xref: /petsc/src/ts/utils/dmplexlandau/kokkos/landau.kokkos.cxx (revision 8ebe3e4e9e00d86ece2e9fcd0cc84910b0ad437c)
1 /*
2   Implements the Kokkos kernel
3 */
4 #include <petscconf.h>
5 #include <petscvec_kokkos.hpp>
6 #include <petsc/private/dmpleximpl.h>   /*I   "petscdmplex.h"   I*/
7 #include <petsclandau.h>
8 #include <petscts.h>
9 
10 #include <Kokkos_Core.hpp>
11 #include <cstdio>
12 typedef Kokkos::TeamPolicy<>::member_type team_member;
13 #include "../land_tensors.h"
14 #include <petscaijdevice.h>
15 
16 namespace landau_inner_red {  // namespace helps with name resolution in reduction identity
17   template< class ScalarType >
18   struct array_type {
19     ScalarType gg2[LANDAU_DIM];
20     ScalarType gg3[LANDAU_DIM][LANDAU_DIM];
21 
22     KOKKOS_INLINE_FUNCTION   // Default constructor - Initialize to 0's
23     array_type() {
24       for (int j = 0; j < LANDAU_DIM; j++) {
25         gg2[j] = 0;
26         for (int k = 0; k < LANDAU_DIM; k++) {
27           gg3[j][k] = 0;
28         }
29       }
30     }
31     KOKKOS_INLINE_FUNCTION   // Copy Constructor
32     array_type(const array_type & rhs) {
33       for (int j = 0; j < LANDAU_DIM; j++) {
34         gg2[j] = rhs.gg2[j];
35         for (int k = 0; k < LANDAU_DIM; k++) {
36           gg3[j][k] = rhs.gg3[j][k];
37         }
38       }
39     }
40     KOKKOS_INLINE_FUNCTION   // add operator
41     array_type& operator += (const array_type& src)
42     {
43       for (int j = 0; j < LANDAU_DIM; j++) {
44         gg2[j] += src.gg2[j];
45         for (int k = 0; k < LANDAU_DIM; k++) {
46           gg3[j][k] += src.gg3[j][k];
47         }
48       }
49       return *this;
50     }
51     KOKKOS_INLINE_FUNCTION   // volatile add operator
52     void operator += (const volatile array_type& src) volatile
53     {
54       for (int j = 0; j < LANDAU_DIM; j++) {
55         gg2[j] += src.gg2[j];
56         for (int k = 0; k < LANDAU_DIM; k++) {
57           gg3[j][k] += src.gg3[j][k];
58         }
59       }
60     }
61   };
62   typedef array_type<PetscReal> TensorValueType;  // used to simplify code below
63 }
64 
65 namespace Kokkos { //reduction identity must be defined in Kokkos namespace
66   template<>
67   struct reduction_identity< landau_inner_red::TensorValueType > {
68     KOKKOS_FORCEINLINE_FUNCTION static landau_inner_red::TensorValueType sum() {
69       return landau_inner_red::TensorValueType();
70     }
71   };
72 }
73 
74 extern "C"  {
75 PetscErrorCode LandauKokkosCreateMatMaps(P4estVertexMaps maps[], pointInterpolationP4est (*pointMaps)[LANDAU_MAX_Q_FACE], PetscInt Nf[], PetscInt Nq, PetscInt grid)
76 {
77   P4estVertexMaps   h_maps;  /* host container */
78   const Kokkos::View<pointInterpolationP4est*[LANDAU_MAX_Q_FACE], Kokkos::LayoutRight, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> >    h_points ((pointInterpolationP4est*)pointMaps, maps[grid].num_reduced);
79   const Kokkos::View< LandauIdx*[LANDAU_MAX_SPECIES][LANDAU_MAX_NQ], Kokkos::LayoutRight, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_gidx ((LandauIdx*)maps[grid].gIdx, maps[grid].num_elements);
80   Kokkos::View<pointInterpolationP4est*[LANDAU_MAX_Q_FACE], Kokkos::LayoutRight>   *d_points = new Kokkos::View<pointInterpolationP4est*[LANDAU_MAX_Q_FACE], Kokkos::LayoutRight>("points", maps[grid].num_reduced);
81   Kokkos::View<LandauIdx*[LANDAU_MAX_SPECIES][LANDAU_MAX_NQ], Kokkos::LayoutRight> *d_gidx = new Kokkos::View<LandauIdx*[LANDAU_MAX_SPECIES][LANDAU_MAX_NQ], Kokkos::LayoutRight>("gIdx", maps[grid].num_elements);
82 
83   PetscFunctionBegin;
84   Kokkos::deep_copy (*d_gidx, h_gidx);
85   Kokkos::deep_copy (*d_points, h_points);
86   h_maps.num_elements = maps[grid].num_elements;
87   h_maps.num_face = maps[grid].num_face;
88   h_maps.num_reduced = maps[grid].num_reduced;
89   h_maps.deviceType = maps[grid].deviceType;
90   h_maps.numgrids = maps[grid].numgrids;
91   h_maps.Nf = Nf[grid];
92   h_maps.Nq = Nq;
93   h_maps.c_maps = (pointInterpolationP4est (*)[LANDAU_MAX_Q_FACE]) d_points->data();
94   maps[grid].vp1 = (void*)d_points;
95   h_maps.gIdx = (LandauIdx (*)[LANDAU_MAX_SPECIES][LANDAU_MAX_NQ]) d_gidx->data();
96   maps[grid].vp2 = (void*)d_gidx;
97   {
98     Kokkos::View<P4estVertexMaps, Kokkos::HostSpace> h_maps_k(&h_maps);
99     Kokkos::View<P4estVertexMaps>                    *d_maps_k = new Kokkos::View<P4estVertexMaps>(Kokkos::create_mirror(Kokkos::DefaultExecutionSpace::memory_space(),h_maps_k));
100     Kokkos::deep_copy (*d_maps_k, h_maps_k);
101     maps[grid].d_self = d_maps_k->data();
102     maps[grid].vp3 = (void*)d_maps_k;
103   }
104   PetscFunctionReturn(0);
105 }
106 PetscErrorCode LandauKokkosDestroyMatMaps(P4estVertexMaps maps[], PetscInt num_grids)
107 {
108   PetscFunctionBegin;
109   for (PetscInt grid=0;grid<num_grids;grid++) {
110     auto a = static_cast<Kokkos::View<pointInterpolationP4est*[LANDAU_MAX_Q_FACE], Kokkos::LayoutRight>*>(maps[grid].vp1);
111     auto b = static_cast<Kokkos::View<LandauIdx*[LANDAU_MAX_SPECIES][LANDAU_MAX_NQ], Kokkos::LayoutRight>*>(maps[grid].vp2);
112     auto c = static_cast<Kokkos::View<P4estVertexMaps*>*>(maps[grid].vp3);
113     delete a;  delete b;  delete c;
114   }
115   PetscFunctionReturn(0);
116 }
117 
118 PetscErrorCode LandauKokkosStaticDataSet(DM plex, const PetscInt Nq, const PetscInt batch_sz, const PetscInt num_grids,
119                                          PetscInt a_numCells[], PetscInt a_species_offset[], PetscInt a_mat_offset[],
120                                          PetscReal a_nu_alpha[], PetscReal a_nu_beta[], PetscReal a_invMass[], PetscReal a_invJ[],
121                                          PetscReal a_x[], PetscReal a_y[], PetscReal a_z[], PetscReal a_w[], LandauStaticData *SData_d)
122 {
123   PetscReal       *BB,*DD;
124   PetscErrorCode  ierr;
125   PetscTabulation *Tf;
126   PetscInt        dim;
127   PetscInt        Nb=Nq,ip_offset[LANDAU_MAX_GRIDS+1],ipf_offset[LANDAU_MAX_GRIDS+1],elem_offset[LANDAU_MAX_GRIDS+1],nip,IPf_sz,Nftot;
128   PetscDS         prob;
129 
130   PetscFunctionBegin;
131   ierr = DMGetDimension(plex, &dim);CHKERRQ(ierr);
132   ierr = DMGetDS(plex, &prob);CHKERRQ(ierr);
133   if (LANDAU_DIM != dim) SETERRQ2(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "dim %D != LANDAU_DIM %d",dim,LANDAU_DIM);
134   ierr = PetscDSGetTabulation(prob, &Tf);CHKERRQ(ierr);
135   BB   = Tf[0]->T[0]; DD = Tf[0]->T[1];
136   ip_offset[0] = ipf_offset[0] = elem_offset[0] = 0;
137   nip = 0;
138   IPf_sz = 0;
139   for (PetscInt grid=0 ; grid<num_grids ; grid++) {
140     PetscInt nfloc = a_species_offset[grid+1] - a_species_offset[grid];
141     elem_offset[grid+1] = elem_offset[grid] + a_numCells[grid];
142     nip += a_numCells[grid]*Nq;
143     ip_offset[grid+1] = nip;
144     IPf_sz += Nq*nfloc*a_numCells[grid];
145     ipf_offset[grid+1] = IPf_sz;
146   }
147   Nftot = a_species_offset[num_grids];
148   ierr = PetscKokkosInitializeCheck();CHKERRQ(ierr);
149   {
150     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_alpha (a_nu_alpha, Nftot);
151     auto alpha = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("alpha", Nftot);
152     SData_d->alpha = static_cast<void*>(alpha);
153     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_beta (a_nu_beta, Nftot);
154     auto beta = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("beta", Nftot);
155     SData_d->beta = static_cast<void*>(beta);
156     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_invMass (a_invMass,Nftot);
157     auto invMass = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("invMass", Nftot);
158     SData_d->invMass = static_cast<void*>(invMass);
159     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_BB (BB,Nq*Nb);
160     auto B = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("B", Nq*Nb);
161     SData_d->B = static_cast<void*>(B);
162     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_DD (DD,Nq*Nb*dim);
163     auto D = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("D", Nq*Nb*dim);
164     SData_d->D = static_cast<void*>(D);
165     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_invJ (a_invJ, nip*dim*dim);
166     auto invJ = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("invJ", nip*dim*dim);
167     SData_d->invJ = static_cast<void*>(invJ);
168     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_x (a_x, nip);
169     auto x = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("x", nip);
170     SData_d->x = static_cast<void*>(x);
171     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_y (a_y, nip);
172     auto y = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("y", nip);
173     SData_d->y = static_cast<void*>(y);
174     const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_w (a_w, nip);
175     auto w = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("w", nip);
176     SData_d->w = static_cast<void*>(w);
177 
178     Kokkos::deep_copy (*alpha, h_alpha);
179     Kokkos::deep_copy (*beta, h_beta);
180     Kokkos::deep_copy (*invMass, h_invMass);
181     Kokkos::deep_copy (*B, h_BB);
182     Kokkos::deep_copy (*D, h_DD);
183     Kokkos::deep_copy (*invJ, h_invJ);
184     Kokkos::deep_copy (*x, h_x);
185     Kokkos::deep_copy (*y, h_y);
186     Kokkos::deep_copy (*w, h_w);
187 
188     if (dim==3) {
189       const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_z (a_z , dim==3 ? nip : 0);
190       auto z = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("z", nip);
191       SData_d->z = static_cast<void*>(z);
192       Kokkos::deep_copy (*z, h_z);
193     } else SData_d->z = NULL;
194 
195     //
196     const Kokkos::View<PetscInt*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_NCells (a_numCells, num_grids);
197     auto nc = new Kokkos::View<PetscInt*, Kokkos::LayoutLeft> ("NCells",num_grids);
198     SData_d->NCells = static_cast<void*>(nc);
199     Kokkos::deep_copy (*nc, h_NCells);
200 
201     const Kokkos::View<PetscInt*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_species_offset (a_species_offset, num_grids+1);
202     auto soff = new Kokkos::View<PetscInt*, Kokkos::LayoutLeft> ("species_offset",num_grids+1);
203     SData_d->species_offset = static_cast<void*>(soff);
204     Kokkos::deep_copy (*soff, h_species_offset);
205 
206     const Kokkos::View<PetscInt*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_mat_offset (a_mat_offset, num_grids+1);
207     auto moff = new Kokkos::View<PetscInt*, Kokkos::LayoutLeft> ("mat_offset",num_grids+1);
208     SData_d->mat_offset = static_cast<void*>(moff);
209     Kokkos::deep_copy (*moff, h_mat_offset);
210 
211     const Kokkos::View<PetscInt*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_ip_offset (ip_offset, num_grids+1);
212     auto ipoff = new Kokkos::View<PetscInt*, Kokkos::LayoutLeft> ("ip_offset",num_grids+1);
213     SData_d->ip_offset = static_cast<void*>(ipoff);
214     Kokkos::deep_copy (*ipoff,  h_ip_offset);
215 
216     const Kokkos::View<PetscInt*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_elem_offset (elem_offset, num_grids+1);
217     auto eoff = new Kokkos::View<PetscInt*, Kokkos::LayoutLeft> ("elem_offset",num_grids+1);
218     SData_d->elem_offset = static_cast<void*>(eoff);
219     Kokkos::deep_copy (*eoff,  h_elem_offset);
220 
221     const Kokkos::View<PetscInt*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_ipf_offset (ipf_offset, num_grids+1);
222     auto ipfoff = new Kokkos::View<PetscInt*, Kokkos::LayoutLeft> ("ipf_offset",num_grids+1);
223     SData_d->ipf_offset = static_cast<void*>(ipfoff);
224     Kokkos::deep_copy (*ipfoff,  h_ipf_offset);
225 #if defined(LANDAU_LAYOUT_LEFT) // preallocate dynamic data, no copy
226     auto ipfdf_data =  new Kokkos::View<PetscReal***, Kokkos::LayoutLeft > ("fdf", batch_sz, dim+1, IPf_sz);
227 #else
228     auto ipfdf_data =  new Kokkos::View<PetscReal***, Kokkos::LayoutRight > ("fdf",batch_sz,  dim+1, IPf_sz);
229 #endif
230     SData_d->ipfdf_data = static_cast<void*>(ipfdf_data);
231     auto Eq_m = new Kokkos::View<PetscReal*, Kokkos::LayoutLeft> ("Eq_m",Nftot); // allocate but do not set, same for whole batch
232     SData_d->Eq_m = static_cast<void*>(Eq_m);
233   }
234   SData_d->maps = NULL; // not used
235   PetscFunctionReturn(0);
236 }
237 
238 PetscErrorCode LandauKokkosStaticDataClear(LandauStaticData *SData_d)
239 {
240   PetscFunctionBegin;
241   if (SData_d->alpha) {
242     auto alpha = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->alpha);
243     delete alpha;
244     SData_d->alpha = NULL;
245     auto beta = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->beta);
246     delete beta;
247     auto invMass = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->invMass);
248     delete invMass;
249     auto B = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->B);
250     delete B;
251     auto D = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->D);
252     delete D;
253     auto invJ = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->invJ);
254     delete invJ;
255     auto x = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->x);
256     delete x;
257     auto y = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->y);
258     delete y;
259     if (SData_d->z) {
260       auto z = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->z);
261       delete z;
262     }
263 #if defined(LANDAU_LAYOUT_LEFT) // preallocate dynamic data, no copy
264     auto z = static_cast<Kokkos::View<PetscReal***, Kokkos::LayoutLeft>*>(SData_d->ipfdf_data);
265 #else
266     auto z = static_cast<Kokkos::View<PetscReal***, Kokkos::LayoutRight>*>(SData_d->ipfdf_data);
267 #endif
268     delete z;
269     auto w = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->w);
270     delete w;
271     auto Eq_m = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->Eq_m);
272     delete Eq_m;
273     // offset
274     auto nc = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->NCells);
275     delete nc;
276     auto soff = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->species_offset);
277     delete soff;
278     auto moff = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->mat_offset);
279     delete moff;
280     auto ipoff = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->ip_offset);
281     delete ipoff;
282     auto eoff = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->elem_offset);
283     delete eoff;
284     auto ipfoff = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->ipf_offset);
285     delete ipfoff;
286   }
287   PetscFunctionReturn(0);
288 }
289 
290 #define KOKKOS_SHARED_LEVEL 1
291 KOKKOS_INLINE_FUNCTION
292 PetscErrorCode landau_mat_assemble(PetscSplitCSRDataStructure d_mat, const team_member team,
293                                    Kokkos::View<PetscScalar**, Kokkos::LayoutRight, Kokkos::DefaultExecutionSpace::scratch_memory_space> s_fieldMats,
294                                    Kokkos::View<PetscInt**, Kokkos::LayoutRight, Kokkos::DefaultExecutionSpace::scratch_memory_space>  s_idx,
295                                    Kokkos::View<PetscReal**, Kokkos::LayoutRight, Kokkos::DefaultExecutionSpace::scratch_memory_space> s_scale,
296                                    const PetscInt Nb, const PetscInt Nq, const PetscInt nfaces, const PetscInt moffset, const PetscInt elem, const PetscInt fieldA, const P4estVertexMaps *d_maps)
297 {
298   const LandauIdx *const Idxs = &d_maps->gIdx[elem][fieldA][0];
299   team.team_barrier();
300   Kokkos::parallel_for(Kokkos::TeamVectorRange(team,0,Nb), [=] (int f) {
301       PetscInt q, idx = Idxs[f];
302       if (idx >= 0) {
303         s_idx(f,0) = idx + moffset;
304         s_scale(f,0) = 1.;
305       } else {
306         idx = -idx - 1;
307         for (q = 0; q < nfaces; q++) {
308           s_idx(f,q) = d_maps->c_maps[idx][q].gid + moffset;
309           s_scale(f,q) = d_maps->c_maps[idx][q].scale;
310         }
311       }
312     });
313   team.team_barrier();
314   Kokkos::parallel_for(Kokkos::TeamThreadRange(team,0,Nb), [=] (int f) {
315       PetscInt nr,idx = Idxs[f];
316       if (idx >= 0) {
317         nr = 1;
318       } else {
319         nr = nfaces;
320       }
321       Kokkos::parallel_for(Kokkos::ThreadVectorRange(team,0,Nb), [=] (int g) {
322           PetscScalar     vals[LANDAU_MAX_Q_FACE*LANDAU_MAX_Q_FACE];
323           PetscInt        q,d,nc,idx = Idxs[g];
324           if (idx >= 0) {
325             nc = 1;
326           } else {
327             nc = nfaces;
328           }
329           for (q = 0; q < nr; q++) {
330             for (d = 0; d < nc; d++) {
331               vals[q*nc + d] = s_scale(f,q)*s_scale(g,d)*s_fieldMats(f,g);
332             }
333           }
334           MatSetValuesDevice(d_mat,nr,&s_idx(f,0),nc,&s_idx(g,0),vals,ADD_VALUES);
335         });
336     });
337   return 0;
338 }
339 
340 PetscErrorCode LandauKokkosJacobian(DM plex[], const PetscInt Nq, const PetscInt batch_sz, const PetscInt num_grids, const PetscInt a_numCells[], PetscReal a_Eq_m[], PetscScalar a_elem_closure[],
341                                     const PetscScalar a_xarray[], const LandauStaticData *SData_d, const PetscInt num_sub_blocks, const PetscReal shift,
342                                     const PetscLogEvent events[], const PetscInt a_mat_offset[], const PetscInt a_species_offset[], Mat subJ[], Mat JacP)
343 {
344   using scr_mem_t = Kokkos::DefaultExecutionSpace::scratch_memory_space;
345   using fieldMats_scr_t = Kokkos::View<PetscScalar**, Kokkos::LayoutRight, scr_mem_t>;
346   using real2_scr_t = Kokkos::View<PetscScalar**, Kokkos::LayoutRight, scr_mem_t>;
347   using idx_scr_t = Kokkos::View<PetscInt**, Kokkos::LayoutRight, scr_mem_t>;
348   using scale_scr_t = Kokkos::View<PetscReal**, Kokkos::LayoutRight, scr_mem_t>;
349   using g2_scr_t = Kokkos::View<PetscReal***, Kokkos::LayoutRight, scr_mem_t>;
350   using g3_scr_t = Kokkos::View<PetscReal****, Kokkos::LayoutRight, scr_mem_t>;
351   PetscErrorCode    ierr;
352   PetscInt          Nb=Nq,dim,num_cells_max,Nf_max,num_cells_batch;
353   int               nfaces=0;
354   LandauCtx         *ctx;
355   PetscReal         *d_Eq_m=NULL;
356   PetscScalar       *d_vertex_f=NULL;
357   P4estVertexMaps   *maps[LANDAU_MAX_GRIDS]; // this gets captured
358   PetscSplitCSRDataStructure d_mat;
359   PetscContainer    container;
360   const int         conc = Kokkos::DefaultExecutionSpace().concurrency(), openmp = !!(conc < 1000), team_size = (openmp==0) ? Nq : 1;
361   auto              d_alpha_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->alpha); //static data
362   const PetscReal   *d_alpha = d_alpha_k->data();
363   const PetscInt    Nftot = d_alpha_k->size(); // total number of species
364   auto              d_beta_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->beta);
365   const PetscReal   *d_beta = d_beta_k->data();
366   auto              d_invMass_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->invMass);
367   const PetscReal   *d_invMass = d_invMass_k->data();
368   auto              d_B_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->B);
369   const PetscReal   *d_BB = d_B_k->data();
370   auto              d_D_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->D);
371   const PetscReal   *d_DD = d_D_k->data();
372   auto              d_invJ_k = *static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->invJ);     // use Kokkos vector in kernels
373   auto              d_x_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->x); //static data
374   const PetscReal   *d_x = d_x_k->data();
375   auto              d_y_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->y); //static data
376   const PetscReal   *d_y = d_y_k->data();
377   auto              d_z_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->z); //static data
378   const PetscReal   *d_z = (LANDAU_DIM==3) ? d_z_k->data() : NULL;
379   auto              d_w_k = *static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->w); //static data
380   const PetscReal   *d_w = d_w_k.data();
381   // grid offsets - single vertex grid data
382   auto              d_numCells_k = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->NCells);
383   const PetscInt   *d_numCells = d_numCells_k->data();
384   auto              d_species_offset_k = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->species_offset);
385   const PetscInt   *d_species_offset = d_species_offset_k->data();
386   auto              d_mat_offset_k = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->mat_offset);
387   const PetscInt   *d_mat_offset = d_mat_offset_k->data();
388   auto              d_ip_offset_k = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->ip_offset);
389   const PetscInt   *d_ip_offset = d_ip_offset_k->data();
390   auto              d_ipf_offset_k = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->ipf_offset);
391   const PetscInt   *d_ipf_offset = d_ipf_offset_k->data();
392   auto              d_elem_offset_k = static_cast<Kokkos::View<PetscInt*, Kokkos::LayoutLeft>*>(SData_d->elem_offset);
393   const PetscInt   *d_elem_offset = d_elem_offset_k->data();
394 #if defined(LANDAU_LAYOUT_LEFT)         // preallocate dynamic data, including batched vertices
395   Kokkos::View<PetscReal***, Kokkos::LayoutLeft > d_fdf_k = *static_cast<Kokkos::View<PetscReal***, Kokkos::LayoutLeft >*>(SData_d->ipfdf_data);
396 #else
397   Kokkos::View<PetscReal***, Kokkos::LayoutRight > d_fdf_k = *static_cast<Kokkos::View<PetscReal***, Kokkos::LayoutRight >*>(SData_d->ipfdf_data);
398 #endif
399   auto              d_Eq_m_k = static_cast<Kokkos::View<PetscReal*, Kokkos::LayoutLeft>*>(SData_d->Eq_m); // static storage, dynamci data - E(t), copy later, single vertex
400 
401   PetscFunctionBegin;
402   ierr = PetscLogEventBegin(events[3],0,0,0,0);CHKERRQ(ierr);
403   ierr = DMGetApplicationContext(plex[0], &ctx);CHKERRQ(ierr);
404   if (!ctx) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "no context");
405   ierr = DMGetDimension(plex[0], &dim);CHKERRQ(ierr);
406   if (LANDAU_DIM != dim) SETERRQ2(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "dim %D != LANDAU_DIM %d",dim,LANDAU_DIM);
407   if (ctx->gpu_assembly) {
408     ierr = PetscObjectQuery((PetscObject) JacP, "assembly_maps", (PetscObject *) &container);CHKERRQ(ierr);
409     if (container) { // not here first call
410       P4estVertexMaps   *h_maps=NULL;
411       ierr = PetscContainerGetPointer(container, (void **) &h_maps);CHKERRQ(ierr);
412       for (PetscInt grid=0 ; grid<num_grids ; grid++) {
413         if (h_maps[grid].d_self) {
414           maps[grid] = h_maps[grid].d_self;
415           nfaces = h_maps[grid].num_face; // nface=0 for CPU assembly
416         } else {
417           SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "GPU assembly but no metadata in container");
418         }
419       }
420       // this does the setup the first time called
421       ierr = MatKokkosGetDeviceMatWrite(JacP,&d_mat);CHKERRQ(ierr);
422     } else { // kernel output - first call assembled on device
423       for (PetscInt grid=0 ; grid<num_grids ; grid++) maps[grid] = NULL;
424       nfaces = 0;
425       d_mat = NULL;
426     }
427   } else {
428     for (PetscInt grid=0 ; grid<num_grids ; grid++) maps[grid] = NULL;
429     nfaces = 0;
430     d_mat = NULL;
431     container = NULL;
432   }
433   num_cells_batch = Nf_max = num_cells_max = 0;
434   for (PetscInt grid=0 ; grid<num_grids ; grid++) {
435     int Nfloc = a_species_offset[grid+1] - a_species_offset[grid];
436     if (Nfloc > Nf_max) Nf_max = Nfloc;
437     if (a_numCells[grid] > num_cells_max) num_cells_max = a_numCells[grid];
438     num_cells_batch += a_numCells[grid]; // we don't have a host element offset here (but in ctx)
439   }
440   const PetscInt totDim_max = Nf_max*Nq, elem_mat_size_max = totDim_max*totDim_max;
441   const PetscInt elem_mat_num_cells_max_grid = container ? 0 : num_cells_max;
442   Kokkos::View<PetscScalar****, Kokkos::LayoutRight> d_elem_mats("element matrices", batch_sz, num_grids, elem_mat_num_cells_max_grid, elem_mat_size_max); // first call have large set of global (Jac) element matrices
443   const Kokkos::View<PetscReal*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> >  h_Eq_m_k (a_Eq_m, Nftot);
444   if (a_elem_closure || a_xarray) {
445     Kokkos::deep_copy (*d_Eq_m_k, h_Eq_m_k);
446     d_Eq_m = d_Eq_m_k->data();
447   } else d_Eq_m = NULL;
448   ierr = PetscKokkosInitializeCheck();CHKERRQ(ierr);
449   ierr = PetscLogEventEnd(events[3],0,0,0,0);CHKERRQ(ierr);
450   if (a_elem_closure || a_xarray) { // Jacobian, create f & df
451     Kokkos::View<PetscScalar*, Kokkos::LayoutLeft> *d_vertex_f_k = NULL;
452     ierr = PetscLogEventBegin(events[1],0,0,0,0);CHKERRQ(ierr);
453     if (a_elem_closure) {
454       PetscInt closure_sz = 0; // argh, don't have this on the host!!!
455       for (PetscInt grid=0 ; grid<num_grids ; grid++) {
456         PetscInt nfloc = a_species_offset[grid+1] - a_species_offset[grid];
457         closure_sz     += Nq*nfloc*a_numCells[grid];
458       }
459       closure_sz *= batch_sz;
460       d_vertex_f_k = new Kokkos::View<PetscScalar*, Kokkos::LayoutLeft> ("closure",closure_sz);
461       const Kokkos::View<PetscScalar*, Kokkos::LayoutLeft, Kokkos::HostSpace, Kokkos::MemoryTraits<Kokkos::Unmanaged> > h_closure_k (a_elem_closure, closure_sz); // Vertex data for each element
462       Kokkos::deep_copy (*d_vertex_f_k, h_closure_k);
463       d_vertex_f  = d_vertex_f_k->data();
464     } else {
465       d_vertex_f = (PetscScalar*)a_xarray;
466     }
467     ierr = PetscLogEventEnd(events[1],0,0,0,0);CHKERRQ(ierr);
468     ierr = PetscLogEventBegin(events[8],0,0,0,0);CHKERRQ(ierr);
469     ierr = PetscLogGpuTimeBegin();CHKERRQ(ierr);
470 
471     const int scr_bytes_fdf = real2_scr_t::shmem_size(Nf_max,Nb);
472     ierr = PetscInfo6(plex[0], "Jacobian shared memory size: %d bytes in level %d num cells total=%D team size=%D #face=%D Nf_max=%D\n",scr_bytes_fdf,KOKKOS_SHARED_LEVEL,num_cells_batch*batch_sz,team_size,nfaces,Nf_max);CHKERRQ(ierr);
473     Kokkos::parallel_for("f, df", Kokkos::TeamPolicy<>(num_cells_batch*batch_sz, team_size, /* Kokkos::AUTO */ 16).set_scratch_size(KOKKOS_SHARED_LEVEL, Kokkos::PerTeam(scr_bytes_fdf)), KOKKOS_LAMBDA (const team_member team) {
474         const PetscInt b_Nelem = d_elem_offset[num_grids], b_elem_idx = team.league_rank()%b_Nelem, b_id = team.league_rank()/b_Nelem, IPf_sz_glb = d_ipf_offset[num_grids];
475         // find my grid
476         PetscInt grid = 0;
477         while (b_elem_idx >= d_elem_offset[grid+1]) grid++;
478         {
479           const PetscInt     loc_nip = d_numCells[grid]*Nq, loc_Nf = d_species_offset[grid+1] - d_species_offset[grid], loc_elem = b_elem_idx - d_elem_offset[grid];
480           const PetscInt     moffset = LAND_MOFFSET(b_id,grid,batch_sz,num_grids,d_mat_offset);
481           {
482             real2_scr_t    s_coef_k(team.team_scratch(KOKKOS_SHARED_LEVEL),Nf_max,Nb);
483             PetscScalar     *coef;
484             const PetscReal *invJe = &d_invJ_k((d_ip_offset[grid] + loc_elem*Nq)*dim*dim);
485             // un pack IPData
486             if (!maps[grid]) {
487               coef = &d_vertex_f[b_id*IPf_sz_glb + d_ipf_offset[grid] + loc_elem*Nb*loc_Nf]; // closure and IP indexing are the same
488             } else {
489               coef = s_coef_k.data();
490               Kokkos::parallel_for(Kokkos::TeamThreadRange(team,0,(int)loc_Nf), [=] (int f) {
491                   //for (int f = 0; f < loc_Nf; ++f) {
492                   Kokkos::parallel_for(Kokkos::ThreadVectorRange(team,0,(int)Nb), [=] (int b) {
493                       //for (int b = 0; b < Nb; ++b) {
494                       LandauIdx idx = maps[grid]->gIdx[loc_elem][f][b];
495                       if (idx >= 0) {
496                         coef[f*Nb+b] = d_vertex_f[idx+moffset]; // xarray data, not IP, need raw array to deal with CPU assemble case (not used)
497                       } else {
498                         idx = -idx - 1;
499                         coef[f*Nb+b] = 0;
500                         for (int q = 0; q < maps[grid]->num_face; q++) {
501                           PetscInt    id = maps[grid]->c_maps[idx][q].gid;
502                           PetscScalar scale = maps[grid]->c_maps[idx][q].scale;
503                           coef[f*Nb+b] += scale*d_vertex_f[id+moffset];
504                         }
505                       }
506                     });
507                 });
508             }
509             team.team_barrier();
510             Kokkos::parallel_for(Kokkos::TeamThreadRange(team,0,Nq), [=] (int myQi) {
511                 const PetscReal *const  invJ = &invJe[myQi*dim*dim]; // b_elem_idx: batch element index
512                 const PetscReal         *Bq = &d_BB[myQi*Nb], *Dq = &d_DD[myQi*Nb*dim];
513                 Kokkos::parallel_for(Kokkos::ThreadVectorRange(team,0,(int)loc_Nf), [=] (int f) {
514                     PetscInt   b, e, d;
515                     PetscReal  refSpaceDer[LANDAU_DIM];
516                     const PetscInt idx = d_ipf_offset[grid] + f*loc_nip + loc_elem*Nq + myQi;
517                     d_fdf_k(b_id,0,idx) = 0.0;
518                     for (d = 0; d < LANDAU_DIM; ++d) refSpaceDer[d] = 0.0;
519                     for (b = 0; b < Nb; ++b) {
520                       d_fdf_k(b_id,0,idx) += Bq[b]*PetscRealPart(coef[f*Nb+b]);
521                       for (d = 0; d < dim; ++d) refSpaceDer[d] += Dq[b*dim+d]*PetscRealPart(coef[f*Nb+b]);
522                     }
523                     for (d = 0; d < dim; ++d) {
524                       for (e = 0, d_fdf_k(b_id,d+1,idx) = 0.0; e < dim; ++e) {
525                         d_fdf_k(b_id,d+1,idx) += invJ[e*dim+d]*refSpaceDer[e];
526                       }
527                     }
528                   }); // f
529               }); // myQi
530           }
531           team.team_barrier();
532         } // 'grid' scope
533       }); // global elems - fdf
534     Kokkos::fence();
535     ierr = PetscLogGpuTimeEnd();CHKERRQ(ierr); // is this a fence?
536     ierr = PetscLogEventEnd(events[8],0,0,0,0);CHKERRQ(ierr);
537     // Jacobian
538     ierr = PetscLogEventBegin(events[4],0,0,0,0);CHKERRQ(ierr);
539     ierr = PetscLogGpuTimeBegin();CHKERRQ(ierr);
540     const int scr_bytes = 2*(g2_scr_t::shmem_size(dim,Nf_max,Nq) + g3_scr_t::shmem_size(dim,dim,Nf_max,Nq))+fieldMats_scr_t::shmem_size(Nb,Nb)+idx_scr_t::shmem_size(Nb,nfaces)+scale_scr_t::shmem_size(Nb,nfaces);
541     Kokkos::parallel_for("Jacobian", Kokkos::TeamPolicy<>(num_cells_batch*batch_sz, team_size, /* Kokkos::AUTO */ 16).set_scratch_size(KOKKOS_SHARED_LEVEL, Kokkos::PerTeam(scr_bytes)), KOKKOS_LAMBDA (const team_member team) {
542         const PetscInt b_Nelem = d_elem_offset[num_grids], b_elem_idx = team.league_rank()%b_Nelem, b_id = team.league_rank()/b_Nelem;
543         // find my grid
544         PetscInt grid = 0;
545         while (b_elem_idx >= d_elem_offset[grid+1]) grid++;
546         {
547           const PetscInt  loc_Nf = d_species_offset[grid+1]-d_species_offset[grid], loc_elem = b_elem_idx - d_elem_offset[grid];
548           const PetscInt  moffset = LAND_MOFFSET(b_id,grid,batch_sz,num_grids,d_mat_offset);
549           const PetscInt  f_off = d_species_offset[grid], totDim = loc_Nf*Nq;
550           g2_scr_t        g2(team.team_scratch(KOKKOS_SHARED_LEVEL),dim,loc_Nf,Nq);
551           g3_scr_t        g3(team.team_scratch(KOKKOS_SHARED_LEVEL),dim,dim,loc_Nf,Nq);
552           g2_scr_t        gg2(team.team_scratch(KOKKOS_SHARED_LEVEL),dim,loc_Nf,Nq);
553           g3_scr_t        gg3(team.team_scratch(KOKKOS_SHARED_LEVEL),dim,dim,loc_Nf,Nq);
554           // get g2[] & g3[]
555           Kokkos::parallel_for(Kokkos::TeamThreadRange(team,0,Nq), [=] (int myQi) {
556               using Kokkos::parallel_reduce;
557               const PetscInt  jpidx_glb = d_ip_offset[grid] + loc_elem * Nq + myQi;
558               const PetscReal *invJ = &d_invJ_k(jpidx_glb*dim*dim);
559               const PetscReal vj[3] = {d_x[jpidx_glb], d_y[jpidx_glb], d_z ? d_z[jpidx_glb] : 0}, wj = d_w[jpidx_glb];
560               landau_inner_red::TensorValueType gg_temp; // reduce on part of gg2 and g33 for IP jpidx_g
561               Kokkos::parallel_reduce(Kokkos::ThreadVectorRange (team, (int)d_ip_offset[num_grids]), [=] (const int& ipidx, landau_inner_red::TensorValueType & ggg) {
562                   const PetscReal wi = d_w[ipidx], x = d_x[ipidx], y = d_y[ipidx];
563                   PetscReal       temp1[3] = {0, 0, 0}, temp2 = 0;
564                   PetscInt        fieldA,d2,d3,f_off_r,grid_r,ipidx_g,nip_loc_r,loc_Nf_r;
565 #if LANDAU_DIM==2
566                   PetscReal Ud[2][2], Uk[2][2], mask = (PetscAbs(vj[0]-x) < 100*PETSC_SQRT_MACHINE_EPSILON && PetscAbs(vj[1]-y) < 100*PETSC_SQRT_MACHINE_EPSILON) ? 0. : 1.;
567                   LandauTensor2D(vj, x, y, Ud, Uk, mask);
568 #else
569                   PetscReal U[3][3], z = d_z[jpidx_glb], mask = (PetscAbs(vj[0]-x) < 100*PETSC_SQRT_MACHINE_EPSILON && PetscAbs(vj[1]-y) < 100*PETSC_SQRT_MACHINE_EPSILON && PetscAbs(vj[2]-z) < 100*PETSC_SQRT_MACHINE_EPSILON) ? 0. : 1.;
570                   LandauTensor3D(vj, x, y, z, U, mask);
571 #endif
572                   grid_r = 0;
573                   while (ipidx >= d_ip_offset[grid_r+1]) grid_r++; // yuck search for grid
574                   f_off_r = d_species_offset[grid_r];
575                   ipidx_g = ipidx - d_ip_offset[grid_r];
576                   nip_loc_r = d_numCells[grid_r]*Nq;
577                   loc_Nf_r = d_species_offset[grid_r+1] - d_species_offset[grid_r];
578                   for (fieldA = 0; fieldA < loc_Nf_r; ++fieldA) {
579                     const PetscInt idx = d_ipf_offset[grid_r] + fieldA*nip_loc_r + ipidx_g;
580                     temp1[0] += d_fdf_k(b_id,1,idx)*d_beta[fieldA+f_off_r]*d_invMass[fieldA+f_off_r];
581                     temp1[1] += d_fdf_k(b_id,2,idx)*d_beta[fieldA+f_off_r]*d_invMass[fieldA+f_off_r];
582 #if LANDAU_DIM==3
583                     temp1[2] += d_fdf_k(b_id,3,idx)*d_beta[fieldA+f_off_r]*d_invMass[fieldA+f_off_r];
584 #endif
585                     temp2    += d_fdf_k(b_id,0,idx)*d_beta[fieldA+f_off_r];
586                   }
587                   temp1[0] *= wi;
588                   temp1[1] *= wi;
589 #if LANDAU_DIM==3
590                   temp1[2] *= wi;
591 #endif
592                   temp2    *= wi;
593 #if LANDAU_DIM==2
594                   for (d2 = 0; d2 < 2; d2++) {
595                     for (d3 = 0; d3 < 2; ++d3) {
596                       /* K = U * grad(f): g2=e: i,A */
597                       ggg.gg2[d2] += Uk[d2][d3]*temp1[d3];
598                       /* D = -U * (I \kron (fx)): g3=f: i,j,A */
599                       ggg.gg3[d2][d3] += Ud[d2][d3]*temp2;
600                     }
601                   }
602 #else
603                   for (d2 = 0; d2 < 3; ++d2) {
604                     for (d3 = 0; d3 < 3; ++d3) {
605                       /* K = U * grad(f): g2 = e: i,A */
606                       ggg.gg2[d2] += U[d2][d3]*temp1[d3];
607                       /* D = -U * (I \kron (fx)): g3 = f: i,j,A */
608                       ggg.gg3[d2][d3] += U[d2][d3]*temp2;
609                     }
610                   }
611 #endif
612                 }, Kokkos::Sum<landau_inner_red::TensorValueType>(gg_temp));
613               // add alpha and put in gg2/3
614               Kokkos::parallel_for(Kokkos::ThreadVectorRange (team, (int)loc_Nf), [&] (const int& fieldA) {
615                   PetscInt d2,d3;
616                   for (d2 = 0; d2 < dim; d2++) {
617                     gg2(d2,fieldA,myQi) = gg_temp.gg2[d2]*d_alpha[fieldA+f_off];
618                     for (d3 = 0; d3 < dim; d3++) {
619                       gg3(d2,d3,fieldA,myQi) = -gg_temp.gg3[d2][d3]*d_alpha[fieldA+f_off]*d_invMass[fieldA+f_off];
620                     }
621                   }
622                 });
623               /* add electric field term once per IP */
624               Kokkos::parallel_for(Kokkos::ThreadVectorRange (team, (int)loc_Nf), [&] (const int& fieldA) {
625                   gg2(dim-1,fieldA,myQi) += d_Eq_m[fieldA+f_off];
626                 });
627               Kokkos::parallel_for(Kokkos::ThreadVectorRange (team, (int)loc_Nf), [=] (const int& fieldA) {
628                   int d,d2,d3,dp;
629                   /* Jacobian transform - g2, g3 - per thread (2D) */
630                   for (d = 0; d < dim; ++d) {
631                     g2(d,fieldA,myQi) = 0;
632                     for (d2 = 0; d2 < dim; ++d2) {
633                       g2(d,fieldA,myQi) += invJ[d*dim+d2]*gg2(d2,fieldA,myQi);
634                       g3(d,d2,fieldA,myQi) = 0;
635                       for (d3 = 0; d3 < dim; ++d3) {
636                         for (dp = 0; dp < dim; ++dp) {
637                           g3(d,d2,fieldA,myQi) += invJ[d*dim + d3]*gg3(d3,dp,fieldA,myQi)*invJ[d2*dim + dp];
638                         }
639                       }
640                       g3(d,d2,fieldA,myQi) *= wj;
641                     }
642                     g2(d,fieldA,myQi) *= wj;
643                   }
644                 });
645             }); // Nq
646           team.team_barrier();
647           { /* assemble */
648             fieldMats_scr_t s_fieldMats(team.team_scratch(KOKKOS_SHARED_LEVEL),Nb,Nb); // Only used for GPU assembly (ie, not first pass)
649             idx_scr_t       s_idx(team.team_scratch(KOKKOS_SHARED_LEVEL),Nb,nfaces);
650             scale_scr_t     s_scale(team.team_scratch(KOKKOS_SHARED_LEVEL),Nb,nfaces);
651             for (PetscInt fieldA = 0; fieldA < loc_Nf; fieldA++) {
652               /* assemble */
653               Kokkos::parallel_for(Kokkos::TeamThreadRange(team,0,Nb), [=] (int f) {
654                   Kokkos::parallel_for(Kokkos::ThreadVectorRange(team,0,Nb), [=] (int g) {
655                       PetscScalar t = 0;
656                       for (int qj = 0 ; qj < Nq ; qj++) { // look at others integration points
657                         const PetscReal *BJq = &d_BB[qj*Nb], *DIq = &d_DD[qj*Nb*dim];
658                         for (int d = 0; d < dim; ++d) {
659                           t += DIq[f*dim+d]*g2(d,fieldA,qj)*BJq[g];
660                           for (int d2 = 0; d2 < dim; ++d2) {
661                             t += DIq[f*dim + d]*g3(d,d2,fieldA,qj)*DIq[g*dim + d2];
662                           }
663                         }
664                       }
665                       if (elem_mat_num_cells_max_grid) { // CPU assembly
666                         const PetscInt fOff = (fieldA*Nb + f)*totDim + fieldA*Nb + g;
667                         d_elem_mats(b_id,grid,loc_elem,fOff) = t;
668                       } else {
669                         s_fieldMats(f,g) = t;
670                       }
671                     });
672                 });
673               if (!elem_mat_num_cells_max_grid) { // GPU assembly
674                 landau_mat_assemble (d_mat, team, s_fieldMats, s_idx, s_scale, Nb, Nq, nfaces, moffset, loc_elem, fieldA, maps[grid]);
675               }
676             }
677           }
678         } // scope with 'grid'
679       });
680     ierr = PetscLogGpuTimeEnd();CHKERRQ(ierr);
681     ierr = PetscLogEventEnd(events[4],0,0,0,0);CHKERRQ(ierr);
682     if (d_vertex_f_k) delete d_vertex_f_k;
683   } else { // mass
684     ierr = PetscLogEventBegin(events[4],0,0,0,0);CHKERRQ(ierr);
685     ierr = PetscLogGpuTimeBegin();CHKERRQ(ierr);
686     int scr_bytes = fieldMats_scr_t::shmem_size(Nq,Nq) + idx_scr_t::shmem_size(Nb,nfaces) + scale_scr_t::shmem_size(Nb,nfaces);
687     ierr = PetscInfo6(plex[0], "Mass shared memory size: %d bytes in level %d conc=%D team size=%D #face=%D Nb=%D\n",scr_bytes,KOKKOS_SHARED_LEVEL,conc,team_size,nfaces,Nb);CHKERRQ(ierr);
688     Kokkos::parallel_for("Mass", Kokkos::TeamPolicy<>(num_cells_batch*batch_sz, team_size, /* Kokkos::AUTO */ 16).set_scratch_size(KOKKOS_SHARED_LEVEL, Kokkos::PerTeam(scr_bytes)), KOKKOS_LAMBDA (const team_member team) {
689         const PetscInt  b_Nelem = d_elem_offset[num_grids], b_elem_idx = team.league_rank()%b_Nelem, b_id = team.league_rank()/b_Nelem;
690         fieldMats_scr_t s_fieldMats(team.team_scratch(KOKKOS_SHARED_LEVEL),Nb,Nb);
691         idx_scr_t       s_idx(team.team_scratch(KOKKOS_SHARED_LEVEL),Nb,nfaces);
692         scale_scr_t     s_scale(team.team_scratch(KOKKOS_SHARED_LEVEL),Nb,nfaces);
693         // find my grid
694         PetscInt grid = 0;
695         while (b_elem_idx >= d_elem_offset[grid+1]) grid++;
696         {
697           const PetscInt loc_Nf = d_species_offset[grid+1]-d_species_offset[grid], loc_elem = b_elem_idx - d_elem_offset[grid], totDim = loc_Nf*Nq, jpidx_0 = d_ip_offset[grid] + loc_elem * Nq;
698           const PetscInt moffset = LAND_MOFFSET(b_id,grid,batch_sz,num_grids,d_mat_offset);
699           for (int fieldA = 0; fieldA < loc_Nf; fieldA++) {
700             /* assemble */
701             Kokkos::parallel_for(Kokkos::TeamThreadRange(team,0,Nb), [=] (int f) {
702                 Kokkos::parallel_for(Kokkos::ThreadVectorRange(team,0,Nb), [=] (int g) {
703                     PetscScalar    t = 0;
704                     for (int qj = 0 ; qj < Nq ; qj++) { // look at others integration points
705                       const PetscReal *BJq = &d_BB[qj*Nb];
706                       const PetscInt jpidx_glb = jpidx_0 + qj;
707                       if (dim==2) {
708                         t += BJq[f] * d_w_k(jpidx_glb) * shift * BJq[g] * 2. * PETSC_PI;
709                       } else {
710                         t += BJq[f] * d_w_k(jpidx_glb) * shift * BJq[g];
711                       }
712                     }
713                     if (elem_mat_num_cells_max_grid) {
714                       const PetscInt fOff = (fieldA*Nb + f)*totDim + fieldA*Nb + g;
715                       d_elem_mats(b_id,grid,loc_elem,fOff) = t;
716                     } else s_fieldMats(f,g) = t;
717                   });
718               });
719             if (!elem_mat_num_cells_max_grid) { // device assembly
720               landau_mat_assemble (d_mat, team, s_fieldMats, s_idx, s_scale, Nb, Nq, nfaces, moffset, loc_elem, fieldA, maps[grid]);
721             } // else not using GPU assembly
722           }
723         }
724       });
725     ierr = PetscLogGpuTimeEnd();CHKERRQ(ierr);
726     ierr = PetscLogEventEnd(events[4],0,0,0,0);CHKERRQ(ierr);
727   }
728   Kokkos::fence();
729   if (elem_mat_num_cells_max_grid) { // CPU assembly
730     Kokkos::View<PetscScalar****, Kokkos::LayoutRight>::HostMirror h_elem_mats = Kokkos::create_mirror_view(d_elem_mats);
731     Kokkos::deep_copy (h_elem_mats, d_elem_mats);
732     if (container) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "?????");
733     for (PetscInt b_id = 0 ; b_id < batch_sz ; b_id++) { // OpenMP (once)
734       for (PetscInt grid=0 ; grid<num_grids ; grid++) {
735         PetscSection      section, globalSection;
736         PetscInt          cStart,cEnd;
737         Mat               B = subJ[ LAND_PACK_IDX(b_id,grid) ];
738         PetscInt          moffset = LAND_MOFFSET(b_id,grid,batch_sz,num_grids,a_mat_offset), nloc, nzl, colbuf[1024], row;
739         const PetscInt    *cols;
740         const PetscScalar *vals;
741         ierr = PetscLogEventBegin(events[5],0,0,0,0);CHKERRQ(ierr);
742         ierr = DMPlexGetHeightStratum(plex[grid],0,&cStart,&cEnd);CHKERRQ(ierr);
743         ierr = DMGetLocalSection(plex[grid], &section);CHKERRQ(ierr);
744         ierr = DMGetGlobalSection(plex[grid], &globalSection);CHKERRQ(ierr);
745         ierr = PetscLogEventEnd(events[5],0,0,0,0);CHKERRQ(ierr);
746         ierr = PetscLogEventBegin(events[6],0,0,0,0);CHKERRQ(ierr);
747         for (PetscInt ej = cStart ; ej < cEnd; ++ej) {
748           const PetscScalar *elMat = &h_elem_mats(b_id,grid,ej-cStart,0);
749           ierr = DMPlexMatSetClosure(plex[grid], section, globalSection, B, ej, elMat, ADD_VALUES);CHKERRQ(ierr);
750           if (grid==0 && ej==-1) {
751             const PetscInt  loc_Nf = a_species_offset[grid+1]-a_species_offset[grid], totDim = loc_Nf*Nq;
752             int d,f;
753             PetscPrintf(PETSC_COMM_SELF,"Kokkos Element matrix %d/%d\n",1,(int)a_numCells[grid]);
754             for (d = 0; d < totDim; ++d){
755               for (f = 0; f < totDim; ++f) PetscPrintf(PETSC_COMM_SELF," %12.5e",  PetscRealPart(elMat[d*totDim + f]));
756               PetscPrintf(PETSC_COMM_SELF,"\n");
757             }
758             exit(14);
759           }
760         }
761         // move nest matrix to global JacP
762         ierr = MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
763         ierr = MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
764         ierr = MatGetSize(B, &nloc, NULL);CHKERRQ(ierr);
765         for (int i=0 ; i<nloc ; i++) {
766           ierr = MatGetRow(B,i,&nzl,&cols,&vals);CHKERRQ(ierr);
767           if (nzl>1024) SETERRQ1(PetscObjectComm((PetscObject) B), PETSC_ERR_PLIB, "Row too big: %D",nzl);
768           for (int j=0; j<nzl; j++) colbuf[j] = cols[j] + moffset;
769           row = i + moffset;
770           ierr = MatSetValues(JacP,1,&row,nzl,colbuf,vals,ADD_VALUES);CHKERRQ(ierr);
771           ierr = MatRestoreRow(B,i,&nzl,&cols,&vals);CHKERRQ(ierr);
772         }
773         ierr = MatDestroy(&subJ[ LAND_PACK_IDX(b_id,grid) ]);CHKERRQ(ierr);
774         ierr = PetscLogEventEnd(events[6],0,0,0,0);CHKERRQ(ierr);
775       } // grids
776     }
777   }
778   PetscFunctionReturn(0);
779 }
780 } // extern "C"
781