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: PETSC_INTERN PetscErrorCode PetscSFBcastBegin_Gather(PetscSF,MPI_Datatype,PetscMemType,const void*,PetscMemType,void*,MPI_Op);
8: PetscErrorCode PetscSFSetUp_Allgather(PetscSF sf)
9: {
10: PetscInt i;
11: PetscSF_Allgather *dat = (PetscSF_Allgather*)sf->data;
13: for (i=PETSCSF_LOCAL; i<=PETSCSF_REMOTE; i++) {
14: sf->leafbuflen[i] = 0;
15: sf->leafstart[i] = 0;
16: sf->leafcontig[i] = PETSC_TRUE;
17: sf->leafdups[i] = PETSC_FALSE;
18: dat->rootbuflen[i] = 0;
19: dat->rootstart[i] = 0;
20: dat->rootcontig[i] = PETSC_TRUE;
21: dat->rootdups[i] = PETSC_FALSE;
22: }
24: sf->leafbuflen[PETSCSF_REMOTE] = sf->nleaves;
25: dat->rootbuflen[PETSCSF_REMOTE] = sf->nroots;
26: sf->persistent = PETSC_FALSE;
27: sf->nleafreqs = 0; /* MPI collectives only need one request. We treat it as a root request. */
28: dat->nrootreqs = 1;
29: return 0;
30: }
32: static PetscErrorCode PetscSFBcastBegin_Allgather(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,const void *rootdata,PetscMemType leafmtype,void *leafdata,MPI_Op op)
33: {
34: PetscSFLink link;
35: PetscMPIInt sendcount;
36: MPI_Comm comm;
37: void *rootbuf = NULL,*leafbuf = NULL; /* buffer seen by MPI */
38: MPI_Request *req;
40: PetscSFLinkCreate(sf,unit,rootmtype,rootdata,leafmtype,leafdata,op,PETSCSF_BCAST,&link);
41: PetscSFLinkPackRootData(sf,link,PETSCSF_REMOTE,rootdata);
42: PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(sf,link,PETSC_TRUE/* device2host before sending */);
43: PetscObjectGetComm((PetscObject)sf,&comm);
44: PetscMPIIntCast(sf->nroots,&sendcount);
45: PetscSFLinkGetMPIBuffersAndRequests(sf,link,PETSCSF_../../../../../..2LEAF,&rootbuf,&leafbuf,&req,NULL);
46: PetscSFLinkSyncStreamBeforeCallMPI(sf,link,PETSCSF_../../../../../..2LEAF);
47: MPIU_Iallgather(rootbuf,sendcount,unit,leafbuf,sendcount,unit,comm,req);
48: return 0;
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;
61: PetscSFLinkCreate(sf,unit,rootmtype,rootdata,leafmtype,leafdata,op,PETSCSF_REDUCE,&link);
62: if (op == MPI_REPLACE) {
63: /* REPLACE is only meaningful when all processes have the same leafdata to reduce. Therefore copy from local leafdata is fine */
64: PetscLayoutGetRange(sf->map,&rstart,NULL);
65: (*link->Memcpy)(link,rootmtype,rootdata,leafmtype,(const char*)leafdata+(size_t)rstart*link->unitbytes,(size_t)sf->nroots*link->unitbytes);
66: if (PetscMemTypeDevice(leafmtype) && PetscMemTypeHost(rootmtype)) (*link->SyncStream)(link); /* Sync the device to host memcpy */
67: } else {
68: PetscObjectGetComm((PetscObject)sf,&comm);
69: MPI_Comm_rank(comm,&rank);
70: PetscSFLinkPackLeafData(sf,link,PETSCSF_REMOTE,leafdata);
71: PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(sf,link,PETSC_TRUE/* device2host before sending */);
72: PetscSFLinkGetMPIBuffersAndRequests(sf,link,PETSCSF_LEAF2../../../../../..,&rootbuf,&leafbuf,&req,NULL);
73: PetscMPIIntCast(dat->rootbuflen[PETSCSF_REMOTE],&recvcount);
74: if (rank == 0 && !link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi]) {
75: PetscSFMalloc(sf,link->leafmtype_mpi,sf->leafbuflen[PETSCSF_REMOTE]*link->unitbytes,(void**)&link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi]);
76: }
77: if (rank == 0 && link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi] == leafbuf) leafbuf = MPI_IN_PLACE;
78: PetscMPIIntCast(sf->nleaves*link->bs,&count);
79: PetscSFLinkSyncStreamBeforeCallMPI(sf,link,PETSCSF_LEAF2../../../../../..);
80: MPI_Reduce(leafbuf,link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi],count,link->basicunit,op,0,comm); /* Must do reduce with MPI builltin datatype basicunit */
81: MPIU_Iscatter(link->leafbuf_alloc[PETSCSF_REMOTE][link->leafmtype_mpi],recvcount,unit,rootbuf,recvcount,unit,0/*rank 0*/,comm,req);
82: }
83: return 0;
84: }
86: static PetscErrorCode PetscSFBcastToZero_Allgather(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,const void *rootdata,PetscMemType leafmtype,void *leafdata)
87: {
88: PetscSFLink link;
89: PetscMPIInt rank;
91: PetscSFBcastBegin_Gather(sf,unit,rootmtype,rootdata,leafmtype,leafdata,MPI_REPLACE);
92: PetscSFLinkGetInUse(sf,unit,rootdata,leafdata,PETSC_OWN_POINTER,&link);
93: PetscSFLinkFinishCommunication(sf,link,PETSCSF_../../../../../..2LEAF);
94: MPI_Comm_rank(PetscObjectComm((PetscObject)sf),&rank);
95: if (rank == 0 && PetscMemTypeDevice(leafmtype) && !sf->use_gpu_aware_mpi) {
96: (*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,leafdata,PETSC_MEMTYPE_HOST,link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST],sf->leafbuflen[PETSCSF_REMOTE]*link->unitbytes);
97: }
98: PetscSFLinkReclaim(sf,&link);
99: return 0;
100: }
102: PETSC_INTERN PetscErrorCode PetscSFCreate_Allgather(PetscSF sf)
103: {
104: PetscSF_Allgather *dat = (PetscSF_Allgather*)sf->data;
106: sf->ops->BcastEnd = PetscSFBcastEnd_Basic;
107: sf->ops->ReduceEnd = PetscSFReduceEnd_Allgatherv;
109: /* Inherit from Allgatherv */
110: sf->ops->Reset = PetscSFReset_Allgatherv;
111: sf->ops->Destroy = PetscSFDestroy_Allgatherv;
112: sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Allgatherv;
113: sf->ops->FetchAndOpEnd = PetscSFFetchAndOpEnd_Allgatherv;
114: sf->ops->GetRootRanks = PetscSFGetRootRanks_Allgatherv;
115: sf->ops->CreateLocalSF = PetscSFCreateLocalSF_Allgatherv;
116: sf->ops->GetGraph = PetscSFGetGraph_Allgatherv;
117: sf->ops->GetLeafRanks = PetscSFGetLeafRanks_Allgatherv;
119: /* Allgather stuff */
120: sf->ops->SetUp = PetscSFSetUp_Allgather;
121: sf->ops->BcastBegin = PetscSFBcastBegin_Allgather;
122: sf->ops->ReduceBegin = PetscSFReduceBegin_Allgather;
123: sf->ops->BcastToZero = PetscSFBcastToZero_Allgather;
125: PetscNewLog(sf,&dat);
126: sf->data = (void*)dat;
127: return 0;
128: }