Measurements of double helicity asymmetries in inclusive hadron production in polarized p + p collisions are sensitive to helicity-dependent parton distribution functions, in particular to the gluon helicity distribution, Δg. This study focuses on the extraction of the double helicity asymmetry in η production (p+p → η+X), the η cross section and the η/π⁰ cross section ratio. The cross section and ratio measurements provide essential input for the extraction of fragmentation functions that are needed to access the helicity-dependent parton distribution functions.