1. A computer-implemented method comprising: receiving an interrupt at a device driver executing on a processor; in response to receiving the interrupt, storing, by the device driver, sampled context information that corresponds to a native process that is executing on the processor; in response to storing the sampled context information, using the device driver to notify a sampling thread; in response to being notified, using the sampling thread to identify one or more returned call stack nodes; correlating, using the sampling thread, the returned call stack nodes with the sampled context information, the correlating further comprising: identifying, based upon the sampled context information, one or more native function leaf nodes that correspond to the native process; and integrating the native function leaf nodes with the returned call stack nodes, the integrating resulting in a unified output tree; and storing the unified output tree.