ATLAS inner tracking detectors: Run 1 performance and developments for Run 2

The measurement of charged-particle trajectories with the inner tracking detectors of the ATLAS experiment at the LHC is a key input for higher-level object reconstruction, ranging from leptons to the identification of heavy-flavor jets. The information provided by the inner tracking systems has also been proven to be very powerful for disentangling the effects of several interactions occurring in the same bunch crossing. In this contribution, the performance during the Run 1 data-taking period and preparation for the next run in 2015 is reviewed. In particular, it is shown how the passive material inside the inner tracking acceptance has been further studied in order to reduce the systematic errors on the tracking efficiency, with benefits for physics measurements. In addition, the developments in disentangling close-by tracks which naturally occur in the decay of very high-$p_\mathrm{T}$ objects (e.g. tau leptons) or jets are presented. The ongoing upgrade of the ATLAS detector includes an additional silicon layer (IBL) in the inner tracking system; the preparation for the integration of the new hardware and its expected performance is reviewed as well. Finally a summary of recent developments of the tracking software aiming for speed and disk-space optimizations is presented.