Operating System (OS) noise is a well-known phenomenon in which OS activities interfere with the execution of large-scale parallel applications. Due to OS noise, feature-rich software environments such as Linux can seriously affect scalability. Kernel tracing can be used to identify OS noise sources, but until recently it required substantial OS modifications. This paper presents Jitter-Trace, a low-overhead tool that identifies and quantifies jitter sources. Jitter-Trace calculates the jitter generated by each OS activity, providing a complete set of task profiles and histograms of OS noise. This data is essential to implement OS noise mitigation strategies and reduce its impact on scalability. Jitter-Trace leverages the tracing and profiling capabilities of Linux Perf, which is widely available in current Linux distributions. Perf is tightly integrated in the Linux kernel and features a lightweight implementation.