The presentation will cover recent developments in hardware trace support on Arm linux platforms to include:- 1) AutoFDO - Optimising production code using trace sampling as feedback. A description of the methods and the developments needed to use this tool. 2) Trace capture techniques using CTI and ETM - Using CTIs to halt trace on software events. Using ETMs to inject events into the trace streams. 3) CoreSight Base System Architecture - an introduction to Arm’s effort to introduce a standardised trace platform, to allow better tool compatibility across devices.