xref: /petsc/src/vec/is/sf/impls/basic/sfpack.h (revision f97672e55eacc8688507b9471cd7ec2664d7f203)
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 {PETSCSF_LOCAL=0, PETSCSF_REMOTE} PetscSFScope;
25 
26 /* Optimizations in packing & unpacking for destination ranks.
27 
28   Suppose there are m indices stored in idx[], and two addresses u, p. We want to do packing:
29      p[i] = u[idx[i]], for i in [0,m)
30 
31   Indices are associated with n ranks and each rank's indices are stored consecutively in idx[].
32   We go through indices for each rank and see if they are indices of a 3D submatrix of size [dx,dy,dz] in
33   a parent matrix of size [X,Y,Z], with the submatrix's first index being <start>.
34 
35   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
36   is [5,3,1]. For simplicity, if any destination rank does not have this pattern, we give up the optimization.
37 
38   Note before using this per-rank optimization, one should check leafcontig[], rootcontig[], which say
39   indices in whole are contiguous, and therefore much more useful than this one when true.
40  */
41 struct _n_PetscSFPackOpt {
42   PetscInt       *array;      /* [7*n+2] Memory pool for other fields in this struct. Used to easily copy this struct to GPU */
43   PetscInt       n;           /* Number of destination ranks */
44   PetscInt       *offset;     /* [n+1] Offsets of indices for each rank. offset[0]=0, offset[i+1]=offset[i]+dx[i]*dy[i]*dz[i] */
45   PetscInt       *start;      /* [n] First index */
46   PetscInt       *dx,*dy,*dz; /* [n] Lengths of the submatrix in X, Y, Z dimension. */
47   PetscInt       *X,*Y;       /* [n] Lengths of the outer matrix in X, Y. We do not care Z. */
48 };
49 
50 /* An abstract class that defines a communication link, which includes how to pack/unpack data and send/recv buffers
51  */
52 struct _n_PetscSFLink {
53   PetscErrorCode (*Memcpy)              (PetscSFLink,PetscMemType,void*,PetscMemType,const void*,size_t); /* Async device memcopy might use stream in the link */
54   PetscErrorCode (*PrePack)             (PetscSF,PetscSFLink,PetscSFDirection);
55   PetscErrorCode (*PostUnpack)          (PetscSF,PetscSFLink,PetscSFDirection);
56   PetscErrorCode (*StartCommunication)  (PetscSF,PetscSFLink,PetscSFDirection);
57   PetscErrorCode (*FinishCommunication) (PetscSF,PetscSFLink,PetscSFDirection);
58   PetscErrorCode (*SyncDevice)          (PetscSFLink);
59   PetscErrorCode (*SyncStream)          (PetscSFLink);
60   PetscErrorCode (*Destroy)             (PetscSF,PetscSFLink);
61 
62   PetscErrorCode (*BuildDependenceBegin)(PetscSF,PetscSFLink,PetscSFDirection);
63   PetscErrorCode (*BuildDependenceEnd)  (PetscSF,PetscSFLink,PetscSFDirection);
64 
65   PetscErrorCode (*h_Pack)            (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,void*);
66   PetscErrorCode (*h_UnpackAndInsert) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
67   PetscErrorCode (*h_UnpackAndAdd)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
68   PetscErrorCode (*h_UnpackAndMin)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
69   PetscErrorCode (*h_UnpackAndMax)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
70   PetscErrorCode (*h_UnpackAndMinloc) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
71   PetscErrorCode (*h_UnpackAndMaxloc) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
72   PetscErrorCode (*h_UnpackAndMult)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
73   PetscErrorCode (*h_UnpackAndLAND)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
74   PetscErrorCode (*h_UnpackAndBAND)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
75   PetscErrorCode (*h_UnpackAndLOR)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
76   PetscErrorCode (*h_UnpackAndBOR)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
77   PetscErrorCode (*h_UnpackAndLXOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
78   PetscErrorCode (*h_UnpackAndBXOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
79   PetscErrorCode (*h_FetchAndAdd)     (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,      void*);
80 
81   PetscErrorCode (*h_ScatterAndInsert)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
82   PetscErrorCode (*h_ScatterAndAdd)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
83   PetscErrorCode (*h_ScatterAndMin)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
84   PetscErrorCode (*h_ScatterAndMax)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
85   PetscErrorCode (*h_ScatterAndMinloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
86   PetscErrorCode (*h_ScatterAndMaxloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
87   PetscErrorCode (*h_ScatterAndMult)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
88   PetscErrorCode (*h_ScatterAndLAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
89   PetscErrorCode (*h_ScatterAndBAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
90   PetscErrorCode (*h_ScatterAndLOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
91   PetscErrorCode (*h_ScatterAndBOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
92   PetscErrorCode (*h_ScatterAndLXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
93   PetscErrorCode (*h_ScatterAndBXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
94 
95   PetscErrorCode (*h_FetchAndAddLocal)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,void*);
96 
97   PetscBool      deviceinited;        /* Are device related fields initialized? */
98 #if defined(PETSC_HAVE_DEVICE)
99   /* These fields are lazily initialized in a sense that only when device pointers are passed to an SF, the SF
100      will set them, otherwise it just leaves them alone. Packing routines using regular ops when there are no data race chances.
101   */
102   PetscErrorCode (*d_Pack)            (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,void*);
103   PetscErrorCode (*d_UnpackAndInsert) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
104   PetscErrorCode (*d_UnpackAndAdd)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
105   PetscErrorCode (*d_UnpackAndMin)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
106   PetscErrorCode (*d_UnpackAndMax)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
107   PetscErrorCode (*d_UnpackAndMinloc) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
108   PetscErrorCode (*d_UnpackAndMaxloc) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
109   PetscErrorCode (*d_UnpackAndMult)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
110   PetscErrorCode (*d_UnpackAndLAND)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
111   PetscErrorCode (*d_UnpackAndBAND)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
112   PetscErrorCode (*d_UnpackAndLOR)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
113   PetscErrorCode (*d_UnpackAndBOR)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
114   PetscErrorCode (*d_UnpackAndLXOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
115   PetscErrorCode (*d_UnpackAndBXOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
116   PetscErrorCode (*d_FetchAndAdd)     (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,      void*);
117 
118   PetscErrorCode (*d_ScatterAndInsert)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
119   PetscErrorCode (*d_ScatterAndAdd)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
120   PetscErrorCode (*d_ScatterAndMin)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
121   PetscErrorCode (*d_ScatterAndMax)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
122   PetscErrorCode (*d_ScatterAndMinloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
123   PetscErrorCode (*d_ScatterAndMaxloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
124   PetscErrorCode (*d_ScatterAndMult)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
125   PetscErrorCode (*d_ScatterAndLAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
126   PetscErrorCode (*d_ScatterAndBAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
127   PetscErrorCode (*d_ScatterAndLOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
128   PetscErrorCode (*d_ScatterAndBOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
129   PetscErrorCode (*d_ScatterAndLXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
130   PetscErrorCode (*d_ScatterAndBXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
131   PetscErrorCode (*d_FetchAndAddLocal)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,void*);
132 
133   /* Packing routines using atomics when there are data race chances */
134   PetscErrorCode (*da_UnpackAndInsert)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
135   PetscErrorCode (*da_UnpackAndAdd)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
136   PetscErrorCode (*da_UnpackAndMin)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
137   PetscErrorCode (*da_UnpackAndMax)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
138   PetscErrorCode (*da_UnpackAndMinloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
139   PetscErrorCode (*da_UnpackAndMaxloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
140   PetscErrorCode (*da_UnpackAndMult)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
141   PetscErrorCode (*da_UnpackAndLAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
142   PetscErrorCode (*da_UnpackAndBAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
143   PetscErrorCode (*da_UnpackAndLOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
144   PetscErrorCode (*da_UnpackAndBOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
145   PetscErrorCode (*da_UnpackAndLXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
146   PetscErrorCode (*da_UnpackAndBXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*);
147   PetscErrorCode (*da_FetchAndAdd)    (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,      void*);
148 
149   PetscErrorCode (*da_ScatterAndInsert)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
150   PetscErrorCode (*da_ScatterAndAdd)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
151   PetscErrorCode (*da_ScatterAndMin)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
152   PetscErrorCode (*da_ScatterAndMax)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
153   PetscErrorCode (*da_ScatterAndMinloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
154   PetscErrorCode (*da_ScatterAndMaxloc)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
155   PetscErrorCode (*da_ScatterAndMult)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
156   PetscErrorCode (*da_ScatterAndLAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
157   PetscErrorCode (*da_ScatterAndBAND)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
158   PetscErrorCode (*da_ScatterAndLOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
159   PetscErrorCode (*da_ScatterAndBOR)   (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
160   PetscErrorCode (*da_ScatterAndLXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
161   PetscErrorCode (*da_ScatterAndBXOR)  (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*);
162   PetscErrorCode (*da_FetchAndAddLocal)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,void*);
163  #if defined (PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
164   PetscInt       maxResidentThreadsPerGPU;   /* It is a copy from SF for convenience */
165   cupmStream_t   stream;                     /* stream on which input/output root/leafdata is computed on (default is PetscDefaultCudaStream) */
166  #endif
167 #endif
168   PetscMPIInt  tag;                          /* Each link has a tag so we can perform multiple SF ops at the same time */
169   MPI_Datatype unit;                         /* The MPI datatype this PetscSFLink is built for */
170   MPI_Datatype basicunit;                    /* unit is made of MPI builtin dataype basicunit */
171   PetscBool    isbuiltin;                    /* Is unit an MPI/PETSc builtin datatype? If it is true, then bs=1 and basicunit is equivalent to unit */
172   size_t       unitbytes;                    /* Number of bytes in a unit */
173   PetscInt     bs;                           /* Number of basic units in a unit */
174   const void   *rootdata,*leafdata;          /* rootdata and leafdata the link is working on. They are used as keys for pending links. */
175   PetscMemType rootmtype,leafmtype;          /* root/leafdata's memory type */
176 
177   /* For local and remote communication */
178   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 */
179   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() */
180   PetscInt     rootdirect_mpi,leafdirect_mpi;/* Can root/leafdata for remote be directly passed to MPI? 1: yes, 0: no. See more in PetscSFLinkCreate() */
181   const void   *rootdatadirect[2][2];        /* The root/leafdata used to init root/leaf requests, in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE]. */
182   const void   *leafdatadirect[2][2];        /* ... We need them to look up links when root/leafdirect_mpi are true */
183   char         *rootbuf[2][2];               /* Buffers for packed roots, in layout of [PETSCSF_LOCAL/REMOTE][PETSC_MEMTYPE]. PETSCSF_LOCAL does not need MPI, .. */
184                                              /* .. but in case rootmtype is different from leafmtype, we still need to pack local roots and then copy them to memory of leafmtype */
185   char         *rootbuf_alloc[2][2];         /* Log memory allocated by petsc. We need it since rootbuf[][] may point to rootdata given by user */
186   char         *leafbuf[2][2];               /* Buffers for packed leaves, in layout of [PETSCSF_LOCAL/REMOTE][PETSC_MEMTYPE] */
187   char         *leafbuf_alloc[2][2];
188   MPI_Request  *rootreqs[2][2][2];           /* Root requests in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][rootdirect_mpi] */
189   MPI_Request  *leafreqs[2][2][2];           /* Leaf requests in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][leafdirect_mpi] */
190   PetscBool    rootreqsinited[2][2][2];      /* Are root requests initialized? Also in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][rootdirect_mpi]*/
191   PetscBool    leafreqsinited[2][2][2];      /* Are leaf requests initialized? Also in layout of [PETSCSF_DIRECTION][PETSC_MEMTYPE][leafdirect_mpi]*/
192   MPI_Request  *reqs;                        /* An array of length (nrootreqs+nleafreqs)*8. Pointers in rootreqs[][][] and leafreqs[][][] point here */
193   PetscSFLink  next;
194 
195   PetscBool    use_nvshmem;                  /* Does this link use nvshem (vs. MPI) for communication? */
196 #if defined(PETSC_HAVE_NVSHMEM)
197   cupmEvent_t  dataReady;                    /* Events to mark readiness of root/leafdata */
198   cupmEvent_t  endRemoteComm;              /* Events to mark end of local/remote communication */
199   cupmStream_t remoteCommStream;             /* Streams for remote (i.e., inter-rank) communication */
200 
201   /* 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. */
202   uint64_t     *rootSendSig,*rootRecvSig;    /* [max{niranks-ndiranks}], signals used when rootbuf works as send/recv buf */
203   uint64_t     *leafSendSig,*leafRecvSig;    /* [max{nranks-ndranks}], signals used when leafbuf works as send/recv buf */
204 #endif
205 };
206 
207 PETSC_INTERN PetscErrorCode PetscSFSetErrorOnUnsupportedOverlap(PetscSF,MPI_Datatype,const void*,const void*);
208 
209 /* Create/setup/retrieve/destroy a link */
210 PETSC_INTERN PetscErrorCode PetscSFLinkCreate(PetscSF,MPI_Datatype,PetscMemType,const void*,PetscMemType,const void*,MPI_Op,PetscSFOperation,PetscSFLink*);
211 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_Host(PetscSF,PetscSFLink,MPI_Datatype);
212 PETSC_INTERN PetscErrorCode PetscSFLinkGetInUse(PetscSF,MPI_Datatype,const void*,const void*,PetscCopyMode,PetscSFLink*);
213 PETSC_INTERN PetscErrorCode PetscSFLinkReclaim(PetscSF,PetscSFLink*);
214 PETSC_INTERN PetscErrorCode PetscSFLinkDestroy(PetscSF,PetscSFLink);
215 
216 /* Get pack/unpack function pointers from a link */
217 static inline PetscErrorCode PetscSFLinkGetPack(PetscSFLink link,PetscMemType mtype,PetscErrorCode (**Pack)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,void*))
218 {
219   PetscFunctionBegin;
220   if (PetscMemTypeHost(mtype)) *Pack = link->h_Pack;
221 #if defined(PETSC_HAVE_DEVICE)
222   else *Pack = link->d_Pack;
223 #endif
224   PetscFunctionReturn(0);
225 }
226 
227 PETSC_INTERN PetscErrorCode PetscSFLinkGetUnpackAndOp(PetscSFLink,PetscMemType,MPI_Op,PetscBool,PetscErrorCode (**UnpackAndOp)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,const void*));
228 PETSC_INTERN PetscErrorCode PetscSFLinkGetFetchAndOp (PetscSFLink,PetscMemType,MPI_Op,PetscBool,PetscErrorCode (**FetchAndOp) (PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,void*,void*));
229 PETSC_INTERN PetscErrorCode PetscSFLinkGetScatterAndOp(PetscSFLink,PetscMemType,MPI_Op,PetscBool,PetscErrorCode (**ScatterAndOp)(PetscSFLink,PetscInt,PetscInt,PetscSFPackOpt,const PetscInt*,const void*,PetscInt,PetscSFPackOpt,const PetscInt*,void*));
230 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*));
231 PETSC_INTERN PetscErrorCode PetscSFLinkGetMPIBuffersAndRequests(PetscSF,PetscSFLink,PetscSFDirection,void**,void**,MPI_Request**,MPI_Request**);
232 
233 /* Do Pack/Unpack/Fetch/Scatter with the link */
234 PETSC_INTERN PetscErrorCode PetscSFLinkPackRootData  (PetscSF,PetscSFLink,PetscSFScope,const void*);
235 PETSC_INTERN PetscErrorCode PetscSFLinkPackLeafData  (PetscSF,PetscSFLink,PetscSFScope,const void*);
236 PETSC_INTERN PetscErrorCode PetscSFLinkUnpackRootData(PetscSF,PetscSFLink,PetscSFScope,void*,MPI_Op);
237 PETSC_INTERN PetscErrorCode PetscSFLinkUnpackLeafData(PetscSF,PetscSFLink,PetscSFScope,void*,MPI_Op);
238 PETSC_INTERN PetscErrorCode PetscSFLinkFetchAndOpRemote (PetscSF,PetscSFLink,void*,MPI_Op);
239 
240 PETSC_INTERN PetscErrorCode PetscSFLinkScatterLocal(PetscSF,PetscSFLink,PetscSFDirection,void*,void*,MPI_Op);
241 PETSC_INTERN PetscErrorCode PetscSFLinkFetchAndOpLocal(PetscSF,PetscSFLink,void*,const void*,void*,MPI_Op);
242 
243 PETSC_INTERN PetscErrorCode PetscSFSetUpPackFields(PetscSF);
244 PETSC_INTERN PetscErrorCode PetscSFResetPackFields(PetscSF);
245 PETSC_INTERN PetscErrorCode PetscSFLinkCreate_MPI(PetscSF,MPI_Datatype,PetscMemType,const void*,PetscMemType,const void*,MPI_Op,PetscSFOperation,PetscSFLink*);
246 
247 #if defined(PETSC_HAVE_CUDA)
248 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_CUDA(PetscSF,PetscSFLink,MPI_Datatype);
249 #endif
250 
251 #if defined(PETSC_HAVE_HIP)
252 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_HIP(PetscSF,PetscSFLink,MPI_Datatype);
253 #endif
254 
255 #if defined(PETSC_HAVE_KOKKOS)
256 PETSC_INTERN PetscErrorCode PetscSFLinkSetUp_Kokkos(PetscSF,PetscSFLink,MPI_Datatype);
257 #endif
258 
259 #if defined(PETSC_HAVE_NVSHMEM)
260 PETSC_INTERN PetscErrorCode PetscSFLinkCreate_NVSHMEM(PetscSF,MPI_Datatype,PetscMemType,const void*,PetscMemType,const void*,MPI_Op,PetscSFOperation,PetscSFLink*);
261 PETSC_INTERN PetscErrorCode PetscSFLinkNvshmemCheck(PetscSF,PetscMemType,const void*,PetscMemType,const void*,PetscBool*);
262 #endif
263 
264 static inline PetscErrorCode PetscSFLinkStartCommunication(PetscSF sf,PetscSFLink link,PetscSFDirection direction)
265 {
266   PetscFunctionBegin;
267   if (link->StartCommunication) PetscCall((*link->StartCommunication)(sf,link,direction));
268   PetscFunctionReturn(0);
269 }
270 
271 static inline PetscErrorCode PetscSFLinkFinishCommunication(PetscSF sf,PetscSFLink link,PetscSFDirection direction)
272 {
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 {
285   PetscSF_Basic  *bas = (PetscSF_Basic*)sf->data;
286 
287   PetscFunctionBegin;
288   /* rootdata is on device but we use regular MPI for communication */
289   if (PetscMemTypeDevice(link->rootmtype) && PetscMemTypeHost(link->rootmtype_mpi) && bas->rootbuflen[PETSCSF_REMOTE]) {
290     void  *h_buf = link->rootbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST];
291     void  *d_buf = link->rootbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_DEVICE];
292     size_t count = bas->rootbuflen[PETSCSF_REMOTE]*link->unitbytes;
293     if (device2host) {
294       PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_HOST,h_buf,PETSC_MEMTYPE_DEVICE,d_buf,count));
295       PetscCall(PetscLogGpuToCpu(count));
296     } else {
297       PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,d_buf,PETSC_MEMTYPE_HOST,h_buf,count));
298       PetscCall(PetscLogCpuToGpu(count));
299     }
300   }
301   PetscFunctionReturn(0);
302 }
303 
304 static inline PetscErrorCode PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(PetscSF sf,PetscSFLink link,PetscBool device2host)
305 {
306   PetscFunctionBegin;
307   if (PetscMemTypeDevice(link->leafmtype) && PetscMemTypeHost(link->leafmtype_mpi) && sf->leafbuflen[PETSCSF_REMOTE]) {
308     void  *h_buf = link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_HOST];
309     void  *d_buf = link->leafbuf[PETSCSF_REMOTE][PETSC_MEMTYPE_DEVICE];
310     size_t count = sf->leafbuflen[PETSCSF_REMOTE]*link->unitbytes;
311     if (device2host) {
312       PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_HOST,h_buf,PETSC_MEMTYPE_DEVICE,d_buf,count));
313       PetscCall(PetscLogGpuToCpu(count));
314     } else {
315       PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,d_buf,PETSC_MEMTYPE_HOST,h_buf,count));
316       PetscCall(PetscLogCpuToGpu(count));
317     }
318   }
319   PetscFunctionReturn(0);
320 }
321 
322 /* Make sure root/leafbuf for the remote is ready for MPI */
323 static inline PetscErrorCode PetscSFLinkSyncStreamBeforeCallMPI(PetscSF sf,PetscSFLink link,PetscSFDirection direction)
324 {
325   PetscSF_Basic  *bas;
326   PetscInt       buflen;
327   PetscMemType   mtype;
328 
329   PetscFunctionBegin;
330   if (direction == PETSCSF_ROOT2LEAF) {
331     bas    = (PetscSF_Basic*)sf->data;
332     mtype  = link->rootmtype;
333     buflen = bas->rootbuflen[PETSCSF_REMOTE];
334   } else {
335     mtype  = link->leafmtype;
336     buflen = sf->leafbuflen[PETSCSF_REMOTE];
337   }
338 
339   if (PetscMemTypeDevice(mtype) && buflen) {
340     PetscCall((*link->SyncStream)(link));
341   }
342   PetscFunctionReturn(0);
343 }
344 #else /* Host only */
345   #define PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(a,b,c)                  0
346   #define PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(a,b,c)                  0
347   #define PetscSFLinkSyncStreamBeforeCallMPI(a,b,c)                                0
348 #endif
349 
350 /* Get root indices used for pack/unpack
351 
352 Input arguments:
353   +sf    - StarForest
354   .link  - The link, which provides the stream for the async memcpy (In SF, we make all GPU operations asynchronous to avoid unexpected pipeline stalls)
355   .mtype - In what type of memory? (PETSC_MEMTYPE_DEVICE or PETSC_MEMTYPE_HOST)
356   -scope - Which part of the indices? (PETSCSF_LOCAL or PETSCSF_REMOTE)
357 
358  Output arguments:
359   +count   - Count of indices
360   .start   - The first index (only useful when indices is NULL)
361   .opt     - Packing optimizations
362   -indices - Indices of roots for pack/unpack. NULL means indices are contiguous
363  */
364 static inline PetscErrorCode PetscSFLinkGetRootPackOptAndIndices(PetscSF sf,PetscSFLink link,PetscMemType mtype,PetscSFScope scope,PetscInt *count,PetscInt *start,PetscSFPackOpt *opt,const PetscInt **indices)
365 {
366   PetscSF_Basic  *bas = (PetscSF_Basic*)sf->data;
367   PetscInt       offset;
368 
369   PetscFunctionBegin;
370   *count   = bas->rootbuflen[scope];
371   *start   = bas->rootstart[scope];
372   *opt     = NULL;
373   *indices = NULL;
374 
375   /* We have these rules:
376     1) opt == NULL && indices == NULL ==> indices are contiguous.
377     2) opt != NULL ==> indices are in 3D but not contiguous. On host, indices != NULL since indices are already available and we do not
378        want to enforce all operations to use opt; but on device, indices = NULL since we do not want to copy indices to device.
379   */
380   if (!bas->rootcontig[scope]) {
381     offset = (scope == PETSCSF_LOCAL)? 0 : bas->ioffset[bas->ndiranks];
382     if (PetscMemTypeHost(mtype)) {*opt = bas->rootpackopt[scope]; *indices = bas->irootloc + offset;}
383     else {
384       size_t         size;
385       if (bas->rootpackopt[scope]) {
386         if (!bas->rootpackopt_d[scope]) {
387           PetscCall(PetscMalloc1(1,&bas->rootpackopt_d[scope]));
388           PetscCall(PetscArraycpy(bas->rootpackopt_d[scope],bas->rootpackopt[scope],1)); /* Make pointers in bas->rootpackopt_d[] still work on host */
389           size = (bas->rootpackopt[scope]->n*7+2)*sizeof(PetscInt); /* See comments at struct _n_PetscSFPackOpt*/
390           PetscCall(PetscSFMalloc(sf,PETSC_MEMTYPE_DEVICE,size,(void **)&bas->rootpackopt_d[scope]->array));
391           PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,bas->rootpackopt_d[scope]->array,PETSC_MEMTYPE_HOST,bas->rootpackopt[scope]->array,size));
392         }
393         *opt = bas->rootpackopt_d[scope];
394       } else { /* On device, we only provide indices when there is no optimization. We're reluctant to copy indices to device. */
395         if (!bas->irootloc_d[scope]) {
396           size = bas->rootbuflen[scope]*sizeof(PetscInt);
397           PetscCall(PetscSFMalloc(sf,PETSC_MEMTYPE_DEVICE,size,(void **)&bas->irootloc_d[scope]));
398           PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,bas->irootloc_d[scope],PETSC_MEMTYPE_HOST,bas->irootloc+offset,size));
399         }
400         *indices = bas->irootloc_d[scope];
401       }
402     }
403   }
404   PetscFunctionReturn(0);
405 }
406 
407 /* Get leaf indices used for pack/unpack
408 
409   See also PetscSFLinkGetRootPackOptAndIndices()
410  */
411 static inline PetscErrorCode PetscSFLinkGetLeafPackOptAndIndices(PetscSF sf,PetscSFLink link,PetscMemType mtype,PetscSFScope scope,PetscInt *count,PetscInt *start,PetscSFPackOpt *opt,const PetscInt **indices)
412 {
413   PetscInt   offset;
414 
415   PetscFunctionBegin;
416   *count   = sf->leafbuflen[scope];
417   *start   = sf->leafstart[scope];
418   *opt     = NULL;
419   *indices = NULL;
420   if (!sf->leafcontig[scope]) {
421     offset = (scope == PETSCSF_LOCAL)? 0 : sf->roffset[sf->ndranks];
422     if (PetscMemTypeHost(mtype)) {*opt = sf->leafpackopt[scope]; *indices = sf->rmine + offset;}
423     else {
424       size_t         size;
425       if (sf->leafpackopt[scope]) {
426         if (!sf->leafpackopt_d[scope]) {
427           PetscCall(PetscMalloc1(1,&sf->leafpackopt_d[scope]));
428           PetscCall(PetscArraycpy(sf->leafpackopt_d[scope],sf->leafpackopt[scope],1));
429           size = (sf->leafpackopt[scope]->n*7+2)*sizeof(PetscInt); /* See comments at struct _n_PetscSFPackOpt*/
430           PetscCall(PetscSFMalloc(sf,PETSC_MEMTYPE_DEVICE,size,(void **)&sf->leafpackopt_d[scope]->array)); /* Change ->array to a device pointer */
431           PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,sf->leafpackopt_d[scope]->array,PETSC_MEMTYPE_HOST,sf->leafpackopt[scope]->array,size));
432         }
433         *opt = sf->leafpackopt_d[scope];
434       } else {
435         if (!sf->rmine_d[scope]) {
436           size = sf->leafbuflen[scope]*sizeof(PetscInt);
437           PetscCall(PetscSFMalloc(sf,PETSC_MEMTYPE_DEVICE,size,(void **)&sf->rmine_d[scope]));
438           PetscCall((*link->Memcpy)(link,PETSC_MEMTYPE_DEVICE,sf->rmine_d[scope],PETSC_MEMTYPE_HOST,sf->rmine+offset,size));
439         }
440         *indices = sf->rmine_d[scope];
441       }
442     }
443   }
444   PetscFunctionReturn(0);
445 }
446 #endif
447