I rent out the second bedroom in my primary residence. Should I list this as rental income, and should the interest/taxes for it go in rental expenses or the deductions?

I think this would be double the deductions. I know it asked me about "rental use percentage" and I put down 50% since I rented out 1 out of the two rooms. However, I looked at the final filing and it doesn't seem to halve the expenses for it. Am I doing this correctly?