https://peertube.watch/videos/watch/cb70497a-7144-48fc-bc55-33d8c0eb01f2 Introducing Ftrace and using it for Linux realtime application Ftrace (Function Tracer) is a very famous tracing/debugging tool. It is built directly into the Linux kernel and most of standard distributions already have various configurations of Ftrace enabled in their most recent releases. One of the benefits that Ftrace brings to Linux is the ability to see what is happening inside the kernel with a large number of 'tracers' (function or events) . kernel function calling tree and timestamps, kernel events (such as processus wakeup or switch), As such, this makes finding problem areas or simply tracking down that strange bug more manageable. Ftrace's ability to show the events that lead up to severe problem gives a better chance of finding exactly what caused it and can help the developer a lot. API to talk with Ftrace is located in a Debugfs file system. typically mounted at /sys/kernel/debug. You can also use 'trace-cmd' utility for easier access. After a brief history and introduction about tracing tools (SystemTap, eBPF, LTT-ng, ...) we will (briefly) talk about Ftrace internals and describe main features : installing it on embedded distribution such as Buildroot or Yocto (ARM platform), tracing kernel functions (function, function_graph), kernel messages (trace_printk), markers (trace_marker), events, After describing a simple use-case for a kernel driver we will focus on events and use trace-cmd on "realtime" application running on standard Linux then PREEMPT_RT (ARM). We will compare performances of a POSIX based periodic task using SCHEDFIFO or SCHEDOTHER on both kernel and finally generate graphs with GNU-plot. Speaker: Pierre Ficheux, Track: Debugging tools, Room: AW1.121, When: Saturday 3 February 2018, 14:25–14:50 (Brussels time), Schedule: FOSDEM 2018 event page, Slides & links https://www.kernel.org/doc/Documentation/trace/ftrace.txt, https://elinux.org/Ftrace, Licence: Creative Commons Attribution 2.0 Belgium (CC BY 2.0 BE) (as stated in the FOSDEM video archive). Attribution: “Debugging realtime application with Ftrace” by Pierre Ficheux, FOSDEM 2018. Original recording: 2018/AW1.121/debugging_tools_ftrace.webm from the FOSDEM video archive. This channel is an unofficial mirror; FOSDEM is a free and non-commercial event organised by the community for the community. Mon, 12 Oct 2026 03:47:30 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://peertube.watch https://peertube.watch/lazy-static/avatars/3b284627-b75f-409e-ac2e-10f4c2946f43.png https://peertube.watch/videos/watch/cb70497a-7144-48fc-bc55-33d8c0eb01f2 All rights reserved, unless otherwise specified in the terms specified at https://peertube.watch/about and potential licenses granted by each content's rightholder.