I have a kernel which, according to the Nsight analysis tool, could only ever achieve 50% occupancy. Anyone have any ideas why? Thanks.
__global__ void restriction(double *d_u, double *d_rhs, double *d_res ,int d_dimUcoarse, int d_dimUFine){
//Thread Indices
int x = blockIdx.x*blockDim.x+threadIdx.x+1;
int y = blockIdx.y*blockDim.y+threadIdx.y+1;
if(x<d_dimUcoarse&&y<d_dimUcoarse){
//Use half the defect
d_rhs[y*d_dimUcoarse+x]=d_res[2*y*d_dimUFine+2*x]/2.0;
d_u[y*d_dimUcoarse+x]=0;
}
}