ATLAS Detector Performance Challenges in Run 2

The talk should be prepared and given by the two speakers (ATLAS and CMS), and should present the challenges set by the Run2 conditions, i.e. larger in-time PU and larger out-of-time PU, for (i) tracking, vertexing, b-tagging, tau reconstruction; (ii) muon reconstruction; (iii) electron, photon & jet reconstruction. The presentation should also address how we face these aspects with the pre-LS2 detectors (readiness for the restart).