Open Source Summit Europe 2025: Full Schedule

25-27, August 2025
Amsterdam, Netherlands
View More Details & Registration
Note: The schedule is subject to change.

The Sched app allows you to build your schedule but is not a substitute for your event registration. You must be registered for Open Source Summit Europe 2025 to participate in the sessions. If you have not registered but would like to join us, please go to the event registration page to purchase a registration.

This schedule is automatically displayed in Central European Summer Time, CEST (UTC +2). To see the schedule in your preferred timezone, please select from the drop-down menu to the right.

IMPORTANT NOTE: Timing of sessions and room locations are subject to change.

arrow_back View All Dates

11:00 CEST

Three Decades in Kernelland - Jonathan Corbet, LWN.net

Tuesday August 26, 2025 11:00 - 11:40 CEST

G102-103

The Linux kernel project has been going for well over 30 years. From its beginnings on floppy diskettes and beige boxes through to its current home in pockets and unseen data centers, the kernel project has been a constant exercise in rapid development and adaptation. I have been present for almost all of the kernel project's history as an observer, contributor, maintainer, and more; all that experience will be boiled down into a fast-moving tour of how the kernel got to where it is, what makes it successful, and what may be coming next.

Speakers

Jonathan Corbet

Executive editor, LWN.net

Jonathan Corbet is the kernel documentation maintainer, co-founder of

Tuesday August 26, 2025 11:00 - 11:40 CEST
G102-103

Linux

Audience Experience Level Intermediate

11:55 CEST

The Power of the Device Mapper - From Dm-cache To Dm-zoned - Werner Fischer, Thomas-Krenn.AG

Tuesday August 26, 2025 11:55 - 12:35 CEST

G102-103

The device mapper has been part of the Linux kernel since kernel version 2.6. It allows the creation of virtual block devices by mapping their address space to other block devices or special functions. In this way, it can map physical block devices such as hard disks or SSDs to higher-level virtual block devices. It is the basis for the Logical Volume Manager (LVM), Linux software RAIDs and dm-crypt encryption, and provides additional features such as file system snapshots.

However, the use of Device Mapper targets is not limited to that. Many other targets offer often unknown features. Most of these are intended for production use. However, there are also some targets designed specifically for debugging.

In this talk, Werner gives a full overview of all Device Mapper targets.

For production use these are: dm-cachd, dm-clone, dm-crypt, dm-ebs, dm-era, dm-integrity, dm-linear, dm-mirror, dm-raid, dm-stripe, dm-switch, dm-thin, dm-unstripe, dm-verity, dm-vdo, dm-writecache and dm-zoned.

For debugging: dm-delay, dm-dust, dm-flakey and dm-zero.

He also briefly shows drbd, md (RAID) and bcache, which, like device mapper targets, can work as devices "on top" of normal block devices.

Speakers

Werner Fischer

Product Manager, Thomas-Krenn.AG

Werner studied computer and media security in Hagenberg and then worked at IBM for two years, where he wrote two Redbooks with colleagues. He has been working in the Linux area at Thomas-Krenn.AG since 2005. His previous roles include HA clusters, devops, 3rd level support, security... Read More →

Tuesday August 26, 2025 11:55 - 12:35 CEST
G102-103

Linux

Audience Experience Level Beginner

11:55 CEST

Understanding Data Races in the Linux Kernel - Abhirup Vijay Gunakar, Arizona State University

Tuesday August 26, 2025 11:55 - 12:35 CEST

G104

Data races in the Linux kernel can lead to unpredictable behavior, silent data corruption, and severe security vulnerabilities. In this session, we’ll explore how concurrency works in the kernel, explain the root causes of kernel data races, and illustrate how they can silently destabilize entire systems.

We’ll then dive into the Kernel Concurrency Sanitizer (KCSAN), a specialized tool that helps developers detect data races in kernel code. You’ll learn how KCSAN differs from user-space tools like ThreadSanitizer (TSan), understand its dynamic instrumentation approach, and see how to read typical race reports. We’ll also discuss best practices for preventing kernel data races: consistent use of spinlocks, mutexes, atomics, and lock ordering conventions.

By the end of this talk, you’ll grasp the core challenges of concurrency in the Linux kernel, know how to spot and diagnose data races using KCSAN, and walk away with proven techniques for keeping kernel code race-free and reliable.

Speakers

Abhirup Vijay Gunakar

Systems Security Researcher, Arizona State University

Abhirup Vijay Gunakar is a Systems Security Researcher at Arizona State University, focused on kernel-level concurrency, data-race detection, and serverless architectures. He has explored advanced debugging strategies to enhance the reliability of multithreaded systems including the... Read More →

Tuesday August 26, 2025 11:55 - 12:35 CEST
G104

Linux

Audience Experience Level Intermediate

14:10 CEST

Extending Container Performance Isolation: Regulating Memory Bandwidth & Cache in the Kernel - Jonathan Perry, Unvariance

Tuesday August 26, 2025 14:10 - 14:50 CEST

G102-103

While containers provide isolation for CPU cycles and memory capacity, they offer limited protection against performance interference through shared CPU caches and memory bandwidth. Such contention was shown to increase application response times by 4-13x. The Linux resctrl infrastructure provides monitoring and control mechanisms, but has limitations for controlling real-world applications.

For example, child processes do not inherit their parent's resctrl groups, leaving any application that forks improperly monitored and controlled. Additionally, the current filesystem-based interface makes it difficult to build a controller that can monitor and adjust quickly enough to keep up with frequently changing application memory behavior.

This talk introduces the memory interference problem and presents new kernel mechanisms to address these limitations. A new collector enables effective control by capturing per-container measurements of cache and memory bandwidth usage at millisecond frequencies. We'll cover how the solution combines Intel RDT, AMD QoS, high-resolution timers, perf counters, and cgroups to achieve this. We'll discuss future work and opportunities for collaboration.

Speakers

Jonathan Perry

Founder, Unvariance

I am a maintainer of the OpenTelemetry eBPF network collector, and working on developing tools to detect and mitigate noisy neighbors. I got my PhD in noisy neighbor mitigation (focusing on networking) from MIT, then founded an eBPF-based network observability company, Flowmill, which... Read More →

Tuesday August 26, 2025 14:10 - 14:50 CEST
G102-103

Linux

Audience Experience Level Beginner

14:10 CEST

Hybrid THP Mechanism. Selective Use of Huge Pages by Hot Applications - Asier Gutierrez, Huawei

Tuesday August 26, 2025 14:10 - 14:50 CEST

G104

Currently, THP policies are used globally, for the entire system. This leads to memory fragmentation and memory waste. Main memory has increased a lot faster than TLB entries, and it will continue to do so. Given the limited TLB cache entries, this becomes a serious bottleneck for real world applications. Huge pages are supposed to resolve this issue, since the a single entry in the TLB can map a big chunk of memory. However, this eventually leads to memory fragmentation and eventually the system runs out of usable memory. Hence, most sysadmins and user space application suggest to disable huge pages

We introduce a hybrid page mechanism where hot applications can use huge pages transparently, while avoiding the entire system to use huge pages.

During the talk, we will show how we managed to decrease the huge page consumption as well as benchmarks on real applications.

Speakers

Asier Gutierrez

Staff software engineer, Huawei

I am a seasoned software engineer, with a wide background in product and system programming. I have worked for big companies like Intel, IBM and Yandex, as well as small startups. I spoke at the Open Source Summit Europe in 2023 where I showed how IMA namespaces can be used to achieve... Read More →

Tuesday August 26, 2025 14:10 - 14:50 CEST
G104

Linux

Audience Experience Level Any

15:05 CEST

More Effective Approach To Detecting Potential Deadlocks, DEPT(DEPendency Tracker) - Byungchul Park, SK hynix

Tuesday August 26, 2025 15:05 - 15:45 CEST

G104

Lockdep is a tool in the Linux kernel designed to detect potential deadlocks by tracking the order in which locks are acquired. However, deadlocks can occur not only due to incorrect lock acquisition order, but also from waits that cannot be resolved. For more effective deadlock detection, it is crucial to track the waits and events themselves, rather than focusing on lock acquisition order. This is where DEPT (DEPendency Tracker) comes in. DEPT accurately identifies conditions that can lead to deadlocks by tracking waits and events. Let me introduce DEPT and explain how it works.

[limitation of lockdep]
https://lore.kernel.org/lkml/6383cde5-cf4b-facf-6e07-1378a485657d@I-love.SAKURA.ne.jp/
https://lore.kernel.org/all/20250513175633.85f4e19f4232a68ab04c8e41@linux-foundation.org/

[dept playing role in practice]
https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.park@lge.com/
https://lore.kernel.org/all/b6e00e77-4a8c-4e05-ab79-266bf05fcc2d@igalia.com/

[dept series]
https://lore.kernel.org/all/20250519091826.19752-1-byungchul@sk.com/

Speakers

Byungchul Park

Linux kernel developer, SK hynix

Linux kernel developer and mainline Linux kernel contributor focusing on core subsystems especially task scheduler, synchronization mechanisms, and memory management.

Tuesday August 26, 2025 15:05 - 15:45 CEST
G104

Linux

Audience Experience Level Beginner

15:05 CEST

NGNFS: Designing a High Performance File System - Ric Wheeler, Versity Software

Tuesday August 26, 2025 15:05 - 15:45 CEST

G102-103

Modern NVME storage devices and networks present an opportunity to rethink how distributed file systems are built. NGNFS is designed to support high performance for the largest collections of data.

This talk decribes the key uses for this kind of file system, the high level design of NGNFS and gives an update on the progress of the project.

Speakers

Ric Wheeler

VP of Engineering, Versity Software

Ric works at Versity Software as the VP of Engineering. In the past, Ric has worked at IonQ on quantum computers, Meta's Reality Lab on devices and lead Red Hat's file & storage teams.

Tuesday August 26, 2025 15:05 - 15:45 CEST
G102-103

Linux

Audience Experience Level Intermediate

16:20 CEST

Lightning Talk: Integrating and Extending Battery Health Preservation Support in Linux - Jelle van der Waa, Red Hat

Tuesday August 26, 2025 16:20 - 16:30 CEST

G102-103

Since GNOME 48, users can now on a limited set of hardware configure battery health preservation by setting charge limits. This works by setting a start and stop charge limit to prevent trickle charging or always charging the last X% of the battery preventing unneeded wear when they are mostly used plugged in to external power.

In this talk the existing sysfs API is explained, its limitations and the implementation of a new API (charge_types) to support specific Dell laptops and move other laptops over from non-standard sysfs API's to a new API which applications like UPower will use to offer battery health preservation to more models.

Speakers

Jelle van der Waa

Software Engineer, Red Hat

Jelle started contributing to Open Source by helping package software in Arch Linux, and since then has been involved in various software projects. By day works on Cockpit for Red Hat, as side project hacks on the kernel / user space, reproducible builds and Arch Linux as Develop... Read More →

Tuesday August 26, 2025 16:20 - 16:30 CEST
G102-103

Linux

Audience Experience Level Intermediate

16:20 CEST

Data Placement in Linux: Evolving Block and File I/O - Kanchan Joshi, Samsung Semiconductor

Tuesday August 26, 2025 16:20 - 17:00 CEST

G104

As technologies evolve, so must Linux. Flexible Data Placement (FDP) is a new storage capability that gives the host more influence over the physical data layout—crucial for improving performance, usable space, and overall energy efficiency.

While initial Linux support was possible through an io_uring-driven passthrough interface, many real-world deployments require block and file path support, as well as collaboration across the I/O stack.

This talk will present the current state in Linux, dive into key design decisions, and walk through how both block and file I/O paths are being adapted to better take advantage of data placement. Expect discussion around the use of per-file and extended per-I/O interfaces that involve io_uring, filesystems, the block layer, and the NVMe driver.

Whether you are developing filesystems, optimizing performance tools, or are simply curious about how Linux keeps up with evolving hardware, this presentation offers a glimpse into the next stage of I/O evolution with deeper software–hardware coordination.

Speakers

Kanchan Joshi

Kanchan Joshi, Samsung Semiconductor

Kanchan is a upstream kernel developer, and his current work revolves around adding advancements in the Linux I/O stack. He has presented at OSS, SDC, LPC, and regularly presents at LSF/MM and upstream forums. He has engaged in system-software development across operating systems... Read More →

Tuesday August 26, 2025 16:20 - 17:00 CEST
G104

Linux

Audience Experience Level Intermediate

16:35 CEST

Interrupts: The Hidden World of Linux Performance - Shaghayegh Tavakoli, IONOS

Tuesday August 26, 2025 16:35 - 16:45 CEST

G102-103

In this 10-minute talk, I will dive into the often-overlooked world of Linux kernel performance, focusing on Hard IRQs and Soft IRQs. These two types of interrupt handling play a critical role in system efficiency and responsiveness, yet many developers are unaware of their inner workings. I will explore the fundamental differences between Hardirqs and Softirqs, their impact on CPU scheduling, and how they influence real-time performance. By the end of the session, attendees will have a clearer understanding of how these mechanisms work behind the scenes, and how to optimize applications for better performance.

Speakers

Shaghayegh Tavakoli

Site Reliability Engineer, IONOS

Site Reliability Engineer with 6+ years of experience in scalable infrastructure and Kubernetes automation. Passionate about Linux, networking, and open source. I love exploring system internals, observability tools like eBPF, and building reliable, secure systems using Python, Ansible... Read More →

Tuesday August 26, 2025 16:35 - 16:45 CEST
G102-103

Linux

Audience Experience Level Beginner