The Performance and development of the ATLAS Inner Detector trigger at the LHC

A description of the algorithms and performance of the ATLAS Inner Detector trigger for LHC Run 1, and the prospects for a redesign of the tracking algorithms for Run 2 are presented. The Inner Detector trigger algorithms are vital for many trigger signatures at ATLAS. The performance of the algorithms for electron reconstruction is presented. The upgrade of the LHC to 13-14 TeV centre-of-mass energy will present a significant challenge for the trigger algorithms in terms of the execution time and in order to maintain the physics performance. To deal the expected high rates, the ATLAS High Level Trigger software is being restructured from two software levels used in LHC Run 1 to run as a single stage for Run 2. Expected future improvements in the timing and efficiencies of the Inner Detector triggers are briefly discusse