xref: /petsc/src/ksp/pc/impls/mg/fmg.c (revision ae9b4142d2ca751b76c4cfd50549e9aa91b2b04f)
1 /*
2      Full multigrid using either additive or multiplicative V or W cycle
3 */
4 #include "src/ksp/pc/impls/mg/mgimpl.h"
5 
6 EXTERN PetscErrorCode PCMGMCycle_Private(PC_MG **,PetscTruth*);
7 
8 #undef __FUNCT__
9 #define __FUNCT__ "PCMGFCycle_Private"
10 PetscErrorCode PCMGFCycle_Private(PC_MG **mg)
11 {
12   PetscErrorCode ierr;
13   PetscInt       i,l = mg[0]->levels;
14 
15   PetscFunctionBegin;
16   /* restrict the RHS through all levels to coarsest. */
17   for (i=l-1; i>0; i--){
18     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventBegin(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
19     ierr = MatRestrict(mg[i]->restrct,mg[i]->b,mg[i-1]->b);CHKERRQ(ierr);
20     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventEnd(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
21   }
22 
23   /* work our way up through the levels */
24   ierr = VecSet(mg[0]->x,0.0);CHKERRQ(ierr);
25   for (i=0; i<l-1; i++) {
26     ierr = PCMGMCycle_Private(&mg[i],PETSC_NULL);CHKERRQ(ierr);
27     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventBegin(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
28     ierr = MatInterpolate(mg[i+1]->interpolate,mg[i]->x,mg[i+1]->x);CHKERRQ(ierr);
29     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventEnd(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
30   }
31   ierr = PCMGMCycle_Private(&mg[l-1],PETSC_NULL);CHKERRQ(ierr);
32   PetscFunctionReturn(0);
33 }
34 
35 #undef __FUNCT__
36 #define __FUNCT__ "PCMGKCycle_Private"
37 PetscErrorCode PCMGKCycle_Private(PC_MG **mg)
38 {
39   PetscErrorCode ierr;
40   PetscInt       i,l = mg[0]->levels;
41 
42   PetscFunctionBegin;
43   /* restrict the RHS through all levels to coarsest. */
44   for (i=l-1; i>0; i--){
45     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventBegin(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
46     ierr = MatRestrict(mg[i]->restrct,mg[i]->b,mg[i-1]->b);CHKERRQ(ierr);
47     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventEnd(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
48   }
49 
50   /* work our way up through the levels */
51   ierr = VecSet(mg[0]->x,0.0);CHKERRQ(ierr);
52   for (i=0; i<l-1; i++) {
53     if (mg[i]->eventsmoothsolve) {ierr = PetscLogEventBegin(mg[i]->eventsmoothsolve,0,0,0,0);CHKERRQ(ierr);}
54     ierr = KSPSolve(mg[i]->smoothd,mg[i]->b,mg[i]->x);CHKERRQ(ierr);
55     if (mg[i]->eventsmoothsolve) {ierr = PetscLogEventEnd(mg[i]->eventsmoothsolve,0,0,0,0);CHKERRQ(ierr);}
56     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventBegin(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
57     ierr = MatInterpolate(mg[i+1]->interpolate,mg[i]->x,mg[i+1]->x);CHKERRQ(ierr);
58     if (mg[i]->eventinterprestrict) {ierr = PetscLogEventEnd(mg[i]->eventinterprestrict,0,0,0,0);CHKERRQ(ierr);}
59   }
60   if (mg[l-1]->eventsmoothsolve) {ierr = PetscLogEventBegin(mg[l-1]->eventsmoothsolve,0,0,0,0);CHKERRQ(ierr);}
61   ierr = KSPSolve(mg[l-1]->smoothd,mg[l-1]->b,mg[l-1]->x);CHKERRQ(ierr);
62   if (mg[l-1]->eventsmoothsolve) {ierr = PetscLogEventEnd(mg[l-1]->eventsmoothsolve,0,0,0,0);CHKERRQ(ierr);}
63 
64   PetscFunctionReturn(0);
65 }
66 
67 
68