Actual source code: sfallgather.c
1: #include <../src/vec/is/sf/impls/basic/allgatherv/sfallgatherv.h>
3: /* Reuse the type. The difference is some fields (i.e., displs, recvcounts) are not used in Allgather on rank != 0, which is not a big deal */
4: typedef PetscSF_Allgatherv PetscSF_Allgather;
6: PetscErrorCode PetscSFSetUp_Allgather(PetscSF sf)
7: {
8: PetscInt i;
9: PetscSF_Allgather *dat = (PetscSF_Allgather *)sf->data;
11: PetscFunctionBegin;
12: for (i = PETSCSF_LOCAL; i <= PETSCSF_REMOTE; i++) {
13: sf->leafbuflen[i] = 0;
14: sf->leafstart[i] = 0;
15: sf->leafcontig[i] = PETSC_TRUE;
16: sf->leafdups[i] = PETSC_FALSE;
17: dat->rootbuflen[i] = 0;
18: dat->rootstart[i] = 0;
19: dat->rootcontig[i] = PETSC_TRUE;
20: dat->rootdups[i] = PETSC_FALSE;
21: }
23: sf->leafbuflen[PETSCSF_REMOTE] = sf->nleaves;
24: dat->rootbuflen[PETSCSF_REMOTE] = sf->nroots;
25: sf->persistent = PETSC_FALSE;
26: sf->nleafreqs = 0; /* MPI collectives only need one request. We treat it as a root request. */
27: dat->nrootreqs = 1;
28: PetscFunctionReturn(PETSC_SUCCESS);
29: }
31: static PetscErrorCode PetscSFBcastBegin_Allgather(PetscSF sf, MPI_Datatype unit, PetscMemType rootmtype, const void *rootdata, PetscMemType leafmtype, void *leafdata, MPI_Op op)
32: {
33: PetscSFLink link;
34: PetscMPIInt sendcount;
35: MPI_Comm comm;
36: void *rootbuf = NULL, *leafbuf = NULL; /* buffer seen by MPI */
37: MPI_Request *req = NULL;
39: PetscFunctionBegin;
40: PetscCall(PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op, PETSCSF_BCAST, &link));
41: PetscCall(PetscSFLinkPackRootData(sf, link, PETSCSF_REMOTE, rootdata));
42: PetscCall(PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */));
43: PetscCall(PetscObjectGetComm((PetscObject)sf, &comm));
44: PetscCall(PetscMPIIntCast(sf->nroots, &sendcount));
45: PetscCall(PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_ROOT2LEAF, &rootbuf, &leafbuf, &req, NULL));
46: PetscCall(PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_ROOT2LEAF));
47: PetscCallMPI(MPIU_Iallgather(rootbuf, sendcount, unit, leafbuf, sendcount, unit, comm, req));
48: PetscFunctionReturn(PETSC_SUCCESS);
49: }
51: static PetscErrorCode PetscSFReduceBegin_Allgather(PetscSF sf, MPI_Datatype unit, PetscMemType leafmtype, const void *leafdata, PetscMemType rootmtype, void *rootdata, MPI_Op op)
52: {
53: PetscSFLink link;
54: PetscInt rstart;
55: MPI_Comm comm;
56: PetscMPIInt rank, count, recvcount;
57: void *rootbuf = NULL, *leafbuf = NULL; /* buffer seen by MPI */
58: PetscSF_Allgather *dat = (PetscSF_Allgather *)sf->data;
59: MPI_Request *req = NULL;
61: PetscFunctionBegin;
62: PetscCall(PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op, PETSCSF_REDUCE, &link));
63: if (op == MPI_REPLACE) {
64: /* REPLACE is only meaningful when all processes have the same leafdata to reduce. Therefore copy from local leafdata is fine */
65: PetscCall(PetscLayoutGetRange(sf->map, &rstart, NULL));
66: PetscCall((*link->Memcpy)(link, rootmtype, rootdata, leafmtype, (const char *)leafdata + (size_t)rstart * link->unitbytes, (size_t)sf->nroots * link->unitbytes));
67: if (PetscMemTypeDevice(leafmtype) && PetscMemTypeHost(rootmtype)) PetscCall((*link->SyncStream)(link)); /* Sync the device to host memcpy */
68: } else {
69: PetscCall(PetscObjectGetComm((PetscObject)sf, &comm));
70: PetscCallMPI(MPI_Comm_rank(comm, &rank));
71: PetscCall(PetscSFLinkPackLeafData(sf, link, PETSCSF_REMOTE, leafdata));
72: PetscCall(PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */));
73: PetscCall(PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_LEAF2ROOT, &rootbuf, &leafbuf, &req, NULL));
74: PetscCall(PetscMPIIntCast(dat->rootbuflen[PETSCSF_REMOTE], &recvcount));
75: if (rank == 0 && !link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi]) {
76: PetscCall(PetscSFMalloc(sf, link->leafmtype_mpi, sf->leafbuflen[PETSCSF_REMOTE] * link->unitbytes, (void **)&link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi]));
77: }
78: if (rank == 0 && link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi] == leafbuf) leafbuf = MPI_IN_PLACE;
79: PetscCall(PetscMPIIntCast(sf->nleaves * link->bs, &count));
80: PetscCall(PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_LEAF2ROOT));
81: PetscCallMPI(MPI_Reduce(leafbuf, link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi], count, link->basicunit, op, 0, comm)); /* Must do reduce with MPI builtin datatype basicunit */
82: PetscCallMPI(MPIU_Iscatter(link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi], recvcount, unit, rootbuf, recvcount, unit, 0 /*rank 0*/, comm, req));
83: }
84: PetscFunctionReturn(PETSC_SUCCESS);
85: }
87: static PetscErrorCode PetscSFBcastToZero_Allgather(PetscSF sf, MPI_Datatype unit, PetscMemType rootmtype, const void *rootdata, PetscMemType leafmtype, void *leafdata)
88: {
89: PetscSFLink link;
90: PetscMPIInt rank;
91: PetscMPIInt sendcount;
92: MPI_Comm comm;
93: void *rootbuf = NULL, *leafbuf = NULL;
94: MPI_Request *req = NULL;
96: PetscFunctionBegin;
97: PetscCall(PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, MPI_REPLACE, PETSCSF_BCAST, &link));
98: PetscCall(PetscSFLinkPackRootData(sf, link, PETSCSF_REMOTE, rootdata));
99: PetscCall(PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */));
100: PetscCall(PetscObjectGetComm((PetscObject)sf, &comm));
101: PetscCall(PetscMPIIntCast(sf->nroots, &sendcount));
102: PetscCall(PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_ROOT2LEAF, &rootbuf, &leafbuf, &req, NULL));
103: PetscCall(PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_ROOT2LEAF));
104: PetscCallMPI(MPIU_Igather(rootbuf == leafbuf ? MPI_IN_PLACE : rootbuf, sendcount, unit, leafbuf, sendcount, unit, 0 /*rank 0*/, comm, req));
105: PetscCall(PetscSFLinkGetInUse(sf, unit, rootdata, leafdata, PETSC_OWN_POINTER, &link));
106: PetscCall(PetscSFLinkFinishCommunication(sf, link, PETSCSF_ROOT2LEAF));
107: PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)sf), &rank));
108: if (rank == 0 && PetscMemTypeDevice(leafmtype) && !sf->use_gpu_aware_mpi) {
109: PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, leafdata, PETSC_MEMTYPE_HOST, link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST], sf->leafbuflen[PETSCSF_REMOTE] * link->unitbytes));
110: }
111: PetscCall(PetscSFLinkReclaim(sf, &link));
112: PetscFunctionReturn(PETSC_SUCCESS);
113: }
115: PETSC_INTERN PetscErrorCode PetscSFCreate_Allgather(PetscSF sf)
116: {
117: PetscSF_Allgather *dat = (PetscSF_Allgather *)sf->data;
119: PetscFunctionBegin;
120: sf->ops->BcastEnd = PetscSFBcastEnd_Basic;
121: sf->ops->ReduceEnd = PetscSFReduceEnd_Allgatherv;
123: /* Inherit from Allgatherv */
124: sf->ops->Reset = PetscSFReset_Allgatherv;
125: sf->ops->Destroy = PetscSFDestroy_Allgatherv;
126: sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Allgatherv;
127: sf->ops->FetchAndOpEnd = PetscSFFetchAndOpEnd_Allgatherv;
128: sf->ops->GetRootRanks = PetscSFGetRootRanks_Allgatherv;
129: sf->ops->CreateLocalSF = PetscSFCreateLocalSF_Allgatherv;
130: sf->ops->GetGraph = PetscSFGetGraph_Allgatherv;
131: sf->ops->GetLeafRanks = PetscSFGetLeafRanks_Allgatherv;
133: /* Allgather stuff */
134: sf->ops->SetUp = PetscSFSetUp_Allgather;
135: sf->ops->BcastBegin = PetscSFBcastBegin_Allgather;
136: sf->ops->ReduceBegin = PetscSFReduceBegin_Allgather;
137: sf->ops->BcastToZero = PetscSFBcastToZero_Allgather;
139: sf->collective = PETSC_TRUE;
141: PetscCall(PetscNew(&dat));
142: sf->data = (void *)dat;
143: PetscFunctionReturn(PETSC_SUCCESS);
144: }