ATLAS LAr Calorimeter Performance in LHC Run-2

Liquid-argon (LAr) sampling calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region $\eta<3.2$, and for hadronic and forward calorimetry in the region from $\eta=1.5$ to $\eta=4.9$. In the first LHC run a total luminosity of $27\,\mathrm{fb}^{-1}$ has been collected at centre-of-mass energies of $7-8\,\mathrm{TeV}$. After detector consolidation during a long shutdown, Run-2 started in 2015 and $86.4\,\mathrm{fb}^{-1}$ of data at a centre-of-mass energy of $13\,\mathrm{TeV}$ have been recorded. In order to realize the level-1 acceptance rate of $100\,\mathrm{kHz}$ in Run-2 data taking, the number of readout samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibrated and highly granular LAr calorimeter reached its design values both in energy measurement as well as in direction resolution. This contribution will give an overview of the detector operation, hardware improvements, changes in the monitoring and data quality procedures, to cope with increased pileup, as well as the achieved performance, including the calibration and stability of the electromagnetic scale, noise level, response uniformity and time resolution.