sched_ext is a Linux kernel feature which enables implementing host-wide, safe kernel thread schedulers in BPF, and dynamically loading them at runtime. sched_ext enables safe and rapid iterations of scheduler implementations, thus radically widening the scope of scheduling strategies that can be experimented with and deployed, even in massive and complex production environments.

sched_ext was first sent to the upstream list as an RFC patch set back in November 2022. Since then, the project has evolved a great deal, both technically, as well as in the significant growth of the community of sched_ext users and contributors.

This MC is the space for the community to discuss the developments of sched_ext, its impact on the community, and to outline future strategies aimed at integrating this feature into the Linux kernel and mainstream Linux distributions.

Ideas of topics to be discussed include (but are not limited to):

• Challenges and plans to facilitate the upstream merge of sched_ext
• User-space scheduling (offload part / all of the scheduling from kernel to user-space)
• Scheduling for gaming and latency-sensitive workloads
• Scheduling & cpufreq integration
• Distro support

While we anticipate having a schedule with existing talk proposals at the MC, we invite you to submit proposals for any topic(s) you’d like to discuss. Time permitting, we are happy to readjust the schedule for additional topics that are of relevance to the sched_ext community.

Submissions are made via LPC submission system, selecting the track Sched-Ext: The BPF extensible scheduler class.

We will consider the submissions until July 12th.

The Linux kernel has grown in complexity over the years. Complete understanding of how it works via code inspection has become virtually impossible. Today, tracing is used to follow the kernel as it performs its complex tasks. Tracing is used today for much more than simply debugging. Its framework has become the way for other parts of the Linux kernel to enhance and even make possible new features. Live kernel patching is based on the infrastructure of function tracing, as well as BPF. It is now even possible to model the behavior and correctness of the system via runtime verification which attaches to trace points. There is still much more that is happening in this space, and this microconference will be the forum to explore current and new ideas.

This year, focus will also be on perf events:

Perf events are a mechanism for presenting performance counters and Linux software events to users. There are kernel and userland components to perf events. The kernel supplies the APIs and the perf tooling presents the data to users.

Possible ideas for topics for this year’s conference:

• Feedback about the tracing/perf subsystems overall (e.g. how can people help the maintainers).
• Reboot persistent in-memory tracing buffers, this would make ftrace a very powerful debugging and performance analysis tool for kexec and could also be used for post crash debugging.
• – Handling exposing enum names dynamically to user space to improve symbolic printing.
• Userspace instrumentation (libside), including discussion of its impacts on the User events ABI.
• Collect state dump events from kernel drivers (e.g. dump wifi interfaces configuration at a given point in time through trace buffers).
• Current work implementing performance monitoring in the kernel
• User land profiling and analysis tools using the perf event API
• Improving the kernel perf event and PMU APIs
• Interaction between perf events and subsystems like cgroups, kvm, drm, bpf, etc.
• Improving the perf tool and its interfaces in particular w.r.t. to scalability of the tool
• Implementation of new perf features and tools using eBPF, like the ones in tools/perf/util/bpf_skel/
• Further use of type information to augment the perf tools
• Novel uses of perf events for debugging and correctness
• New challenges in performance monitoring for the Linux kernel
• Regression testing/CI integration for the perf kernel infrastructure and tools
• Improving documentation
• Security aspects of using tracing/perf tools

The submission deadline has been updated to July 12th.

Come and join us in the discussion, we hope to see you there!

Please follow the suggestions from this BLOG post when submitting a CFP for this track.

Submissions are made via LPC submission system, selecting Track “Tracing / Perf events MC”