mg2d: calculate the cfl from continuous diff coeffs

1 files changed, 19 insertions, 19 deletions

diff --git a/mg2d.c b/mg2d.c
index 01a6853..e0a83ed 100644
--- a/mg2d.c
+++ b/mg2d.c
@@ -778,21 +778,6 @@ static int mg_levels_init(MG2DContext *ctx)
     double diff0_max, diff2_max, tmp;
     int ret;
 
-    diff0_max = findmax(ctx->diff_coeffs[MG2D_DIFF_COEFF_00]->data, priv->root->solver->domain_size,
-                        ctx->diff_coeffs[MG2D_DIFF_COEFF_00]->stride);
-    diff2_max = findmax(ctx->diff_coeffs[MG2D_DIFF_COEFF_20]->data, priv->root->solver->domain_size,
-                        ctx->diff_coeffs[MG2D_DIFF_COEFF_20]->stride);
-    tmp = findmax(ctx->diff_coeffs[MG2D_DIFF_COEFF_02]->data, priv->root->solver->domain_size,
-                  ctx->diff_coeffs[MG2D_DIFF_COEFF_02]->stride);
-    diff2_max = MAX(diff2_max, tmp);
-
-    if (priv->dg->nb_components > 1) {
-        MPI_Allreduce(MPI_IN_PLACE, &diff0_max, 1,
-                      MPI_DOUBLE, MPI_MAX, priv->mpi_comm);
-        MPI_Allreduce(MPI_IN_PLACE, &diff2_max, 1,
-                      MPI_DOUBLE, MPI_MAX, priv->mpi_comm);
-    }
-
     cur  = priv->root;
     prev = NULL;
 
@@ -854,10 +839,6 @@ static int mg_levels_init(MG2DContext *ctx)
 
         cur->solver->fd_stencil = ctx->fd_stencil;
 
-        cur->solver->relax->relax_factor = ctx->cfl_factor;
-        cur->solver->relax->relax_multiplier = 1.0 / (diff2_max + cur->solver->step[0] * cur->solver->step[1] *
-                                                 diff0_max / 8.0);
-
         prev = cur;
         cur  = cur->child;
     }
@@ -902,8 +883,27 @@ static int mg_levels_init(MG2DContext *ctx)
         cur = cur->child;
     }
 
+    diff0_max = findmax(priv->diff_coeffs_tmp[MG2D_DIFF_COEFF_00]->data, priv->root->solver->domain_size,
+                        ctx->diff_coeffs[MG2D_DIFF_COEFF_00]->stride);
+    diff2_max = findmax(priv->diff_coeffs_tmp[MG2D_DIFF_COEFF_20]->data, priv->root->solver->domain_size,
+                        ctx->diff_coeffs[MG2D_DIFF_COEFF_20]->stride);
+    tmp = findmax(priv->diff_coeffs_tmp[MG2D_DIFF_COEFF_02]->data, priv->root->solver->domain_size,
+                  ctx->diff_coeffs[MG2D_DIFF_COEFF_02]->stride);
+    diff2_max = MAX(diff2_max, tmp);
+
+    if (priv->dg->nb_components > 1) {
+        MPI_Allreduce(MPI_IN_PLACE, &diff0_max, 1,
+                      MPI_DOUBLE, MPI_MAX, priv->mpi_comm);
+        MPI_Allreduce(MPI_IN_PLACE, &diff2_max, 1,
+                      MPI_DOUBLE, MPI_MAX, priv->mpi_comm);
+    }
+
     cur = priv->root;
     while (cur) {
+        cur->solver->relax->relax_factor = ctx->cfl_factor;
+        cur->solver->relax->relax_multiplier = 1.0 / (diff2_max + cur->solver->step[0] * cur->solver->step[1] *
+                                                 diff0_max / 8.0);
+
         if (cur->depth > 0) {
             ret = diff_coeffs_fixup(ctx, cur);
             if (ret < 0)