1 2 #include <petsc/private/matimpl.h> 3 #include <petsc/private/pcimpl.h> 4 #include <petsc/private/dmimpl.h> 5 #include <petscksp.h> /*I "petscksp.h" I*/ 6 #include <petscdm.h> 7 #include <petscdmda.h> 8 #include <petscdmshell.h> 9 10 #include "../src/ksp/pc/impls/telescope/telescope.h" 11 12 static PetscBool cited = PETSC_FALSE; 13 static const char citation[] = 14 "@inproceedings{MaySananRuppKnepleySmith2016,\n" 15 " title = {Extreme-Scale Multigrid Components within PETSc},\n" 16 " author = {Dave A. May and Patrick Sanan and Karl Rupp and Matthew G. Knepley and Barry F. Smith},\n" 17 " booktitle = {Proceedings of the Platform for Advanced Scientific Computing Conference},\n" 18 " series = {PASC '16},\n" 19 " isbn = {978-1-4503-4126-4},\n" 20 " location = {Lausanne, Switzerland},\n" 21 " pages = {5:1--5:12},\n" 22 " articleno = {5},\n" 23 " numpages = {12},\n" 24 " url = {http://doi.acm.org/10.1145/2929908.2929913},\n" 25 " doi = {10.1145/2929908.2929913},\n" 26 " acmid = {2929913},\n" 27 " publisher = {ACM},\n" 28 " address = {New York, NY, USA},\n" 29 " keywords = {GPU, HPC, agglomeration, coarse-level solver, multigrid, parallel computing, preconditioning},\n" 30 " year = {2016}\n" 31 "}\n"; 32 33 typedef struct { 34 DM dm_fine,dm_coarse; /* these DM's should be topologically identical but use different communicators */ 35 Mat permutation; 36 Vec xp; 37 PetscErrorCode (*fp_dm_field_scatter)(DM,Vec,ScatterMode,DM,Vec); 38 PetscErrorCode (*fp_dm_state_scatter)(DM,ScatterMode,DM); 39 void *dmksp_context_determined; 40 void *dmksp_context_user; 41 } PC_Telescope_CoarseDMCtx; 42 43 44 PetscErrorCode PCTelescopeSetUp_scatters_CoarseDM(PC pc,PC_Telescope sred,PC_Telescope_CoarseDMCtx *ctx) 45 { 46 PetscErrorCode ierr; 47 Vec xred,yred,xtmp,x,xp; 48 VecScatter scatter; 49 IS isin; 50 Mat B; 51 PetscInt m,bs,st,ed; 52 MPI_Comm comm; 53 54 PetscFunctionBegin; 55 ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr); 56 ierr = PCGetOperators(pc,NULL,&B);CHKERRQ(ierr); 57 ierr = MatCreateVecs(B,&x,NULL);CHKERRQ(ierr); 58 ierr = MatGetBlockSize(B,&bs);CHKERRQ(ierr); 59 ierr = VecDuplicate(x,&xp);CHKERRQ(ierr); 60 m = 0; 61 xred = NULL; 62 yred = NULL; 63 if (PCTelescope_isActiveRank(sred)) { 64 ierr = DMCreateGlobalVector(ctx->dm_coarse,&xred);CHKERRQ(ierr); 65 ierr = VecDuplicate(xred,&yred);CHKERRQ(ierr); 66 ierr = VecGetOwnershipRange(xred,&st,&ed);CHKERRQ(ierr); 67 ierr = ISCreateStride(comm,ed-st,st,1,&isin);CHKERRQ(ierr); 68 ierr = VecGetLocalSize(xred,&m);CHKERRQ(ierr); 69 } else { 70 ierr = VecGetOwnershipRange(x,&st,&ed);CHKERRQ(ierr); 71 ierr = ISCreateStride(comm,0,st,1,&isin);CHKERRQ(ierr); 72 } 73 ierr = ISSetBlockSize(isin,bs);CHKERRQ(ierr); 74 ierr = VecCreate(comm,&xtmp);CHKERRQ(ierr); 75 ierr = VecSetSizes(xtmp,m,PETSC_DECIDE);CHKERRQ(ierr); 76 ierr = VecSetBlockSize(xtmp,bs);CHKERRQ(ierr); 77 ierr = VecSetType(xtmp,((PetscObject)x)->type_name);CHKERRQ(ierr); 78 ierr = VecScatterCreate(x,isin,xtmp,NULL,&scatter);CHKERRQ(ierr); 79 sred->xred = xred; 80 sred->yred = yred; 81 sred->isin = isin; 82 sred->scatter = scatter; 83 sred->xtmp = xtmp; 84 ctx->xp = xp; 85 ierr = VecDestroy(&x);CHKERRQ(ierr); 86 PetscFunctionReturn(0); 87 } 88 89 PetscErrorCode PCTelescopeSetUp_CoarseDM(PC pc,PC_Telescope sred) 90 { 91 PC_Telescope_CoarseDMCtx *ctx; 92 DM dm,dm_coarse = NULL; 93 MPI_Comm comm; 94 PetscBool has_perm,has_kspcomputeoperators,using_kspcomputeoperators; 95 PetscErrorCode ierr; 96 97 PetscFunctionBegin; 98 ierr = PetscInfo(pc,"PCTelescope: setup (CoarseDM)\n");CHKERRQ(ierr); 99 ierr = PetscMalloc1(1,&ctx);CHKERRQ(ierr); 100 ierr = PetscMemzero(ctx,sizeof(PC_Telescope_CoarseDMCtx));CHKERRQ(ierr); 101 sred->dm_ctx = (void*)ctx; 102 103 ierr = PetscObjectGetComm((PetscObject)pc,&comm);CHKERRQ(ierr); 104 ierr = PCGetDM(pc,&dm);CHKERRQ(ierr); 105 ierr = DMGetCoarseDM(dm,&dm_coarse);CHKERRQ(ierr); 106 ctx->dm_fine = dm; 107 ctx->dm_coarse = dm_coarse; 108 109 /* attach coarse dm to ksp on sub communicator */ 110 if (PCTelescope_isActiveRank(sred)) { 111 ierr = KSPSetDM(sred->ksp,ctx->dm_coarse);CHKERRQ(ierr); 112 if (sred->ignore_kspcomputeoperators) { 113 ierr = KSPSetDMActive(sred->ksp,PETSC_FALSE);CHKERRQ(ierr); 114 } 115 } 116 117 /* check if there is a method to provide a permutation */ 118 has_perm = PETSC_FALSE; 119 has_kspcomputeoperators = PETSC_FALSE; 120 using_kspcomputeoperators = PETSC_FALSE; 121 122 /* if no permutation is provided, we must rely on KSPSetComputeOperators */ 123 { 124 PetscErrorCode (*dmfine_kspfunc)(KSP,Mat,Mat,void*) = NULL; 125 void *dmfine_kspctx = NULL,*dmcoarse_kspctx = NULL; 126 void *dmfine_appctx = NULL,*dmcoarse_appctx = NULL; 127 void *dmfine_shellctx = NULL,*dmcoarse_shellctx = NULL; 128 129 ierr = DMKSPGetComputeOperators(dm,&dmfine_kspfunc,&dmfine_kspctx);CHKERRQ(ierr); 130 if (dmfine_kspfunc) { has_kspcomputeoperators = PETSC_TRUE; } 131 132 ierr = DMGetApplicationContext(ctx->dm_fine,&dmfine_appctx);CHKERRQ(ierr); 133 ierr = DMShellGetContext(ctx->dm_fine,&dmfine_shellctx);CHKERRQ(ierr); 134 135 /* need to define dmcoarse_kspctx */ 136 if (dmfine_kspfunc && !sred->ignore_kspcomputeoperators) { 137 138 ierr = PetscInfo(pc,"PCTelescope: KSPSetComputeOperators fetched from parent DM\n");CHKERRQ(ierr); 139 if (PCTelescope_isActiveRank(sred)) { 140 ierr = DMGetApplicationContext(ctx->dm_coarse,&dmcoarse_appctx);CHKERRQ(ierr); 141 ierr = DMShellGetContext(ctx->dm_coarse,&dmcoarse_shellctx);CHKERRQ(ierr); 142 } 143 144 /* Assume that if the fine operator didn't require any context, neither will the coarse */ 145 if (!dmfine_kspctx) { 146 dmcoarse_kspctx = NULL; 147 ierr = PetscInfo(pc,"PCTelescope: KSPSetComputeOperators using NULL context\n");CHKERRQ(ierr); 148 } else { 149 150 ierr = PetscInfo(pc,"PCTelescope: KSPSetComputeOperators detected non-NULL context from parent DM \n");CHKERRQ(ierr); 151 if (PCTelescope_isActiveRank(sred)) { 152 153 if (dmfine_kspctx == dmfine_appctx) { 154 dmcoarse_kspctx = dmcoarse_appctx; 155 ierr = PetscInfo(pc,"PCTelescope: KSPSetComputeOperators using context from DM->ApplicationContext\n");CHKERRQ(ierr); 156 if (!dmcoarse_kspctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Non NULL dmfine->kspctx == dmfine->appctx. NULL dmcoarse->appctx found. Likely this is an error"); 157 } else if (dmfine_kspctx == dmfine_shellctx) { 158 dmcoarse_kspctx = dmcoarse_shellctx; 159 ierr = PetscInfo(pc,"PCTelescope: KSPSetComputeOperators using context from DMShell->Context\n");CHKERRQ(ierr); 160 if (!dmcoarse_kspctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Non NULL dmfine->kspctx == dmfine.shell->ctx. NULL dmcoarse.shell->ctx found. Likely this is an error"); 161 } 162 ctx->dmksp_context_determined = dmcoarse_kspctx; 163 164 /* look for user provided method to fetch the context */ 165 { 166 PetscErrorCode (*fp_get_coarsedm_context)(DM,void**) = NULL; 167 void *dmcoarse_context_user = NULL; 168 char dmcoarse_method[PETSC_MAX_PATH_LEN]; 169 170 ierr = PetscSNPrintf(dmcoarse_method,sizeof(dmcoarse_method),"PCTelescopeGetCoarseDMKSPContext");CHKERRQ(ierr); 171 ierr = PetscObjectQueryFunction((PetscObject)ctx->dm_coarse,dmcoarse_method,&fp_get_coarsedm_context);CHKERRQ(ierr); 172 if (fp_get_coarsedm_context) { 173 ierr = PetscInfo(pc,"PCTelescope: Found composed method PCTelescopeGetCoarseDMKSPContext from coarse DM\n");CHKERRQ(ierr); 174 ierr = fp_get_coarsedm_context(ctx->dm_coarse,&dmcoarse_context_user);CHKERRQ(ierr); 175 ctx->dmksp_context_user = dmcoarse_context_user; 176 dmcoarse_kspctx = dmcoarse_context_user; 177 } else { 178 ierr = PetscInfo(pc,"PCTelescope: Failed to find composed method PCTelescopeGetCoarseDMKSPContext from coarse DM\n");CHKERRQ(ierr); 179 } 180 } 181 182 if (!dmcoarse_kspctx) { 183 ierr = PetscInfo(pc,"PCTelescope: KSPSetComputeOperators failed to determine the context to use on sub-communicator\n");CHKERRQ(ierr); 184 SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"Cannot determine which context with use for KSPSetComputeOperators() on sub-communicator"); 185 } 186 } 187 } 188 } 189 190 if (dmfine_kspfunc && !sred->ignore_kspcomputeoperators) { 191 using_kspcomputeoperators = PETSC_TRUE; 192 193 if (PCTelescope_isActiveRank(sred)) { 194 /* sub ksp inherits dmksp_func and context provided by user */ 195 ierr = KSPSetComputeOperators(sred->ksp,dmfine_kspfunc,dmcoarse_kspctx);CHKERRQ(ierr); 196 /*ierr = PetscObjectCopyFortranFunctionPointers((PetscObject)dm,(PetscObject)ctx->dmrepart);CHKERRQ(ierr);*/ 197 ierr = KSPSetDMActive(sred->ksp,PETSC_TRUE);CHKERRQ(ierr); 198 } 199 } 200 } 201 202 if (!has_perm && has_kspcomputeoperators && !using_kspcomputeoperators) SETERRQ(comm,PETSC_ERR_SUP,"No method to permute an operator was found on the parent DM. A method for KSPSetComputeOperators() was provided but it was requested to be ignored. Telescope setup cannot proceed"); 203 if (!has_perm && !has_kspcomputeoperators) SETERRQ(comm,PETSC_ERR_SUP,"No method to permute an operator was found on the parent DM. No method for KSPSetComputeOperators() was provided. Telescope setup cannot proceed"); 204 205 { 206 char dmfine_method[PETSC_MAX_PATH_LEN]; 207 208 ierr = PetscSNPrintf(dmfine_method,sizeof(dmfine_method),"PCTelescopeFieldScatter");CHKERRQ(ierr); 209 ierr = PetscObjectQueryFunction((PetscObject)ctx->dm_fine,dmfine_method,&ctx->fp_dm_field_scatter);CHKERRQ(ierr); 210 211 ierr = PetscSNPrintf(dmfine_method,sizeof(dmfine_method),"PCTelescopeStateScatter");CHKERRQ(ierr); 212 ierr = PetscObjectQueryFunction((PetscObject)ctx->dm_fine,dmfine_method,&ctx->fp_dm_state_scatter);CHKERRQ(ierr); 213 } 214 215 if (ctx->fp_dm_state_scatter) { 216 ierr = PetscInfo(pc,"PCTelescope: Found composed method PCTelescopeStateScatter from parent DM\n");CHKERRQ(ierr); 217 } else { 218 ierr = PetscInfo(pc,"PCTelescope: Failed to find composed method PCTelescopeStateScatter from parent DM\n");CHKERRQ(ierr); 219 } 220 221 if (ctx->fp_dm_field_scatter) { 222 ierr = PetscInfo(pc,"PCTelescope: Found composed method PCTelescopeFieldScatter from parent DM\n");CHKERRQ(ierr); 223 } else { 224 ierr = PetscInfo(pc,"PCTelescope: Failed to find composed method PCTelescopeFieldScatter from parent DM\n");CHKERRQ(ierr); 225 SETERRQ(comm,PETSC_ERR_SUP,"No method to scatter fields between the parent DM and coarse DM was found. Must call PetscObjectComposeFunction() with the parent DM. Telescope setup cannot proceed"); 226 } 227 228 /*ierr = PCTelescopeSetUp_permutation_CoarseDM(pc,sred,ctx);CHKERRQ(ierr);*/ 229 ierr = PCTelescopeSetUp_scatters_CoarseDM(pc,sred,ctx);CHKERRQ(ierr); 230 PetscFunctionReturn(0); 231 } 232 233 PetscErrorCode PCApply_Telescope_CoarseDM(PC pc,Vec x,Vec y) 234 { 235 PC_Telescope sred = (PC_Telescope)pc->data; 236 PetscErrorCode ierr; 237 Vec xred,yred; 238 PC_Telescope_CoarseDMCtx *ctx; 239 240 PetscFunctionBegin; 241 ctx = (PC_Telescope_CoarseDMCtx*)sred->dm_ctx; 242 xred = sred->xred; 243 yred = sred->yred; 244 245 ierr = PetscCitationsRegister(citation,&cited);CHKERRQ(ierr); 246 247 if (ctx->fp_dm_state_scatter) { 248 ierr = ctx->fp_dm_state_scatter(ctx->dm_fine,SCATTER_FORWARD,ctx->dm_coarse);CHKERRQ(ierr); 249 } 250 251 ierr = ctx->fp_dm_field_scatter(ctx->dm_fine,x,SCATTER_FORWARD,ctx->dm_coarse,xred);CHKERRQ(ierr); 252 253 /* solve */ 254 if (PCTelescope_isActiveRank(sred)) { 255 ierr = KSPSolve(sred->ksp,xred,yred);CHKERRQ(ierr); 256 } 257 258 ierr = ctx->fp_dm_field_scatter(ctx->dm_fine,y,SCATTER_REVERSE,ctx->dm_coarse,yred);CHKERRQ(ierr); 259 PetscFunctionReturn(0); 260 } 261 262 PetscErrorCode PCTelescopeSubNullSpaceCreate_CoarseDM(PC pc,PC_Telescope sred,MatNullSpace nullspace,MatNullSpace *sub_nullspace) 263 { 264 PetscErrorCode ierr; 265 PetscBool has_const; 266 PetscInt k,n = 0; 267 const Vec *vecs; 268 Vec *sub_vecs = NULL; 269 MPI_Comm subcomm; 270 PC_Telescope_CoarseDMCtx *ctx; 271 272 PetscFunctionBegin; 273 ctx = (PC_Telescope_CoarseDMCtx*)sred->dm_ctx; 274 subcomm = sred->subcomm; 275 ierr = MatNullSpaceGetVecs(nullspace,&has_const,&n,&vecs);CHKERRQ(ierr); 276 277 if (PCTelescope_isActiveRank(sred)) { 278 /* create new vectors */ 279 if (n) { 280 ierr = VecDuplicateVecs(sred->xred,n,&sub_vecs);CHKERRQ(ierr); 281 } 282 } 283 284 /* copy entries */ 285 for (k=0; k<n; k++) { 286 ierr = ctx->fp_dm_field_scatter(ctx->dm_fine,vecs[k],SCATTER_FORWARD,ctx->dm_coarse,sub_vecs[k]);CHKERRQ(ierr); 287 } 288 289 if (PCTelescope_isActiveRank(sred)) { 290 /* create new (near) nullspace for redundant object */ 291 ierr = MatNullSpaceCreate(subcomm,has_const,n,sub_vecs,sub_nullspace);CHKERRQ(ierr); 292 ierr = VecDestroyVecs(n,&sub_vecs);CHKERRQ(ierr); 293 } 294 PetscFunctionReturn(0); 295 } 296 297 PetscErrorCode PCTelescopeMatNullSpaceCreate_CoarseDM(PC pc,PC_Telescope sred,Mat sub_mat) 298 { 299 PetscErrorCode ierr; 300 Mat B; 301 PC_Telescope_CoarseDMCtx *ctx; 302 303 PetscFunctionBegin; 304 ctx = (PC_Telescope_CoarseDMCtx*)sred->dm_ctx; 305 ierr = PCGetOperators(pc,NULL,&B);CHKERRQ(ierr); 306 { 307 MatNullSpace nullspace,sub_nullspace; 308 ierr = MatGetNullSpace(B,&nullspace);CHKERRQ(ierr); 309 if (nullspace) { 310 ierr = PetscInfo(pc,"PCTelescope: generating nullspace (CoarseDM)\n");CHKERRQ(ierr); 311 ierr = PCTelescopeSubNullSpaceCreate_CoarseDM(pc,sred,nullspace,&sub_nullspace);CHKERRQ(ierr); 312 313 /* attach any user nullspace removal methods and contexts */ 314 if (PCTelescope_isActiveRank(sred)) { 315 void *context = NULL; 316 if (nullspace->remove && !nullspace->rmctx){ 317 ierr = MatNullSpaceSetFunction(sub_nullspace,nullspace->remove,context);CHKERRQ(ierr); 318 } else if (nullspace->remove && nullspace->rmctx) { 319 char dmcoarse_method[PETSC_MAX_PATH_LEN]; 320 PetscErrorCode (*fp_get_coarsedm_context)(DM,void**) = NULL; 321 322 ierr = PetscSNPrintf(dmcoarse_method,sizeof(dmcoarse_method),"PCTelescopeGetCoarseDMNullSpaceUserContext");CHKERRQ(ierr); 323 ierr = PetscObjectQueryFunction((PetscObject)ctx->dm_coarse,dmcoarse_method,&fp_get_coarsedm_context);CHKERRQ(ierr); 324 if (!context) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Propagation of user null-space removal method with non-NULL context requires the coarse DM be composed with a function named \"%s\"",dmcoarse_method); 325 ierr = MatNullSpaceSetFunction(sub_nullspace,nullspace->remove,context);CHKERRQ(ierr); 326 } 327 } 328 329 if (PCTelescope_isActiveRank(sred)) { 330 ierr = MatSetNullSpace(sub_mat,sub_nullspace);CHKERRQ(ierr); 331 ierr = MatNullSpaceDestroy(&sub_nullspace);CHKERRQ(ierr); 332 } 333 } 334 } 335 { 336 MatNullSpace nearnullspace,sub_nearnullspace; 337 ierr = MatGetNearNullSpace(B,&nearnullspace);CHKERRQ(ierr); 338 if (nearnullspace) { 339 ierr = PetscInfo(pc,"PCTelescope: generating near nullspace (CoarseDM)\n");CHKERRQ(ierr); 340 ierr = PCTelescopeSubNullSpaceCreate_CoarseDM(pc,sred,nearnullspace,&sub_nearnullspace);CHKERRQ(ierr); 341 342 /* attach any user nullspace removal methods and contexts */ 343 if (PCTelescope_isActiveRank(sred)) { 344 void *context = NULL; 345 if (nearnullspace->remove && !nearnullspace->rmctx){ 346 ierr = MatNullSpaceSetFunction(sub_nearnullspace,nearnullspace->remove,context);CHKERRQ(ierr); 347 } else if (nearnullspace->remove && nearnullspace->rmctx) { 348 char dmcoarse_method[PETSC_MAX_PATH_LEN]; 349 PetscErrorCode (*fp_get_coarsedm_context)(DM,void**) = NULL; 350 351 ierr = PetscSNPrintf(dmcoarse_method,sizeof(dmcoarse_method),"PCTelescopeGetCoarseDMNearNullSpaceUserContext");CHKERRQ(ierr); 352 ierr = PetscObjectQueryFunction((PetscObject)ctx->dm_coarse,dmcoarse_method,&fp_get_coarsedm_context);CHKERRQ(ierr); 353 if (!context) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Propagation of user near null-space removal method with non-NULL context requires the coarse DM be composed with a function named \"%s\"",dmcoarse_method); 354 ierr = MatNullSpaceSetFunction(sub_nearnullspace,nearnullspace->remove,context);CHKERRQ(ierr); 355 } 356 } 357 358 if (PCTelescope_isActiveRank(sred)) { 359 ierr = MatSetNearNullSpace(sub_mat,sub_nearnullspace);CHKERRQ(ierr); 360 ierr = MatNullSpaceDestroy(&sub_nearnullspace);CHKERRQ(ierr); 361 } 362 } 363 } 364 PetscFunctionReturn(0); 365 } 366 367 PetscErrorCode PCReset_Telescope_CoarseDM(PC pc) 368 { 369 PetscErrorCode ierr; 370 PC_Telescope sred = (PC_Telescope)pc->data; 371 PC_Telescope_CoarseDMCtx *ctx; 372 373 PetscFunctionBegin; 374 ctx = (PC_Telescope_CoarseDMCtx*)sred->dm_ctx; 375 ctx->dm_fine = NULL; /* since I did not increment the ref counter we set these to NULL */ 376 ctx->dm_coarse = NULL; /* since I did not increment the ref counter we set these to NULL */ 377 ctx->permutation = NULL; /* this will be fetched from the dm so no need to call destroy */ 378 ierr = VecDestroy(&ctx->xp);CHKERRQ(ierr); 379 ctx->fp_dm_field_scatter = NULL; 380 ctx->fp_dm_state_scatter = NULL; 381 ctx->dmksp_context_determined = NULL; 382 ctx->dmksp_context_user = NULL; 383 PetscFunctionReturn(0); 384 } 385 386 PetscErrorCode PCApplyRichardson_Telescope_CoarseDM(PC pc,Vec x,Vec y,Vec w,PetscReal rtol,PetscReal abstol,PetscReal dtol,PetscInt its,PetscBool zeroguess,PetscInt *outits,PCRichardsonConvergedReason *reason) 387 { 388 PC_Telescope sred = (PC_Telescope)pc->data; 389 PetscErrorCode ierr; 390 Vec yred = NULL; 391 PetscBool default_init_guess_value = PETSC_FALSE; 392 PC_Telescope_CoarseDMCtx *ctx; 393 394 PetscFunctionBegin; 395 ctx = (PC_Telescope_CoarseDMCtx*)sred->dm_ctx; 396 yred = sred->yred; 397 398 if (its > 1) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"PCApplyRichardson_Telescope_CoarseDM only supports max_it = 1"); 399 *reason = (PCRichardsonConvergedReason)0; 400 401 if (!zeroguess) { 402 ierr = PetscInfo(pc,"PCTelescopeCoarseDM: Scattering y for non-zero-initial guess\n");CHKERRQ(ierr); 403 404 ierr = ctx->fp_dm_field_scatter(ctx->dm_fine,y,SCATTER_FORWARD,ctx->dm_coarse,yred);CHKERRQ(ierr); 405 } 406 407 if (PCTelescope_isActiveRank(sred)) { 408 ierr = KSPGetInitialGuessNonzero(sred->ksp,&default_init_guess_value);CHKERRQ(ierr); 409 if (!zeroguess) ierr = KSPSetInitialGuessNonzero(sred->ksp,PETSC_TRUE);CHKERRQ(ierr); 410 } 411 412 ierr = PCApply_Telescope_CoarseDM(pc,x,y);CHKERRQ(ierr); 413 414 if (PCTelescope_isActiveRank(sred)) { 415 ierr = KSPSetInitialGuessNonzero(sred->ksp,default_init_guess_value);CHKERRQ(ierr); 416 } 417 418 if (!*reason) *reason = PCRICHARDSON_CONVERGED_ITS; 419 *outits = 1; 420 PetscFunctionReturn(0); 421 } 422