xref: /petsc/src/ksp/pc/impls/mg/smg.c (revision bebe2cf65d55febe21a5af8db2bd2e168caaa2e7)
1 
2 /*
3      Additive Multigrid V Cycle routine
4 */
5 #include <petsc/private/pcmgimpl.h>
6 
7 #undef __FUNCT__
8 #define __FUNCT__ "PCMGACycle_Private"
9 PetscErrorCode PCMGACycle_Private(PC pc,PC_MG_Levels **mglevels)
10 {
11   PetscErrorCode ierr;
12   PetscInt       i,l = mglevels[0]->levels;
13 
14   PetscFunctionBegin;
15   /* compute RHS on each level */
16   for (i=l-1; i>0; i--) {
17     if (mglevels[i]->eventinterprestrict) {ierr = PetscLogEventBegin(mglevels[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
18     ierr = MatRestrict(mglevels[i]->restrct,mglevels[i]->b,mglevels[i-1]->b);CHKERRQ(ierr);
19     if (mglevels[i]->eventinterprestrict) {ierr = PetscLogEventEnd(mglevels[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
20   }
21   /* solve separately on each level */
22   for (i=0; i<l; i++) {
23     ierr = VecSet(mglevels[i]->x,0.0);CHKERRQ(ierr);
24     if (mglevels[i]->eventsmoothsolve) {ierr = PetscLogEventBegin(mglevels[i]->eventsmoothsolve,0,0,0,0);CHKERRQ(ierr);}
25     ierr = KSPSolve(mglevels[i]->smoothd,mglevels[i]->b,mglevels[i]->x);CHKERRQ(ierr);
26     if (mglevels[i]->eventsmoothsolve) {ierr = PetscLogEventEnd(mglevels[i]->eventsmoothsolve,0,0,0,0);CHKERRQ(ierr);}
27   }
28   for (i=1; i<l; i++) {
29     if (mglevels[i]->eventinterprestrict) {ierr = PetscLogEventBegin(mglevels[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
30     ierr = MatInterpolateAdd(mglevels[i]->interpolate,mglevels[i-1]->x,mglevels[i]->x,mglevels[i]->x);CHKERRQ(ierr);
31     if (mglevels[i]->eventinterprestrict) {ierr = PetscLogEventEnd(mglevels[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
32   }
33   PetscFunctionReturn(0);
34 }
35