Linux Plumbers Conference 2026

Session

Tracing MC

6 Oct 2026, 10:00

Description

Description:
Visibility into the Linux kernel has always been critical for debugging and validating the execution of the code. The never ending challenge is to be able to trace the code without causing extra overhead, as tracing is most useful in a production environment.

Possible topics for this year include:

• Updating the deferred stack tracer for sframes.
• A light weight lock stat tracer
• More read1ng of user space from syscall tracepoints
• Additions to the persistent ring buffer
• Adding error injection via trace points and kprobes
• Doing more with synthetic events
• Rewriting the histogram/trigger/synthetic event code

And much more

What has been done before
Here's the enhancements that were added to Linux tracing that were derived from the previous Tracing MC session:

• libside has been released for better user space tracepoint hooking
• Faultable system call tracepoints
• We have a new Runtime Verification maintainer!

Key Attendees:

• Steven Rostedt
• Masami Hiramatsu
• Mathieu Desnoyers
• Ian Rogers
• Gabriele Monaco
• Namhyung Kim
• Arnaldo Carvalho de Melo
• Tomas Glozar
• Peter Zijlstra
• Jens Remus

237. Sharing trace infrastructure between in-tree and OOT tracers

Mathieu Desnoyers (EfficiOS Inc.)

06/10/2026, 12:00

The current situation regarding LTTng vs upstream Linux:

1) There are maintainers who push for everything to be in tree
2) There are maintainers who are proponents for no-GPL-export when there are no in-tree users
3) Most of the tracer common facilities are used by tracers which do not compile as modules (only builtin)
4) Linus Torvalds stated that LTTng will stay out of tree

As a...

89. DEPT (DEPendency Tracker): A Path to Mainline and Solving the False Positive Challenge

Byungchul Park

DEPT (DEPendency Tracker) is a runtime dependency tracking framework
that detects potential deadlocks by tracking wait/event relationships
rather than lock acquisition order. Unlike lockdep, which is limited to
typical locking primitives, DEPT can detect deadlocks involving general
synchronization mechanisms such as folio locks, completions, DMA fences,
and other wait/event-based...

40. Bridging perf and ftrace: Converting perf.data Tracepoint Events to trace.dat for KernelShark Visualization

Madhavan Srinivasan, Steven Rostedt, Tanushree Shah

The Linux kernel tracing ecosystem comprises two complementary toolchains: perf for statistical profiling and performance analysis, and ftrace/trace-cmd for event timeline visualization. While perf captures comprehensive performance data with minimal overhead, understanding temporal relationships and event sequences remains challenging through its native interfaces. In contrast, KernelShark...

303. Developing Next Generation Perf Tools With Python

Ms Alice Rogers, Ian Rogers (Google)

Traditionally, the Linux perf tool has relied on a text user interface (TUI) based on libslang and embedded Python/Perl interpreters for scripting support. However, developing robust user interfaces in C is tedious and error-prone, and using perf itself as the interpreter integrates poorly with broader programming language ecosystems.

In this talk, we will describe how we refactored perf...

101. Probe events with typecast using BTF

Mr Masami Hiramatsu (Google)

BTF fetcharg has been introduced since v6.5 for fprobe and kprobe events for fetching function parameters by name, and now we intrdouced typecast feature for BTF. This typecast feature is not only casting type, but also, the series supports nested typecasts, container_of(), this_cpu_ptr(), and "current" task structure access. With these features, we can access more context local data from...

110. Lightweight Preempt and IRQ Tracepoints for Production RT Kernels

Mr Wander Costa (Red Hat)

Debugging latency issues in production RT kernels often requires
understanding where and why preemption and interrupts are being
disabled. Today, enabling the preempt_disable/enable and
irq_disable/enable tracepoints requires pulling in heavyweight
infrastructure — either the preemptoff/irqsoff latency tracers or the
full lockdep IRQ tracking — that carries too much overhead...

425. Handling stack traces in tracing

Steven Rostedt

Stack tracing of events can be very useful, for both kernel stack tracing as well as user space stack tracing. Stack traces can fill the buffer quickly with many duplicate stacks. Having a way to consolidate them would make it possible to store even more data. There's been [efforts][1] to do this but how to implement it and the interface is still an ongoing subject.

On top of that, tracing...

302. Build ID + offset sampling in perf events

Ian Rogers (Google)

Performance event sampling traditionally captures virtual addresses, resolving them to file offsets and symbols post-facto via mmap metadata. Conversely, BPF enables a direct approach: recording the file's build ID and offset within the sample itself. While virtual addresses are smaller inline, the required mmap event stream may lead to much larger raw data files.

In this talk, we examine...