1 #include <../src/vec/is/sf/impls/basic/allgatherv/sfallgatherv.h> 2 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; 5 6 PETSC_INTERN PetscErrorCode PetscSFBcastBegin_Gather(PetscSF, MPI_Datatype, PetscMemType, const void *, PetscMemType, void *, MPI_Op); 7 8 PetscErrorCode PetscSFSetUp_Allgather(PetscSF sf) 9 { 10 PetscInt i; 11 PetscSF_Allgather *dat = (PetscSF_Allgather *)sf->data; 12 13 PetscFunctionBegin; 14 for (i = PETSCSF_LOCAL; i <= PETSCSF_REMOTE; i++) { 15 sf->leafbuflen[i] = 0; 16 sf->leafstart[i] = 0; 17 sf->leafcontig[i] = PETSC_TRUE; 18 sf->leafdups[i] = PETSC_FALSE; 19 dat->rootbuflen[i] = 0; 20 dat->rootstart[i] = 0; 21 dat->rootcontig[i] = PETSC_TRUE; 22 dat->rootdups[i] = PETSC_FALSE; 23 } 24 25 sf->leafbuflen[PETSCSF_REMOTE] = sf->nleaves; 26 dat->rootbuflen[PETSCSF_REMOTE] = sf->nroots; 27 sf->persistent = PETSC_FALSE; 28 sf->nleafreqs = 0; /* MPI collectives only need one request. We treat it as a root request. */ 29 dat->nrootreqs = 1; 30 PetscFunctionReturn(PETSC_SUCCESS); 31 } 32 33 static PetscErrorCode PetscSFBcastBegin_Allgather(PetscSF sf, MPI_Datatype unit, PetscMemType rootmtype, const void *rootdata, PetscMemType leafmtype, void *leafdata, MPI_Op op) 34 { 35 PetscSFLink link; 36 PetscMPIInt sendcount; 37 MPI_Comm comm; 38 void *rootbuf = NULL, *leafbuf = NULL; /* buffer seen by MPI */ 39 MPI_Request *req; 40 41 PetscFunctionBegin; 42 PetscCall(PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op, PETSCSF_BCAST, &link)); 43 PetscCall(PetscSFLinkPackRootData(sf, link, PETSCSF_REMOTE, rootdata)); 44 PetscCall(PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */)); 45 PetscCall(PetscObjectGetComm((PetscObject)sf, &comm)); 46 PetscCall(PetscMPIIntCast(sf->nroots, &sendcount)); 47 PetscCall(PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_ROOT2LEAF, &rootbuf, &leafbuf, &req, NULL)); 48 PetscCall(PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_ROOT2LEAF)); 49 PetscCallMPI(MPIU_Iallgather(rootbuf, sendcount, unit, leafbuf, sendcount, unit, comm, req)); 50 PetscFunctionReturn(PETSC_SUCCESS); 51 } 52 53 static PetscErrorCode PetscSFReduceBegin_Allgather(PetscSF sf, MPI_Datatype unit, PetscMemType leafmtype, const void *leafdata, PetscMemType rootmtype, void *rootdata, MPI_Op op) 54 { 55 PetscSFLink link; 56 PetscInt rstart; 57 MPI_Comm comm; 58 PetscMPIInt rank, count, recvcount; 59 void *rootbuf = NULL, *leafbuf = NULL; /* buffer seen by MPI */ 60 PetscSF_Allgather *dat = (PetscSF_Allgather *)sf->data; 61 MPI_Request *req; 62 63 PetscFunctionBegin; 64 PetscCall(PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op, PETSCSF_REDUCE, &link)); 65 if (op == MPI_REPLACE) { 66 /* REPLACE is only meaningful when all processes have the same leafdata to reduce. Therefore copy from local leafdata is fine */ 67 PetscCall(PetscLayoutGetRange(sf->map, &rstart, NULL)); 68 PetscCall((*link->Memcpy)(link, rootmtype, rootdata, leafmtype, (const char *)leafdata + (size_t)rstart * link->unitbytes, (size_t)sf->nroots * link->unitbytes)); 69 if (PetscMemTypeDevice(leafmtype) && PetscMemTypeHost(rootmtype)) PetscCall((*link->SyncStream)(link)); /* Sync the device to host memcpy */ 70 } else { 71 PetscCall(PetscObjectGetComm((PetscObject)sf, &comm)); 72 PetscCallMPI(MPI_Comm_rank(comm, &rank)); 73 PetscCall(PetscSFLinkPackLeafData(sf, link, PETSCSF_REMOTE, leafdata)); 74 PetscCall(PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */)); 75 PetscCall(PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_LEAF2ROOT, &rootbuf, &leafbuf, &req, NULL)); 76 PetscCall(PetscMPIIntCast(dat->rootbuflen[PETSCSF_REMOTE], &recvcount)); 77 if (rank == 0 && !link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi]) { 78 PetscCall(PetscSFMalloc(sf, link->leafmtype_mpi, sf->leafbuflen[PETSCSF_REMOTE] * link->unitbytes, (void **)&link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi])); 79 } 80 if (rank == 0 && link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi] == leafbuf) leafbuf = MPI_IN_PLACE; 81 PetscCall(PetscMPIIntCast(sf->nleaves * link->bs, &count)); 82 PetscCall(PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_LEAF2ROOT)); 83 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 */ 84 PetscCallMPI(MPIU_Iscatter(link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi], recvcount, unit, rootbuf, recvcount, unit, 0 /*rank 0*/, comm, req)); 85 } 86 PetscFunctionReturn(PETSC_SUCCESS); 87 } 88 89 static PetscErrorCode PetscSFBcastToZero_Allgather(PetscSF sf, MPI_Datatype unit, PetscMemType rootmtype, const void *rootdata, PetscMemType leafmtype, void *leafdata) 90 { 91 PetscSFLink link; 92 PetscMPIInt rank; 93 94 PetscFunctionBegin; 95 PetscCall(PetscSFBcastBegin_Gather(sf, unit, rootmtype, rootdata, leafmtype, leafdata, MPI_REPLACE)); 96 PetscCall(PetscSFLinkGetInUse(sf, unit, rootdata, leafdata, PETSC_OWN_POINTER, &link)); 97 PetscCall(PetscSFLinkFinishCommunication(sf, link, PETSCSF_ROOT2LEAF)); 98 PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)sf), &rank)); 99 if (rank == 0 && PetscMemTypeDevice(leafmtype) && !sf->use_gpu_aware_mpi) { 100 PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, leafdata, PETSC_MEMTYPE_HOST, link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST], sf->leafbuflen[PETSCSF_REMOTE] * link->unitbytes)); 101 } 102 PetscCall(PetscSFLinkReclaim(sf, &link)); 103 PetscFunctionReturn(PETSC_SUCCESS); 104 } 105 106 PETSC_INTERN PetscErrorCode PetscSFCreate_Allgather(PetscSF sf) 107 { 108 PetscSF_Allgather *dat = (PetscSF_Allgather *)sf->data; 109 110 PetscFunctionBegin; 111 sf->ops->BcastEnd = PetscSFBcastEnd_Basic; 112 sf->ops->ReduceEnd = PetscSFReduceEnd_Allgatherv; 113 114 /* Inherit from Allgatherv */ 115 sf->ops->Reset = PetscSFReset_Allgatherv; 116 sf->ops->Destroy = PetscSFDestroy_Allgatherv; 117 sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Allgatherv; 118 sf->ops->FetchAndOpEnd = PetscSFFetchAndOpEnd_Allgatherv; 119 sf->ops->GetRootRanks = PetscSFGetRootRanks_Allgatherv; 120 sf->ops->CreateLocalSF = PetscSFCreateLocalSF_Allgatherv; 121 sf->ops->GetGraph = PetscSFGetGraph_Allgatherv; 122 sf->ops->GetLeafRanks = PetscSFGetLeafRanks_Allgatherv; 123 124 /* Allgather stuff */ 125 sf->ops->SetUp = PetscSFSetUp_Allgather; 126 sf->ops->BcastBegin = PetscSFBcastBegin_Allgather; 127 sf->ops->ReduceBegin = PetscSFReduceBegin_Allgather; 128 sf->ops->BcastToZero = PetscSFBcastToZero_Allgather; 129 130 PetscCall(PetscNew(&dat)); 131 sf->data = (void *)dat; 132 PetscFunctionReturn(PETSC_SUCCESS); 133 } 134