Silver-Mueller: Avoid Managed Memory (#2019)

Avoid relying on managed memory usage in Silver-Mueller boundary
conditions. Previously, we initialized the coefficients on the
host, copied them to device and then accidentially used the
device memory on the host again, as we calculated some constants.

This now keeps the initial host-memory around so we can use it
for host-only operations.

1 files changed, 6 insertions, 0 deletions

diff --git a/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceSolver.H b/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceSolver.H
index 92812d4e0..5346604d4 100644
--- a/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceSolver.H
+++ b/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceSolver.H
@@ -110,9 +110,15 @@ class FiniteDifferenceSolver
 #ifdef WARPX_DIM_RZ
         amrex::Real m_dr, m_rmin;
         int m_nmodes;
+        // host-only
+        amrex::Vector<amrex::Real> m_h_stencil_coefs_r, m_h_stencil_coefs_z;
+        // device copy after init
         amrex::Gpu::DeviceVector<amrex::Real> m_stencil_coefs_r;
         amrex::Gpu::DeviceVector<amrex::Real> m_stencil_coefs_z;
 #else
+        // host-only
+        amrex::Vector<amrex::Real> m_h_stencil_coefs_x, m_h_stencil_coefs_y, m_h_stencil_coefs_z;
+        // device copy after init
         amrex::Gpu::DeviceVector<amrex::Real> m_stencil_coefs_x;
         amrex::Gpu::DeviceVector<amrex::Real> m_stencil_coefs_y;
         amrex::Gpu::DeviceVector<amrex::Real> m_stencil_coefs_z;