Simulation-based temporal debugging of Linux

We present a temporal debugger, capable of examining tempor al behaviour of operating systems. The debugger is based on a simulator modelling an entire workstation at th e instruction level. Unlike traditional debuggers, which need to interfere with program execution, a simulation-bas ed debugger can operate without disturbing time flow of the simulated system. This allows non-intrusive and reproduci ble debugging of general-purpose operating systems, such as Linux. We demonstrate the utility of the temporal debugger by analy sing two time sensitive parts of Linux, scheduling and interrupt handling. We show how our tool allows a user to iden tify and isolate temporally unsatisfactory behaviour, and examine short sequences in detail.