xref: /petsc/src/vec/is/sf/impls/basic/sfpack.h (revision a69119a591a03a9d906b29c0a4e9802e4d7c9795)
1 #if !defined(__SFPACK_H)
2 #define __SFPACK_H
3 
4 #include <../src/vec/is/sf/impls/basic/sfbasic.h>
5 #if defined(PETSC_HAVE_CUDA)
6 #include <petscdevice.h>
7 typedef cudaStream_t cupmStream_t;
8 typedef cudaEvent_t  cupmEvent_t;
9 #endif
10 
11 #if defined(PETSC_HAVE_HIP)
12 #include <petscdevice.h>
13 typedef hipStream_t cupmStream_t;
14 typedef hipEvent_t  cupmEvent_t;
15 #endif
16 
17 /* In terms of function overloading, long long int is a different type than int64_t, which PetscInt might be defined to.
18    We perfer long long int over PetscInt (int64_t), since CUDA atomics are built around (unsigned) long long int.
19  */
20 typedef long long int          llint;
21 typedef unsigned long long int ullint;
22 
23 /* We separate SF communications for SFBasic and SFNeighbor in two parts: local (self,intra-rank) and remote (inter-rank) */
24 typedef enum {
25   PETSCSF_LOCAL = 0,
26   PETSCSF_REMOTE
27 } PetscSFScope;
28 
29 /* Optimizations in packing & unpacking for destination ranks.
30 
31   Suppose there are m indices stored in idx[], and two addresses u, p. We want to do packing:
32      p[i] = u[idx[i]], for i in [0,m)
33 
34   Indices are associated with n ranks and each rank's indices are stored consecutively in idx[].
35   We go through indices for each rank and see if they are indices of a 3D submatrix of size [dx,dy,dz] in
36   a parent matrix of size [X,Y,Z], with the submatrix's first index being <start>.
37 
38   E.g., for indices 1,2,3, 6,7,8, 11,12,13, the submatrix size is [3,3,1] with start=1, and the parent matrix's size
39   is [5,3,1]. For simplicity, if any destination rank does not have this pattern, we give up the optimization.
40 
41   Note before using this per-rank optimization, one should check leafcontig[], rootcontig[], which say
42   indices in whole are contiguous, and therefore much more useful than this one when true.
43  */
44 struct _n_PetscSFPackOpt {
45   PetscInt *array;        /* [7*n+2] Memory pool for other fields in this struct. Used to easily copy this struct to GPU */
46   PetscInt  n;            /* Number of destination ranks */
47   PetscInt *offset;       /* [n+1] Offsets of indices for each rank. offset[0]=0, offset[i+1]=offset[i]+dx[i]*dy[i]*dz[i] */
48   PetscInt *start;        /* [n] First index */
49   PetscInt *dx, *dy, *dz; /* [n] Lengths of the submatrix in X, Y, Z dimension. */
50   PetscInt *X, *Y;        /* [n] Lengths of the outer matrix in X, Y. We do not care Z. */
51 };
52 
53 /* An abstract class that defines a communication link, which includes how to pack/unpack data and send/recv buffers
54  */
55 struct _n_PetscSFLink {
56   PetscErrorCode (*Memcpy)(PetscSFLink, PetscMemType, void *, PetscMemType, const void *, size_t); /* Async device memcopy might use stream in the link */
57   PetscErrorCode (*PrePack)(PetscSF, PetscSFLink, PetscSFDirection);
58   PetscErrorCode (*PostUnpack)(PetscSF, PetscSFLink, PetscSFDirection);
59   PetscErrorCode (*StartCommunication)(PetscSF, PetscSFLink, PetscSFDirection);
60   PetscErrorCode (*FinishCommunication)(PetscSF, PetscSFLink, PetscSFDirection);
61   PetscErrorCode (*SyncDevice)(PetscSFLink);
62   PetscErrorCode (*SyncStream)(PetscSFLink);
63   PetscErrorCode (*Destroy)(PetscSF, PetscSFLink);
64 
65   PetscErrorCode (*BuildDependenceBegin)(PetscSF, PetscSFLink, PetscSFDirection);
66   PetscErrorCode (*BuildDependenceEnd)(PetscSF, PetscSFLink, PetscSFDirection);
67 
68   PetscErrorCode (*h_Pack)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *);
69   PetscErrorCode (*h_UnpackAndInsert)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
70   PetscErrorCode (*h_UnpackAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
71   PetscErrorCode (*h_UnpackAndMin)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
72   PetscErrorCode (*h_UnpackAndMax)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
73   PetscErrorCode (*h_UnpackAndMinloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
74   PetscErrorCode (*h_UnpackAndMaxloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
75   PetscErrorCode (*h_UnpackAndMult)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
76   PetscErrorCode (*h_UnpackAndLAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
77   PetscErrorCode (*h_UnpackAndBAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
78   PetscErrorCode (*h_UnpackAndLOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
79   PetscErrorCode (*h_UnpackAndBOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
80   PetscErrorCode (*h_UnpackAndLXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
81   PetscErrorCode (*h_UnpackAndBXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
82   PetscErrorCode (*h_FetchAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, void *);
83 
84   PetscErrorCode (*h_ScatterAndInsert)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
85   PetscErrorCode (*h_ScatterAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
86   PetscErrorCode (*h_ScatterAndMin)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
87   PetscErrorCode (*h_ScatterAndMax)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
88   PetscErrorCode (*h_ScatterAndMinloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
89   PetscErrorCode (*h_ScatterAndMaxloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
90   PetscErrorCode (*h_ScatterAndMult)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
91   PetscErrorCode (*h_ScatterAndLAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
92   PetscErrorCode (*h_ScatterAndBAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
93   PetscErrorCode (*h_ScatterAndLOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
94   PetscErrorCode (*h_ScatterAndBOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
95   PetscErrorCode (*h_ScatterAndLXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
96   PetscErrorCode (*h_ScatterAndBXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
97 
98   PetscErrorCode (*h_FetchAndAddLocal)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *);
99 
100   PetscBool deviceinited; /* Are device related fields initialized? */
101 #if defined(PETSC_HAVE_DEVICE)
102   /* These fields are lazily initialized in a sense that only when device pointers are passed to an SF, the SF
103      will set them, otherwise it just leaves them alone. Packing routines using regular ops when there are no data race chances.
104   */
105   PetscErrorCode (*d_Pack)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *);
106   PetscErrorCode (*d_UnpackAndInsert)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
107   PetscErrorCode (*d_UnpackAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
108   PetscErrorCode (*d_UnpackAndMin)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
109   PetscErrorCode (*d_UnpackAndMax)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
110   PetscErrorCode (*d_UnpackAndMinloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
111   PetscErrorCode (*d_UnpackAndMaxloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
112   PetscErrorCode (*d_UnpackAndMult)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
113   PetscErrorCode (*d_UnpackAndLAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
114   PetscErrorCode (*d_UnpackAndBAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
115   PetscErrorCode (*d_UnpackAndLOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
116   PetscErrorCode (*d_UnpackAndBOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
117   PetscErrorCode (*d_UnpackAndLXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
118   PetscErrorCode (*d_UnpackAndBXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
119   PetscErrorCode (*d_FetchAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, void *);
120 
121   PetscErrorCode (*d_ScatterAndInsert)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
122   PetscErrorCode (*d_ScatterAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
123   PetscErrorCode (*d_ScatterAndMin)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
124   PetscErrorCode (*d_ScatterAndMax)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
125   PetscErrorCode (*d_ScatterAndMinloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
126   PetscErrorCode (*d_ScatterAndMaxloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
127   PetscErrorCode (*d_ScatterAndMult)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
128   PetscErrorCode (*d_ScatterAndLAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
129   PetscErrorCode (*d_ScatterAndBAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
130   PetscErrorCode (*d_ScatterAndLOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
131   PetscErrorCode (*d_ScatterAndBOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
132   PetscErrorCode (*d_ScatterAndLXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
133   PetscErrorCode (*d_ScatterAndBXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
134   PetscErrorCode (*d_FetchAndAddLocal)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *);
135 
136   /* Packing routines using atomics when there are data race chances */
137   PetscErrorCode (*da_UnpackAndInsert)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
138   PetscErrorCode (*da_UnpackAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
139   PetscErrorCode (*da_UnpackAndMin)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
140   PetscErrorCode (*da_UnpackAndMax)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
141   PetscErrorCode (*da_UnpackAndMinloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
142   PetscErrorCode (*da_UnpackAndMaxloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
143   PetscErrorCode (*da_UnpackAndMult)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
144   PetscErrorCode (*da_UnpackAndLAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
145   PetscErrorCode (*da_UnpackAndBAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
146   PetscErrorCode (*da_UnpackAndLOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
147   PetscErrorCode (*da_UnpackAndBOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
148   PetscErrorCode (*da_UnpackAndLXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
149   PetscErrorCode (*da_UnpackAndBXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *);
150   PetscErrorCode (*da_FetchAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, void *);
151 
152   PetscErrorCode (*da_ScatterAndInsert)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
153   PetscErrorCode (*da_ScatterAndAdd)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
154   PetscErrorCode (*da_ScatterAndMin)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
155   PetscErrorCode (*da_ScatterAndMax)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
156   PetscErrorCode (*da_ScatterAndMinloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
157   PetscErrorCode (*da_ScatterAndMaxloc)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
158   PetscErrorCode (*da_ScatterAndMult)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
159   PetscErrorCode (*da_ScatterAndLAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
160   PetscErrorCode (*da_ScatterAndBAND)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
161   PetscErrorCode (*da_ScatterAndLOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
162   PetscErrorCode (*da_ScatterAndBOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
163   PetscErrorCode (*da_ScatterAndLXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
164   PetscErrorCode (*da_ScatterAndBXOR)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *);
165   PetscErrorCode (*da_FetchAndAddLocal)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *);
166 #if defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
167   PetscInt     maxResidentThreadsPerGPU; /* It is a copy from SF for convenience */
168   cupmStream_t stream;                   /* stream on which input/output root/leafdata is computed on (default is PetscDefaultCudaStream) */
169 #endif
170 #endif
171   PetscMPIInt  tag;                  /* Each link has a tag so we can perform multiple SF ops at the same time */
172   MPI_Datatype unit;                 /* The MPI datatype this PetscSFLink is built for */
173   MPI_Datatype basicunit;            /* unit is made of MPI builtin dataype basicunit */
174   PetscBool    isbuiltin;            /* Is unit an MPI/PETSc builtin datatype? If it is true, then bs=1 and basicunit is equivalent to unit */
175   size_t       unitbytes;            /* Number of bytes in a unit */
176   PetscInt     bs;                   /* Number of basic units in a unit */
177   const void  *rootdata, *leafdata;  /* rootdata and leafdata the link is working on. They are used as keys for pending links. */
178   PetscMemType rootmtype, leafmtype; /* root/leafdata's memory type */
179 
180   /* For local and remote communication */
181   PetscMemType rootmtype_mpi, leafmtype_mpi;   /* Mtypes of buffers passed to MPI. If use_gpu_aware_mpi, they are same as root/leafmtype. Otherwise they are PETSC_MEMTYPE_HOST */
182   PetscBool    rootdirect[2], leafdirect[2];   /* Can root/leafdata be directly passed to SF (i.e., without buffering). In layout of [PETSCSF_LOCAL/REMOTE]. See more in PetscSFLinkCreate() */
183   PetscInt     rootdirect_mpi, leafdirect_mpi; /* Can root/leafdata for remote be directly passed to MPI? 1: yes, 0: no. See more in PetscSFLinkCreate() */
184   const void  *rootdatadirect[2][2];           /* The root/leafdata used to init root/leaf requests, in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE]. */
185   const void  *leafdatadirect[2][2];           /* ... We need them to look up links when root/leafdirect_mpi are true */
186   char        *rootbuf[2][2];                  /* Buffers for packed roots, in layout of [PETSCSF_LOCAL/REMOTE][PETSC_MEMTYPE]. PETSCSF_LOCAL does not need MPI, .. */
187                                                /* .. but in case rootmtype is different from leafmtype, we still need to pack local roots and then copy them to memory of leafmtype */
188   char        *rootbuf_alloc[2][2];            /* Log memory allocated by petsc. We need it since rootbuf[][] may point to rootdata given by user */
189   char        *leafbuf[2][2];                  /* Buffers for packed leaves, in layout of [PETSCSF_LOCAL/REMOTE][PETSC_MEMTYPE] */
190   char        *leafbuf_alloc[2][2];
191   MPI_Request *rootreqs[2][2][2];       /* Root requests in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][rootdirect_mpi] */
192   MPI_Request *leafreqs[2][2][2];       /* Leaf requests in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][leafdirect_mpi] */
193   PetscBool    rootreqsinited[2][2][2]; /* Are root requests initialized? Also in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][rootdirect_mpi]*/
194   PetscBool    leafreqsinited[2][2][2]; /* Are leaf requests initialized? Also in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][leafdirect_mpi]*/
195   MPI_Request *reqs;                    /* An array of length (nrootreqs+nleafreqs)*8. Pointers in rootreqs[][][] and leafreqs[][][] point here */
196   PetscSFLink  next;
197 
198   PetscBool use_nvshmem; /* Does this link use nvshem (vs. MPI) for communication? */
199 #if defined(PETSC_HAVE_NVSHMEM)
200   cupmEvent_t  dataReady;        /* Events to mark readiness of root/leafdata */
201   cupmEvent_t  endRemoteComm;    /* Events to mark end of local/remote communication */
202   cupmStream_t remoteCommStream; /* Streams for remote (i.e., inter-rank) communication */
203 
204   /* The buffers are allocated in device symmetric heap. Their length is the maximal length over all ranks in the comm, and therefore is the same. */
205   uint64_t *rootSendSig, *rootRecvSig; /* [max{niranks-ndiranks}], signals used when rootbuf works as send/recv buf */
206   uint64_t *leafSendSig, *leafRecvSig; /* [max{nranks-ndranks}], signals used when leafbuf works as send/recv buf */
207 #endif
208 };
209 
210 PETSC_INTERN PetscErrorCode PetscSFSetErrorOnUnsupportedOverlap(PetscSF, MPI_Datatype, const void *, const void *);
211 
212 /* Create/setup/retrieve/destroy a link */
213 PETSC_INTERN PetscErrorCode PetscSFLinkCreate(PetscSF, MPI_Datatype, PetscMemType, const void *, PetscMemType, const void *, MPI_Op, PetscSFOperation, PetscSFLink *);
214 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_Host(PetscSF, PetscSFLink, MPI_Datatype);
215 PETSC_INTERN PetscErrorCode PetscSFLinkGetInUse(PetscSF, MPI_Datatype, const void *, const void *, PetscCopyMode, PetscSFLink *);
216 PETSC_INTERN PetscErrorCode PetscSFLinkReclaim(PetscSF, PetscSFLink *);
217 PETSC_INTERN PetscErrorCode PetscSFLinkDestroy(PetscSF, PetscSFLink);
218 
219 /* Get pack/unpack function pointers from a link */
220 static inline PetscErrorCode PetscSFLinkGetPack(PetscSFLink link, PetscMemType mtype, PetscErrorCode (**Pack)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *)) {
221   PetscFunctionBegin;
222   if (PetscMemTypeHost(mtype)) *Pack = link->h_Pack;
223 #if defined(PETSC_HAVE_DEVICE)
224   else *Pack = link->d_Pack;
225 #endif
226   PetscFunctionReturn(0);
227 }
228 
229 PETSC_INTERN PetscErrorCode PetscSFLinkGetUnpackAndOp(PetscSFLink, PetscMemType, MPI_Op, PetscBool, PetscErrorCode (**UnpackAndOp)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, const void *));
230 PETSC_INTERN PetscErrorCode PetscSFLinkGetFetchAndOp(PetscSFLink, PetscMemType, MPI_Op, PetscBool, PetscErrorCode (**FetchAndOp)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, void *));
231 PETSC_INTERN PetscErrorCode PetscSFLinkGetScatterAndOp(PetscSFLink, PetscMemType, MPI_Op, PetscBool, PetscErrorCode (**ScatterAndOp)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, PetscInt, PetscSFPackOpt, const PetscInt *, void *));
232 PETSC_INTERN PetscErrorCode PetscSFLinkGetFetchAndOpLocal(PetscSFLink, PetscMemType, MPI_Op, PetscBool, PetscErrorCode (**FetchAndOpLocal)(PetscSFLink, PetscInt, PetscInt, PetscSFPackOpt, const PetscInt *, void *, PetscInt, PetscSFPackOpt, const PetscInt *, const void *, void *));
233 PETSC_INTERN PetscErrorCode PetscSFLinkGetMPIBuffersAndRequests(PetscSF, PetscSFLink, PetscSFDirection, void **, void **, MPI_Request **, MPI_Request **);
234 
235 /* Do Pack/Unpack/Fetch/Scatter with the link */
236 PETSC_INTERN PetscErrorCode PetscSFLinkPackRootData(PetscSF, PetscSFLink, PetscSFScope, const void *);
237 PETSC_INTERN PetscErrorCode PetscSFLinkPackLeafData(PetscSF, PetscSFLink, PetscSFScope, const void *);
238 PETSC_INTERN PetscErrorCode PetscSFLinkUnpackRootData(PetscSF, PetscSFLink, PetscSFScope, void *, MPI_Op);
239 PETSC_INTERN PetscErrorCode PetscSFLinkUnpackLeafData(PetscSF, PetscSFLink, PetscSFScope, void *, MPI_Op);
240 PETSC_INTERN PetscErrorCode PetscSFLinkFetchAndOpRemote(PetscSF, PetscSFLink, void *, MPI_Op);
241 
242 PETSC_INTERN PetscErrorCode PetscSFLinkScatterLocal(PetscSF, PetscSFLink, PetscSFDirection, void *, void *, MPI_Op);
243 PETSC_INTERN PetscErrorCode PetscSFLinkFetchAndOpLocal(PetscSF, PetscSFLink, void *, const void *, void *, MPI_Op);
244 
245 PETSC_INTERN PetscErrorCode PetscSFSetUpPackFields(PetscSF);
246 PETSC_INTERN PetscErrorCode PetscSFResetPackFields(PetscSF);
247 PETSC_INTERN PetscErrorCode PetscSFLinkCreate_MPI(PetscSF, MPI_Datatype, PetscMemType, const void *, PetscMemType, const void *, MPI_Op, PetscSFOperation, PetscSFLink *);
248 
249 #if defined(PETSC_HAVE_CUDA)
250 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_CUDA(PetscSF, PetscSFLink, MPI_Datatype);
251 #endif
252 
253 #if defined(PETSC_HAVE_HIP)
254 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_HIP(PetscSF, PetscSFLink, MPI_Datatype);
255 #endif
256 
257 #if defined(PETSC_HAVE_KOKKOS)
258 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_Kokkos(PetscSF, PetscSFLink, MPI_Datatype);
259 #endif
260 
261 #if defined(PETSC_HAVE_NVSHMEM)
262 PETSC_INTERN PetscErrorCode PetscSFLinkCreate_NVSHMEM(PetscSF, MPI_Datatype, PetscMemType, const void *, PetscMemType, const void *, MPI_Op, PetscSFOperation, PetscSFLink *);
263 PETSC_INTERN PetscErrorCode PetscSFLinkNvshmemCheck(PetscSF, PetscMemType, const void *, PetscMemType, const void *, PetscBool *);
264 #endif
265 
266 static inline PetscErrorCode PetscSFLinkStartCommunication(PetscSF sf, PetscSFLink link, PetscSFDirection direction) {
267   PetscFunctionBegin;
268   if (link->StartCommunication) PetscCall((*link->StartCommunication)(sf, link, direction));
269   PetscFunctionReturn(0);
270 }
271 
272 static inline PetscErrorCode PetscSFLinkFinishCommunication(PetscSF sf, PetscSFLink link, PetscSFDirection direction) {
273   PetscFunctionBegin;
274   if (link->FinishCommunication) PetscCall((*link->FinishCommunication)(sf, link, direction));
275   PetscFunctionReturn(0);
276 }
277 
278 /* A set of helper routines for Pack/Unpack/Scatter on GPUs */
279 #if defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP) || defined(PETSC_HAVE_SYCL)
280 /* PetscSFLinkCopyXxxxBufferInCaseNotUseGpuAwareMPI routines are simple: if not use_gpu_aware_mpi, we need
281    to copy the buffer from GPU to CPU before MPI calls, and from CPU to GPU after MPI calls.
282 */
283 static inline PetscErrorCode PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(PetscSF sf, PetscSFLink link, PetscBool device2host) {
284   PetscSF_Basic *bas = (PetscSF_Basic *)sf->data;
285 
286   PetscFunctionBegin;
287   /* rootdata is on device but we use regular MPI for communication */
288   if (PetscMemTypeDevice(link->rootmtype) && PetscMemTypeHost(link->rootmtype_mpi) && bas->rootbuflen[PETSCSF_REMOTE]) {
289     void  *h_buf = link->rootbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST];
290     void  *d_buf = link->rootbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_DEVICE];
291     size_t count = bas->rootbuflen[PETSCSF_REMOTE] * link->unitbytes;
292     if (device2host) {
293       PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_HOST, h_buf, PETSC_MEMTYPE_DEVICE, d_buf, count));
294       PetscCall(PetscLogGpuToCpu(count));
295     } else {
296       PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, d_buf, PETSC_MEMTYPE_HOST, h_buf, count));
297       PetscCall(PetscLogCpuToGpu(count));
298     }
299   }
300   PetscFunctionReturn(0);
301 }
302 
303 static inline PetscErrorCode PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(PetscSF sf, PetscSFLink link, PetscBool device2host) {
304   PetscFunctionBegin;
305   if (PetscMemTypeDevice(link->leafmtype) && PetscMemTypeHost(link->leafmtype_mpi) && sf->leafbuflen[PETSCSF_REMOTE]) {
306     void  *h_buf = link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST];
307     void  *d_buf = link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_DEVICE];
308     size_t count = sf->leafbuflen[PETSCSF_REMOTE] * link->unitbytes;
309     if (device2host) {
310       PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_HOST, h_buf, PETSC_MEMTYPE_DEVICE, d_buf, count));
311       PetscCall(PetscLogGpuToCpu(count));
312     } else {
313       PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, d_buf, PETSC_MEMTYPE_HOST, h_buf, count));
314       PetscCall(PetscLogCpuToGpu(count));
315     }
316   }
317   PetscFunctionReturn(0);
318 }
319 
320 /* Make sure root/leafbuf for the remote is ready for MPI */
321 static inline PetscErrorCode PetscSFLinkSyncStreamBeforeCallMPI(PetscSF sf, PetscSFLink link, PetscSFDirection direction) {
322   PetscSF_Basic *bas;
323   PetscInt       buflen;
324   PetscMemType   mtype;
325 
326   PetscFunctionBegin;
327   if (direction == PETSCSF_ROOT2LEAF) {
328     bas    = (PetscSF_Basic *)sf->data;
329     mtype  = link->rootmtype;
330     buflen = bas->rootbuflen[PETSCSF_REMOTE];
331   } else {
332     mtype  = link->leafmtype;
333     buflen = sf->leafbuflen[PETSCSF_REMOTE];
334   }
335 
336   if (PetscMemTypeDevice(mtype) && buflen) PetscCall((*link->SyncStream)(link));
337   PetscFunctionReturn(0);
338 }
339 #else /* Host only */
340 #define PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(a, b, c) 0
341 #define PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(a, b, c) 0
342 #define PetscSFLinkSyncStreamBeforeCallMPI(a, b, c)               0
343 #endif
344 
345 /* Get root indices used for pack/unpack
346 
347 Input arguments:
348   +sf    - StarForest
349   .link  - The link, which provides the stream for the async memcpy (In SF, we make all GPU operations asynchronous to avoid unexpected pipeline stalls)
350   .mtype - In what type of memory? (PETSC_MEMTYPE_DEVICE or PETSC_MEMTYPE_HOST)
351   -scope - Which part of the indices? (PETSCSF_LOCAL or PETSCSF_REMOTE)
352 
353  Output arguments:
354   +count   - Count of indices
355   .start   - The first index (only useful when indices is NULL)
356   .opt     - Packing optimizations
357   -indices - Indices of roots for pack/unpack. NULL means indices are contiguous
358  */
359 static inline PetscErrorCode PetscSFLinkGetRootPackOptAndIndices(PetscSF sf, PetscSFLink link, PetscMemType mtype, PetscSFScope scope, PetscInt *count, PetscInt *start, PetscSFPackOpt *opt, const PetscInt **indices) {
360   PetscSF_Basic *bas = (PetscSF_Basic *)sf->data;
361   PetscInt       offset;
362 
363   PetscFunctionBegin;
364   *count   = bas->rootbuflen[scope];
365   *start   = bas->rootstart[scope];
366   *opt     = NULL;
367   *indices = NULL;
368 
369   /* We have these rules:
370     1) opt == NULL && indices == NULL ==> indices are contiguous.
371     2) opt != NULL ==> indices are in 3D but not contiguous. On host, indices != NULL since indices are already available and we do not
372        want to enforce all operations to use opt; but on device, indices = NULL since we do not want to copy indices to device.
373   */
374   if (!bas->rootcontig[scope]) {
375     offset = (scope == PETSCSF_LOCAL) ? 0 : bas->ioffset[bas->ndiranks];
376     if (PetscMemTypeHost(mtype)) {
377       *opt     = bas->rootpackopt[scope];
378       *indices = bas->irootloc + offset;
379     } else {
380       size_t size;
381       if (bas->rootpackopt[scope]) {
382         if (!bas->rootpackopt_d[scope]) {
383           PetscCall(PetscMalloc1(1, &bas->rootpackopt_d[scope]));
384           PetscCall(PetscArraycpy(bas->rootpackopt_d[scope], bas->rootpackopt[scope], 1)); /* Make pointers in bas->rootpackopt_d[] still work on host */
385           size = (bas->rootpackopt[scope]->n * 7 + 2) * sizeof(PetscInt);                  /* See comments at struct _n_PetscSFPackOpt*/
386           PetscCall(PetscSFMalloc(sf, PETSC_MEMTYPE_DEVICE, size, (void **)&bas->rootpackopt_d[scope]->array));
387           PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, bas->rootpackopt_d[scope]->array, PETSC_MEMTYPE_HOST, bas->rootpackopt[scope]->array, size));
388         }
389         *opt = bas->rootpackopt_d[scope];
390       } else { /* On device, we only provide indices when there is no optimization. We're reluctant to copy indices to device. */
391         if (!bas->irootloc_d[scope]) {
392           size = bas->rootbuflen[scope] * sizeof(PetscInt);
393           PetscCall(PetscSFMalloc(sf, PETSC_MEMTYPE_DEVICE, size, (void **)&bas->irootloc_d[scope]));
394           PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, bas->irootloc_d[scope], PETSC_MEMTYPE_HOST, bas->irootloc + offset, size));
395         }
396         *indices = bas->irootloc_d[scope];
397       }
398     }
399   }
400   PetscFunctionReturn(0);
401 }
402 
403 /* Get leaf indices used for pack/unpack
404 
405   See also PetscSFLinkGetRootPackOptAndIndices()
406  */
407 static inline PetscErrorCode PetscSFLinkGetLeafPackOptAndIndices(PetscSF sf, PetscSFLink link, PetscMemType mtype, PetscSFScope scope, PetscInt *count, PetscInt *start, PetscSFPackOpt *opt, const PetscInt **indices) {
408   PetscInt offset;
409 
410   PetscFunctionBegin;
411   *count   = sf->leafbuflen[scope];
412   *start   = sf->leafstart[scope];
413   *opt     = NULL;
414   *indices = NULL;
415   if (!sf->leafcontig[scope]) {
416     offset = (scope == PETSCSF_LOCAL) ? 0 : sf->roffset[sf->ndranks];
417     if (PetscMemTypeHost(mtype)) {
418       *opt     = sf->leafpackopt[scope];
419       *indices = sf->rmine + offset;
420     } else {
421       size_t size;
422       if (sf->leafpackopt[scope]) {
423         if (!sf->leafpackopt_d[scope]) {
424           PetscCall(PetscMalloc1(1, &sf->leafpackopt_d[scope]));
425           PetscCall(PetscArraycpy(sf->leafpackopt_d[scope], sf->leafpackopt[scope], 1));
426           size = (sf->leafpackopt[scope]->n * 7 + 2) * sizeof(PetscInt);                                       /* See comments at struct _n_PetscSFPackOpt*/
427           PetscCall(PetscSFMalloc(sf, PETSC_MEMTYPE_DEVICE, size, (void **)&sf->leafpackopt_d[scope]->array)); /* Change ->array to a device pointer */
428           PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, sf->leafpackopt_d[scope]->array, PETSC_MEMTYPE_HOST, sf->leafpackopt[scope]->array, size));
429         }
430         *opt = sf->leafpackopt_d[scope];
431       } else {
432         if (!sf->rmine_d[scope]) {
433           size = sf->leafbuflen[scope] * sizeof(PetscInt);
434           PetscCall(PetscSFMalloc(sf, PETSC_MEMTYPE_DEVICE, size, (void **)&sf->rmine_d[scope]));
435           PetscCall((*link->Memcpy)(link, PETSC_MEMTYPE_DEVICE, sf->rmine_d[scope], PETSC_MEMTYPE_HOST, sf->rmine + offset, size));
436         }
437         *indices = sf->rmine_d[scope];
438       }
439     }
440   }
441   PetscFunctionReturn(0);
442 }
443 #endif
444