int sendcount,
MPI_Datatype sendtype,
void *recvbuf, int recvcount,
MPI_Datatype recvtype,
MPI_Comm comm)
{
int system_tag = 888;
int i, rank, size, err, count;
MPI_Aint lb = 0, sendext = 0, recvext = 0;
MPI_Request *requests;
/* Initialize. */
rank = smpi_comm_rank(comm);
size = smpi_comm_size(comm);
XBT_DEBUG("<%d> algorithm alltoall_basic_linear() called.", rank);
smpi_datatype_extent(sendtype, &lb, &sendext);
smpi_datatype_extent(recvtype, &lb, &recvext);
/* simple optimization */
err = smpi_datatype_copy((char *)sendbuf + rank * sendcount * sendext,
sendcount, sendtype,
(char *)recvbuf + rank * recvcount * recvext,
recvcount, recvtype);
if (err == MPI_SUCCESS && size > 1) {
/* Initiate all send/recv to/from others. */
requests = xbt_new(MPI_Request, 2 * (size - 1));
/* Post all receives first -- a simple optimization */
count = 0;
for (i = (rank + 1) % size; i != rank; i = (i + 1) % size) {
requests[count] =
smpi_irecv_init((char *)recvbuf + i * recvcount * recvext, recvcount,
recvtype, i, system_tag, comm);
count++;
}
/* Now post all sends in reverse order
* - We would like to minimize the search time through message queue
* when messages actually arrive in the order in which they were posted.
* TODO: check the previous assertion
*/
for (i = (rank + size - 1) % size; i != rank; i = (i + size - 1) % size) {
requests[count] =
smpi_isend_init((char *)sendbuf + i * sendcount * sendext, sendcount,
sendtype, i, system_tag, comm);
count++;
}
/* Wait for them all. */
smpi_mpi_startall(count, requests);
XBT_DEBUG("<%d> wait for %d requests", rank, count);
smpi_mpi_waitall(count, requests, MPI_STATUS_IGNORE);
for(i = 0; i < count; i++) {
if(requests[i]!=MPI_REQUEST_NULL) smpi_mpi_request_free(&requests[i]);
}
xbt_free(requests);
}
return err;
}
/*
* Linear functions are copied from the basic coll module. For
* some small number of nodes and/or small data sizes they are just as
* fast as tuned/tree based segmenting operations and as such may be
* selected by the decision functions. These are copied into this module
* due to the way we select modules in V1. i.e. in V2 we will handle this
* differently and so will not have to duplicate code.
* GEF Oct05 after asking Jeff.
*/
int
smpi_coll_tuned_alltoallv_ompi_basic_linear(void *sbuf, int *scounts, int *sdisps,
MPI_Datatype sdtype,
void *rbuf, int *rcounts, int *rdisps,
MPI_Datatype rdtype,
MPI_Comm comm)
{
int i, size, rank;
char *psnd, *prcv;
int nreqs;
ptrdiff_t sext, rext;
MPI_Request *preq;
size = smpi_comm_size(comm);
rank = smpi_comm_rank(comm);
MPI_Request *ireqs= xbt_malloc(sizeof(MPI_Request) * size * 2);
XBT_DEBUG(
"coll:tuned:alltoallv_intra_basic_linear rank %d", rank);
sext=smpi_datatype_get_extent(sdtype);
rext=smpi_datatype_get_extent(rdtype);
/* Simple optimization - handle send to self first */
psnd = ((char *) sbuf) + (sdisps[rank] * sext);
prcv = ((char *) rbuf) + (rdisps[rank] * rext);
if (0 != scounts[rank]) {
smpi_datatype_copy(psnd, scounts[rank], sdtype,
prcv, rcounts[rank], rdtype);
}
/* If only one process, we're done. */
if (1 == size) {
return MPI_SUCCESS;
}
/* Now, initiate all send/recv to/from others. */
nreqs = 0;
preq = ireqs;
/* Post all receives first */
for (i = 0; i < size; ++i) {
if (i == rank || 0 == rcounts[i]) {
continue;
}
prcv = ((char *) rbuf) + (rdisps[i] * rext);
*preq = smpi_irecv_init(prcv, rcounts[i], rdtype,
i, COLL_TAG_ALLTOALLV, comm
);
preq++;
++nreqs;
}
/* Now post all sends */
for (i = 0; i < size; ++i) {
if (i == rank || 0 == scounts[i]) {
continue;
}
psnd = ((char *) sbuf) + (sdisps[i] * sext);
*preq=smpi_isend_init(psnd, scounts[i], sdtype,
i, COLL_TAG_ALLTOALLV, comm
);
preq++;
++nreqs;
}
/* Start your engines. This will never return an error. */
smpi_mpi_startall(nreqs, ireqs);
/* Wait for them all. If there's an error, note that we don't care
* what the error was -- just that there *was* an error. The PML
* will finish all requests, even if one or more of them fail.
* i.e., by the end of this call, all the requests are free-able.
* So free them anyway -- even if there was an error, and return the
* error after we free everything. */
smpi_mpi_waitall(nreqs, ireqs,
MPI_STATUSES_IGNORE);
/* Free the requests. */
for (i = 0; i < nreqs; ++i) {
if(ireqs[i]!=MPI_REQUEST_NULL)smpi_mpi_request_free(&ireqs[i]);
}
return MPI_SUCCESS;
}
int smpi_coll_basic_alltoallv(void *sendbuf, int *sendcounts,
int *senddisps, MPI_Datatype sendtype,
void *recvbuf, int *recvcounts,
int *recvdisps, MPI_Datatype recvtype,
MPI_Comm comm)
{
int system_tag = 889;
int i, rank, size, err, count;
MPI_Aint lb = 0, sendext = 0, recvext = 0;
MPI_Request *requests;
/* Initialize. */
rank = smpi_comm_rank(comm);
size = smpi_comm_size(comm);
XBT_DEBUG("<%d> algorithm basic_alltoallv() called.", rank);
smpi_datatype_extent(sendtype, &lb, &sendext);
smpi_datatype_extent(recvtype, &lb, &recvext);
/* Local copy from self */
err =
smpi_datatype_copy((char *)sendbuf + senddisps[rank] * sendext,
sendcounts[rank], sendtype,
(char *)recvbuf + recvdisps[rank] * recvext,
recvcounts[rank], recvtype);
if (err == MPI_SUCCESS && size > 1) {
/* Initiate all send/recv to/from others. */
requests = xbt_new(MPI_Request, 2 * (size - 1));
count = 0;
/* Create all receives that will be posted first */
for (i = 0; i < size; ++i) {
if (i == rank || recvcounts[i] == 0) {
XBT_DEBUG
("<%d> skip request creation [src = %d, recvcounts[src] = %d]",
rank, i, recvcounts[i]);
continue;
}
requests[count] =
smpi_irecv_init((char *)recvbuf + recvdisps[i] * recvext,
recvcounts[i], recvtype, i, system_tag, comm);
count++;
}
/* Now create all sends */
for (i = 0; i < size; ++i) {
if (i == rank || sendcounts[i] == 0) {
XBT_DEBUG
("<%d> skip request creation [dst = %d, sendcounts[dst] = %d]",
rank, i, sendcounts[i]);
continue;
}
requests[count] =
smpi_isend_init((char *)sendbuf + senddisps[i] * sendext,
sendcounts[i], sendtype, i, system_tag, comm);
count++;
}
/* Wait for them all. */
smpi_mpi_startall(count, requests);
XBT_DEBUG("<%d> wait for %d requests", rank, count);
smpi_mpi_waitall(count, requests, MPI_STATUS_IGNORE);
for(i = 0; i < count; i++) {
if(requests[i]!=MPI_REQUEST_NULL) smpi_mpi_request_free(&requests[i]);
}
xbt_free(requests);
}
return err;
}