1 /*
2 * Copyright (C) by Argonne National Laboratory
3 * See COPYRIGHT in top-level directory
4 */
5
6 #include "mpiimpl.h"
7
8 /* Local reduce remote send
9 *
10 * Remote group does a local intracommunicator reduce to rank 0. Rank
11 * 0 then sends data to root.
12 */
13
MPIR_Ireduce_inter_sched_local_reduce_remote_send(const void * sendbuf,void * recvbuf,int count,MPI_Datatype datatype,MPI_Op op,int root,MPIR_Comm * comm_ptr,MPIR_Sched_t s)14 int MPIR_Ireduce_inter_sched_local_reduce_remote_send(const void *sendbuf, void *recvbuf, int count,
15 MPI_Datatype datatype, MPI_Op op, int root,
16 MPIR_Comm * comm_ptr, MPIR_Sched_t s)
17 {
18 int mpi_errno = MPI_SUCCESS;
19 int rank;
20 MPI_Aint true_lb, true_extent, extent;
21 void *tmp_buf = NULL;
22 MPIR_SCHED_CHKPMEM_DECL(1);
23
24 MPIR_Assert(comm_ptr->comm_kind == MPIR_COMM_KIND__INTERCOMM);
25
26 if (root == MPI_PROC_NULL) {
27 /* local processes other than root do nothing */
28 return MPI_SUCCESS;
29 }
30
31 if (root == MPI_ROOT) {
32 /* root receives data from rank 0 on remote group */
33 mpi_errno = MPIR_Sched_recv(recvbuf, count, datatype, 0, comm_ptr, s);
34 MPIR_ERR_CHECK(mpi_errno);
35 mpi_errno = MPIR_Sched_barrier(s);
36 MPIR_ERR_CHECK(mpi_errno);
37 } else {
38 /* remote group. Rank 0 allocates temporary buffer, does
39 * local intracommunicator reduce, and then sends the data
40 * to root. */
41 rank = comm_ptr->rank;
42
43 if (rank == 0) {
44 MPIR_Type_get_true_extent_impl(datatype, &true_lb, &true_extent);
45
46 MPIR_Datatype_get_extent_macro(datatype, extent);
47 MPIR_SCHED_CHKPMEM_MALLOC(tmp_buf, void *, count * (MPL_MAX(extent, true_extent)),
48 mpi_errno, "temporary buffer", MPL_MEM_BUFFER);
49 /* adjust for potential negative lower bound in datatype */
50 tmp_buf = (void *) ((char *) tmp_buf - true_lb);
51 }
52
53 if (!comm_ptr->local_comm) {
54 mpi_errno = MPII_Setup_intercomm_localcomm(comm_ptr);
55 MPIR_ERR_CHECK(mpi_errno);
56 }
57
58 mpi_errno =
59 MPIR_Ireduce_sched_auto(sendbuf, tmp_buf, count, datatype, op, 0, comm_ptr->local_comm,
60 s);
61 MPIR_ERR_CHECK(mpi_errno);
62 mpi_errno = MPIR_Sched_barrier(s);
63 MPIR_ERR_CHECK(mpi_errno);
64
65 if (rank == 0) {
66 mpi_errno = MPIR_Sched_send(tmp_buf, count, datatype, root, comm_ptr, s);
67 MPIR_ERR_CHECK(mpi_errno);
68 mpi_errno = MPIR_Sched_barrier(s);
69 MPIR_ERR_CHECK(mpi_errno);
70 }
71 }
72
73 MPIR_SCHED_CHKPMEM_COMMIT(s);
74 fn_exit:
75 return mpi_errno;
76 fn_fail:
77 MPIR_SCHED_CHKPMEM_REAP(s);
78 goto fn_exit;
79 }
80