xref: /petsc/src/dm/impls/swarm/tests/ex7.c (revision 2286efddd54511ab18e8e2adb1e023c4bf8f0b92)
1 static char help[] = "Example program demonstrating projection between particle and finite element spaces using OpenMP in 2D cylindrical coordinates\n";
2 
3 #include <petscdmplex.h>
4 #include <petscds.h>
5 #include <petscdmswarm.h>
6 #include <petscksp.h>
7 #include <petsc/private/petscimpl.h>
8 #if defined(PETSC_HAVE_OPENMP) && defined(PETSC_HAVE_THREADSAFETY)
9   #include <omp.h>
10 #endif
11 
12 typedef struct {
13   Mat MpTrans;
14   Mat Mp;
15   Vec ff;
16   Vec uu;
17 } MatShellCtx;
18 
MatMultMtM_SeqAIJ(Mat MtM,Vec xx,Vec yy)19 PetscErrorCode MatMultMtM_SeqAIJ(Mat MtM, Vec xx, Vec yy)
20 {
21   MatShellCtx *matshellctx;
22 
23   PetscFunctionBeginUser;
24   PetscCall(MatShellGetContext(MtM, &matshellctx));
25   PetscCheck(matshellctx, PETSC_COMM_WORLD, PETSC_ERR_ARG_OUTOFRANGE, "No context");
26   PetscCall(MatMult(matshellctx->Mp, xx, matshellctx->ff));
27   PetscCall(MatMult(matshellctx->MpTrans, matshellctx->ff, yy));
28   PetscFunctionReturn(PETSC_SUCCESS);
29 }
30 
MatMultAddMtM_SeqAIJ(Mat MtM,Vec xx,Vec yy,Vec zz)31 PetscErrorCode MatMultAddMtM_SeqAIJ(Mat MtM, Vec xx, Vec yy, Vec zz)
32 {
33   MatShellCtx *matshellctx;
34 
35   PetscFunctionBeginUser;
36   PetscCall(MatShellGetContext(MtM, &matshellctx));
37   PetscCheck(matshellctx, PETSC_COMM_WORLD, PETSC_ERR_ARG_OUTOFRANGE, "No context");
38   PetscCall(MatMult(matshellctx->Mp, xx, matshellctx->ff));
39   PetscCall(MatMultAdd(matshellctx->MpTrans, matshellctx->ff, yy, zz));
40   PetscFunctionReturn(PETSC_SUCCESS);
41 }
42 
createSwarm(const DM dm,DM * sw)43 PetscErrorCode createSwarm(const DM dm, DM *sw)
44 {
45   PetscInt Nc = 1, dim = 2;
46 
47   PetscFunctionBeginUser;
48   PetscCall(DMCreate(PETSC_COMM_SELF, sw));
49   PetscCall(DMSetType(*sw, DMSWARM));
50   PetscCall(DMSetDimension(*sw, dim));
51   PetscCall(DMSwarmSetType(*sw, DMSWARM_PIC));
52   PetscCall(DMSwarmSetCellDM(*sw, dm));
53   PetscCall(DMSwarmRegisterPetscDatatypeField(*sw, "w_q", Nc, PETSC_SCALAR));
54   PetscCall(DMSwarmFinalizeFieldRegister(*sw));
55   PetscCall(DMSetFromOptions(*sw));
56   PetscFunctionReturn(PETSC_SUCCESS);
57 }
58 
gridToParticles(const DM dm,DM sw,PetscReal * moments,Vec rhs,Mat M_p)59 PetscErrorCode gridToParticles(const DM dm, DM sw, PetscReal *moments, Vec rhs, Mat M_p)
60 {
61   PetscBool     is_lsqr;
62   KSP           ksp;
63   Mat           PM_p = NULL, MtM, D;
64   Vec           ff;
65   PetscInt      Np, timestep = 0, bs, N, M, nzl;
66   PetscReal     time = 0.0;
67   PetscDataType dtype;
68   MatShellCtx  *matshellctx;
69 
70   PetscFunctionBeginUser;
71   PetscCall(KSPCreate(PETSC_COMM_SELF, &ksp));
72   PetscCall(KSPSetOptionsPrefix(ksp, "ftop_"));
73   PetscCall(KSPSetFromOptions(ksp));
74   PetscCall(PetscObjectTypeCompare((PetscObject)ksp, KSPLSQR, &is_lsqr));
75   if (!is_lsqr) {
76     PetscCall(MatGetLocalSize(M_p, &M, &N));
77     if (N > M) {
78       PC pc;
79       PetscCall(PetscInfo(ksp, " M (%" PetscInt_FMT ") < N (%" PetscInt_FMT ") -- skip revert to lsqr\n", M, N));
80       is_lsqr = PETSC_TRUE;
81       PetscCall(KSPSetType(ksp, KSPLSQR));
82       PetscCall(KSPGetPC(ksp, &pc));
83       PetscCall(PCSetType(pc, PCNONE)); // could put in better solver -ftop_pc_type bjacobi -ftop_sub_pc_type lu -ftop_sub_pc_factor_shift_type nonzero
84     } else {
85       PetscCall(PetscNew(&matshellctx));
86       PetscCall(MatCreateShell(PetscObjectComm((PetscObject)dm), N, N, PETSC_DECIDE, PETSC_DECIDE, matshellctx, &MtM));
87       PetscCall(MatTranspose(M_p, MAT_INITIAL_MATRIX, &matshellctx->MpTrans));
88       matshellctx->Mp = M_p;
89       PetscCall(MatShellSetOperation(MtM, MATOP_MULT, (PetscErrorCodeFn *)MatMultMtM_SeqAIJ));
90       PetscCall(MatShellSetOperation(MtM, MATOP_MULT_ADD, (PetscErrorCodeFn *)MatMultAddMtM_SeqAIJ));
91       PetscCall(MatCreateVecs(M_p, &matshellctx->uu, &matshellctx->ff));
92       PetscCall(MatCreateSeqAIJ(PETSC_COMM_SELF, N, N, 1, NULL, &D));
93       for (int i = 0; i < N; i++) {
94         const PetscScalar *vals;
95         const PetscInt    *cols;
96         PetscScalar        dot = 0;
97         PetscCall(MatGetRow(matshellctx->MpTrans, i, &nzl, &cols, &vals));
98         for (int ii = 0; ii < nzl; ii++) dot += PetscSqr(vals[ii]);
99         PetscCheck(dot != 0.0, PETSC_COMM_WORLD, PETSC_ERR_ARG_OUTOFRANGE, "Row %d is empty", i);
100         PetscCall(MatSetValue(D, i, i, dot, INSERT_VALUES));
101       }
102       PetscCall(MatAssemblyBegin(D, MAT_FINAL_ASSEMBLY));
103       PetscCall(MatAssemblyEnd(D, MAT_FINAL_ASSEMBLY));
104       PetscCall(PetscInfo(M_p, "createMtMKSP Have %" PetscInt_FMT " eqs, nzl = %" PetscInt_FMT "\n", N, nzl));
105       PetscCall(KSPSetOperators(ksp, MtM, D));
106       PetscCall(MatViewFromOptions(D, NULL, "-ftop2_D_mat_view"));
107       PetscCall(MatViewFromOptions(M_p, NULL, "-ftop2_Mp_mat_view"));
108       PetscCall(MatViewFromOptions(matshellctx->MpTrans, NULL, "-ftop2_MpTranspose_mat_view"));
109     }
110   }
111   if (is_lsqr) {
112     PC        pc;
113     PetscBool is_bjac;
114     PetscCall(KSPGetPC(ksp, &pc));
115     PetscCall(PetscObjectTypeCompare((PetscObject)pc, PCBJACOBI, &is_bjac));
116     if (is_bjac) {
117       PetscCall(DMSwarmCreateMassMatrixSquare(sw, dm, &PM_p));
118       PetscCall(KSPSetOperators(ksp, M_p, PM_p));
119     } else {
120       PetscCall(KSPSetOperators(ksp, M_p, M_p));
121     }
122   }
123   PetscCall(DMSwarmCreateGlobalVectorFromField(sw, "w_q", &ff)); // this grabs access !!!!!
124   if (!is_lsqr) {
125     PetscCall(KSPSolve(ksp, rhs, matshellctx->uu));
126     PetscCall(MatMult(M_p, matshellctx->uu, ff));
127     PetscCall(MatDestroy(&matshellctx->MpTrans));
128     PetscCall(VecDestroy(&matshellctx->ff));
129     PetscCall(VecDestroy(&matshellctx->uu));
130     PetscCall(MatDestroy(&D));
131     PetscCall(MatDestroy(&MtM));
132     PetscCall(PetscFree(matshellctx));
133   } else {
134     PetscCall(KSPSolveTranspose(ksp, rhs, ff));
135   }
136   PetscCall(KSPDestroy(&ksp));
137   /* Visualize particle field */
138   PetscCall(DMSetOutputSequenceNumber(sw, timestep, time));
139   PetscCall(VecViewFromOptions(ff, NULL, "-weights_view"));
140   PetscCall(DMSwarmDestroyGlobalVectorFromField(sw, "w_q", &ff));
141 
142   /* compute energy */
143   if (moments) {
144     PetscReal *wq, *coords;
145     PetscCall(DMSwarmGetLocalSize(sw, &Np));
146     PetscCall(DMSwarmGetField(sw, "w_q", &bs, &dtype, (void **)&wq));
147     PetscCall(DMSwarmGetField(sw, "DMSwarmPIC_coor", &bs, &dtype, (void **)&coords));
148     moments[0] = moments[1] = moments[2] = 0;
149     for (int p = 0; p < Np; p++) {
150       moments[0] += wq[p];
151       moments[1] += wq[p] * coords[p * 2 + 0]; // x-momentum
152       moments[2] += wq[p] * (PetscSqr(coords[p * 2 + 0]) + PetscSqr(coords[p * 2 + 1]));
153     }
154     PetscCall(DMSwarmRestoreField(sw, "DMSwarmPIC_coor", &bs, &dtype, (void **)&coords));
155     PetscCall(DMSwarmRestoreField(sw, "w_q", &bs, &dtype, (void **)&wq));
156   }
157   PetscCall(MatDestroy(&PM_p));
158   PetscFunctionReturn(PETSC_SUCCESS);
159 }
160 
particlesToGrid(const DM dm,DM sw,const PetscInt Np,const PetscInt a_tid,const PetscInt dim,const PetscInt target,const PetscReal xx[],const PetscReal yy[],const PetscReal a_wp[],Vec rho,Mat * Mp_out)161 PetscErrorCode particlesToGrid(const DM dm, DM sw, const PetscInt Np, const PetscInt a_tid, const PetscInt dim, const PetscInt target, const PetscReal xx[], const PetscReal yy[], const PetscReal a_wp[], Vec rho, Mat *Mp_out)
162 {
163   PetscBool     removePoints = PETSC_TRUE;
164   PetscReal    *wq, *coords;
165   PetscDataType dtype;
166   Mat           M_p;
167   Vec           ff;
168   PetscInt      bs, p, zero = 0;
169 
170   PetscFunctionBeginUser;
171   PetscCall(DMSwarmSetLocalSizes(sw, Np, zero));
172   PetscCall(DMSwarmGetField(sw, "w_q", &bs, &dtype, (void **)&wq));
173   PetscCall(DMSwarmGetField(sw, "DMSwarmPIC_coor", &bs, &dtype, (void **)&coords));
174   for (p = 0; p < Np; p++) {
175     coords[p * 2 + 0] = xx[p];
176     coords[p * 2 + 1] = yy[p];
177     wq[p]             = a_wp[p];
178   }
179   PetscCall(DMSwarmRestoreField(sw, "DMSwarmPIC_coor", &bs, &dtype, (void **)&coords));
180   PetscCall(DMSwarmRestoreField(sw, "w_q", &bs, &dtype, (void **)&wq));
181   PetscCall(DMSwarmMigrate(sw, removePoints));
182   PetscCall(PetscObjectSetName((PetscObject)sw, "Particle Grid"));
183   if (a_tid == target) PetscCall(DMViewFromOptions(sw, NULL, "-swarm_view"));
184 
185   /* Project particles to field */
186   /* This gives M f = \int_\Omega \phi f, which looks like a rhs for a PDE */
187   PetscCall(DMCreateMassMatrix(sw, dm, &M_p));
188   PetscCall(PetscObjectSetName((PetscObject)rho, "rho"));
189 
190   PetscCall(DMSwarmCreateGlobalVectorFromField(sw, "w_q", &ff)); // this grabs access !!!!!
191   PetscCall(PetscObjectSetName((PetscObject)ff, "weights"));
192   PetscCall(MatMultTranspose(M_p, ff, rho));
193   PetscCall(DMSwarmDestroyGlobalVectorFromField(sw, "w_q", &ff));
194 
195   /* Visualize mesh field */
196   if (a_tid == target) PetscCall(VecViewFromOptions(rho, NULL, "-rho_view"));
197   // output
198   *Mp_out = M_p;
199   PetscFunctionReturn(PETSC_SUCCESS);
200 }
201 
maxwellian(PetscInt dim,const PetscReal x[],PetscReal kt_m,PetscReal n,PetscScalar * u)202 static PetscErrorCode maxwellian(PetscInt dim, const PetscReal x[], PetscReal kt_m, PetscReal n, PetscScalar *u)
203 {
204   PetscInt  i;
205   PetscReal v2 = 0, theta = 2 * kt_m; /* theta = 2kT/mc^2 */
206 
207   PetscFunctionBegin;
208   /* compute the exponents, v^2 */
209   for (i = 0; i < dim; ++i) v2 += x[i] * x[i];
210   /* evaluate the Maxwellian */
211   u[0] = n * PetscPowReal(PETSC_PI * theta, -1.5) * (PetscExpReal(-v2 / theta)) * 2. * PETSC_PI * x[1]; // radial term for 2D axi-sym.
212   PetscFunctionReturn(PETSC_SUCCESS);
213 }
214 
215 #define MAX_NUM_THRDS 12
go()216 PetscErrorCode go()
217 {
218   DM            dm_t[MAX_NUM_THRDS], sw_t[MAX_NUM_THRDS];
219   PetscFE       fe;
220   PetscInt      dim = 2, Nc = 1, i, faces[3];
221   PetscInt      Np[2] = {10, 10}, Np2[2], field = 0, target = 0, Np_t[MAX_NUM_THRDS];
222   PetscReal     moments_0[3], moments_1[3], vol = 1;
223   PetscReal     lo[3] = {-5, 0, -5}, hi[3] = {5, 5, 5}, h[3], hp[3], *xx_t[MAX_NUM_THRDS], *yy_t[MAX_NUM_THRDS], *wp_t[MAX_NUM_THRDS];
224   Vec           rho_t[MAX_NUM_THRDS], rhs_t[MAX_NUM_THRDS];
225   Mat           M_p_t[MAX_NUM_THRDS];
226   PetscLogStage stage;
227   PetscLogEvent swarm_create_ev, solve_ev, solve_loop_ev;
228 #if defined(PETSC_HAVE_OPENMP) && defined(PETSC_HAVE_THREADSAFETY)
229   PetscInt numthreads = PetscNumOMPThreads;
230 #else
231   PetscInt numthreads = 1;
232 #endif
233 
234   PetscFunctionBeginUser;
235 #if defined(PETSC_HAVE_OPENMP) && defined(PETSC_HAVE_THREADSAFETY)
236   PetscCheck(numthreads <= MAX_NUM_THRDS, PETSC_COMM_WORLD, PETSC_ERR_ARG_OUTOFRANGE, "Too many threads %" PetscInt_FMT " > %d", numthreads, MAX_NUM_THRDS);
237   PetscCheck(numthreads > 0, PETSC_COMM_WORLD, PETSC_ERR_ARG_OUTOFRANGE, "No threads %" PetscInt_FMT " > %d", numthreads, MAX_NUM_THRDS);
238 #endif
239   if (target >= numthreads) target = numthreads - 1;
240   PetscCall(PetscLogEventRegister("Create Swarm", DM_CLASSID, &swarm_create_ev));
241   PetscCall(PetscLogEventRegister("Single solve", DM_CLASSID, &solve_ev));
242   PetscCall(PetscLogEventRegister("Solve loop", DM_CLASSID, &solve_loop_ev));
243   PetscCall(PetscLogStageRegister("Solve", &stage));
244   i = dim;
245   PetscCall(PetscOptionsGetIntArray(NULL, NULL, "-dm_plex_box_faces", faces, &i, NULL));
246   i = dim;
247   PetscCall(PetscOptionsGetIntArray(NULL, NULL, "-np", Np, &i, NULL));
248   /* Create thread meshes */
249   for (int tid = 0; tid < numthreads; tid++) {
250     PetscBool simplex = PETSC_FALSE;
251     PetscCall(PetscOptionsGetBool(NULL, NULL, "-dm_plex_simplex", &simplex, NULL));
252     // setup mesh dm_t, could use PETSc's Landau create velocity space mesh here to get dm_t[tid]
253     PetscCall(DMCreate(PETSC_COMM_SELF, &dm_t[tid]));
254     PetscCall(DMSetType(dm_t[tid], DMPLEX));
255     PetscCall(DMSetFromOptions(dm_t[tid]));
256     PetscCall(PetscFECreateDefault(PETSC_COMM_SELF, dim, Nc, simplex, "", PETSC_DECIDE, &fe));
257     PetscCall(PetscFESetFromOptions(fe));
258     PetscCall(PetscObjectSetName((PetscObject)fe, "fe"));
259     PetscCall(DMSetField(dm_t[tid], field, NULL, (PetscObject)fe));
260     PetscCall(DMCreateDS(dm_t[tid]));
261     PetscCall(PetscFEDestroy(&fe));
262     // helper vectors
263     PetscCall(DMCreateGlobalVector(dm_t[tid], &rho_t[tid]));
264     PetscCall(DMCreateGlobalVector(dm_t[tid], &rhs_t[tid]));
265     // this mimics application code
266     PetscCall(DMGetBoundingBox(dm_t[tid], lo, hi));
267     if (tid == target) {
268       PetscCall(DMViewFromOptions(dm_t[tid], NULL, "-dm_view"));
269       for (i = 0, vol = 1; i < dim; i++) {
270         h[i]  = (hi[i] - lo[i]) / faces[i];
271         hp[i] = (hi[i] - lo[i]) / Np[i];
272         vol *= (hi[i] - lo[i]);
273         PetscCall(PetscInfo(dm_t[tid], " lo = %g hi = %g n = %" PetscInt_FMT " h = %g hp = %g\n", (double)lo[i], (double)hi[i], faces[i], (double)h[i], (double)hp[i]));
274         (void)h[i];
275       }
276     }
277   }
278   // prepare particle data for problems. This mimics application code
279   PetscCall(PetscLogEventBegin(swarm_create_ev, 0, 0, 0, 0));
280   Np2[0] = Np[0];
281   Np2[1] = Np[1];
282   for (int tid = 0; tid < numthreads; tid++) { // change size of particle list a little
283     Np_t[tid] = Np2[0] * Np2[1];
284     PetscCall(PetscMalloc3(Np_t[tid], &xx_t[tid], Np_t[tid], &yy_t[tid], Np_t[tid], &wp_t[tid]));
285     if (tid == target) moments_0[0] = moments_0[1] = moments_0[2] = 0;
286     for (int pi = 0, pp = 0; pi < Np2[0]; pi++) {
287       for (int pj = 0; pj < Np2[1]; pj++, pp++) {
288         xx_t[tid][pp] = lo[0] + hp[0] / 2. + pi * hp[0];
289         yy_t[tid][pp] = lo[1] + hp[1] / 2. + pj * hp[1];
290         {
291           PetscReal x[] = {xx_t[tid][pp], yy_t[tid][pp]};
292           PetscCall(maxwellian(2, x, 1.0, vol / (PetscReal)Np_t[tid], &wp_t[tid][pp]));
293         }
294         if (tid == target) { //energy_0 += wp_t[tid][pp]*(PetscSqr(xx_t[tid][pp])+PetscSqr(yy_t[tid][pp]));
295           moments_0[0] += wp_t[tid][pp];
296           moments_0[1] += wp_t[tid][pp] * xx_t[tid][pp]; // x-momentum
297           moments_0[2] += wp_t[tid][pp] * (PetscSqr(xx_t[tid][pp]) + PetscSqr(yy_t[tid][pp]));
298         }
299       }
300     }
301     Np2[0]++;
302     Np2[1]++;
303   }
304   PetscCall(PetscLogEventEnd(swarm_create_ev, 0, 0, 0, 0));
305   PetscCall(PetscLogEventBegin(solve_ev, 0, 0, 0, 0));
306   /* Create particle swarm */
307   PetscPragmaOMP(parallel for)
308   for (int tid = 0; tid < numthreads; tid++) PetscCallAbort(PETSC_COMM_SELF, createSwarm(dm_t[tid], &sw_t[tid]));
309   PetscPragmaOMP(parallel for)
310   for (int tid = 0; tid < numthreads; tid++) PetscCallAbort(PETSC_COMM_SELF, particlesToGrid(dm_t[tid], sw_t[tid], Np_t[tid], tid, dim, target, xx_t[tid], yy_t[tid], wp_t[tid], rho_t[tid], &M_p_t[tid]));
311   /* Project field to particles */
312   /*   This gives f_p = M_p^+ M f */
313   PetscPragmaOMP(parallel for)
314   for (int tid = 0; tid < numthreads; tid++) PetscCallAbort(PETSC_COMM_SELF, VecCopy(rho_t[tid], rhs_t[tid])); /* Identity: M^1 M rho */
315   PetscPragmaOMP(parallel for)
316   for (int tid = 0; tid < numthreads; tid++) PetscCallAbort(PETSC_COMM_SELF, gridToParticles(dm_t[tid], sw_t[tid], (tid == target) ? moments_1 : NULL, rhs_t[tid], M_p_t[tid]));
317   /* Cleanup */
318   for (int tid = 0; tid < numthreads; tid++) {
319     PetscCall(MatDestroy(&M_p_t[tid]));
320     PetscCall(DMDestroy(&sw_t[tid]));
321   }
322   PetscCall(PetscLogEventEnd(solve_ev, 0, 0, 0, 0));
323   //
324   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Total number density: %20.12e (%20.12e); x-momentum = %g (%g); energy = %g error = %e, %" PetscInt_FMT " particles. Use %" PetscInt_FMT " threads\n", (double)moments_1[0], (double)moments_0[0], (double)moments_1[1], (double)moments_0[1], (double)moments_1[2], (double)((moments_1[2] - moments_0[2]) / moments_0[2]), Np[0] * Np[1], numthreads));
325   /* Cleanup */
326   for (int tid = 0; tid < numthreads; tid++) {
327     PetscCall(VecDestroy(&rho_t[tid]));
328     PetscCall(VecDestroy(&rhs_t[tid]));
329     PetscCall(DMDestroy(&dm_t[tid]));
330     PetscCall(PetscFree3(xx_t[tid], yy_t[tid], wp_t[tid]));
331   }
332   PetscFunctionReturn(PETSC_SUCCESS);
333 }
334 
main(int argc,char ** argv)335 int main(int argc, char **argv)
336 {
337   PetscFunctionBeginUser;
338 #if defined(PETSC_HAVE_OPENMP) && defined(PETSC_HAVE_THREADSAFETY)
339   PETSC_MPI_THREAD_REQUIRED = MPI_THREAD_MULTIPLE; // use thread multiple if multiple threads call petsc
340 #endif
341   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
342   PetscCall(go());
343   PetscCall(PetscFinalize());
344   return 0;
345 }
346 
347 /*TEST
348 
349   build:
350     requires: !complex
351 
352   test:
353     suffix: 0
354     requires: double triangle
355     args: -dm_plex_simplex 0 -dm_plex_box_faces 8,4 -np 10,10 -dm_plex_box_lower -2.0,0.0 -dm_plex_box_upper 2.0,2.0 -petscspace_degree 2 -ftop_ksp_type lsqr -ftop_pc_type none -dm_view -ftop_ksp_converged_reason -ftop_ksp_rtol 1.e-14
356     filter: grep -v DM_ | grep -v atomic
357     TODO: broken due to thread safety problems
358 
359   test:
360     suffix: 1
361     requires: double triangle
362     args: -dm_plex_simplex 0 -dm_plex_box_faces 8,4 -np 10,10 -dm_plex_box_lower -2.0,0.0 -dm_plex_box_upper 2.0,2.0 -petscspace_degree 2 -dm_plex_hash_location -ftop_ksp_type lsqr -ftop_pc_type bjacobi -ftop_sub_pc_type lu -ftop_sub_pc_factor_shift_type nonzero -dm_view -ftop_ksp_converged_reason -ftop_ksp_rtol 1.e-14
363     filter: grep -v DM_ | grep -v atomic
364     TODO: broken due to thread safety problems
365 
366   test:
367     suffix: 2
368     requires: double triangle
369     args: -dm_plex_simplex 1 -dm_plex_box_faces 8,4 -np 15,15 -dm_plex_box_lower -2.0,0.0 -dm_plex_box_upper 2.0,2.0 -petscspace_degree 2 -ftop_ksp_type cg -ftop_pc_type jacobi -dm_view -ftop_ksp_converged_reason -ftop_ksp_rtol 1.e-14
370     filter: grep -v DM_ | grep -v atomic
371     TODO: broken due to thread safety problems
372 
373 TEST*/
374