  We examine the marginal deformations of double-trace type in 3d
supersymmetric U(N) model with N complex free bosons and fermions. We compute
the anomalous dimensions of higher spin currents to the 1/N order but to all
orders in the deformation parameters by mainly applying the conformal
perturbation theory. The 3d field theory is supposed to be dual to 4d
supersymmetric Vasiliev theory, and the marginal deformations are argued to
correspond to modifying boundary conditions for bulk scalars and fermions. Thus
the modification should break higher spin gauge symmetry and generate the
masses of higher spin fields. We provide supports for the dual interpretation
by relating bulk computation in terms of Witten diagrams to boundary one in
conformal perturbation theory.
