  This contribution reports on the first measurement of the longitudinal
double-spin asymmetry $A_{LL}$ for the inclusive production of jets in
polarized proton-proton collisions at $\sqrt{s}=200 \mathrm{GeV}$. The data
were collected with STAR at RHIC in the years 2003 and 2004, and correspond to
a sampled integrated luminosity of $0.3 \mathrm{pb}^{-1}$ with beam
polarizations up to 45%. The results on $A_{LL}$ cover jet transverse momenta
$5 < p_{T} < 17 \mathrm{GeV/c}$ and agree with perturbative QCD evaluations
based on deep-inelastic scattering parametrizations for the gluon polarization
in the proton. The results disfavor large positive gluon polarization in the
polarized proton.
