We are pleased to announce the the Devicetree Microconference has been accepted into the 2018 Linux Plumbers Conference!
Devicetree provides hardware description for many platforms, such as Linux [1], U-Boot [2], BSD [3], and Zephyr [4]. Devicetree continues to evolve to become more robust and attempt to provide the features desired by the varied users.
Some of the overlay related needs are now being addressed by U-boot, but there remain use cases for run time overlay management in the Linux kernel. Support for run time overlay management in the Linux kernel is slowly moving forward, but significant issues remain [5].
Devicetree verification has been an ongoing project for several years, with the most recent in person discussion occurring at the Devicetree Workshop [6] at Kernel Summit 2017. Progress continues on mail lists, and will be an important topic at the microconference.
Other Devicetree related tools, such as the dtc compiler and libfdt [7] continue to see active development.
Additional possible issues to be discussed may include potential changes to the Flattened Device Tree (FDT) format, reducing the Devicetree memory and storage size in the Linux kernel, creating new architecture to provide solutions to current problems, updating the Devicetree Specification, and using devicetrees in constrained contexts.
If you would like to contribute to the discussion, please feel free to contact Frank (frowand@gmail.com) or Sean (darknighte@linux.com).
LPC [8] will be held in Vancouver, British Columbia, Canada from Tuesday, November 13 through Thursday, November 15.
[1] https://elinux.org/Device_Tree_Reference
[2] https://github.com/lentinj/u-boot/blob/master/doc/README.fdt-control
[3] https://wiki.freebsd.org/FlattenedDeviceTree
[4] http://docs.zephyrproject.org/devices/dts/device_tree.html
[5] https://elinux.org/Frank%27s_Evolving_Overlay_Thoughts
[6] https://elinux.org/Device_tree_future#Kernel_Summit_2017.2C_Devicetree_Workshop
[7] https://elinux.org/Device_Tree_Reference#dtc_.28upstream_project.29
[8] https://linuxplumbersconf.org/
Happy Labor Day to those celebrating today!
We have had great response to our call for 2018 Linux Plumbers Conference refereed-track submissions.
However it would seem that we are attracting a lot of procrastinators given the number of emails we have received requesting for an extension.
With the long weekend in North America, we are moving the deadline to Sunday September 9th at 10:59 PM (PST).
Now really is your last chance to make your great submission! Do not delay, submit your proposal now!
Android continues to find interesting new applications and problems to solve, both within and outside the mobile arena. Mainlining continues to be an area of focus, as do a number of areas of core Android functionality, including the kernel. Other topics include low memory killer [1], dynamically-allocated Binder devices [2], kernel namespaces [3], EAS [4], userdata filesystem checkpointing and DT [5].
We hope to see you there!
[1] https://lwn.net/Articles/761118/
[2] https://developer.android.com/reference/android/os/Binder
[3] https://lwn.net/Articles/531114/
[4] https://lwn.net/Articles/749738/
[5] https://source.android.com/devices/architecture/dto/
If you would like to contribute to the discussion, please feel free to contact Karim (karim.yaghmour@opersys.com), Todd (tkjos@google.com), Vishal Bhoj (vishal.bhoj@linaro.org), Amit Pundir (amit.pundir@linaro.org), or Kevin Brodsky (Kevin.Brodsky@arm.com).
Use of Linux on battery-powered systems continues to grow, and general energy-efficiency concerns are not going away any time soon. The Power Management and Energy-awareness micro-conference therefore continues a Linux Plumbers Conference tradition of looking into ways to improve energy efficiency.
In spite of significant progress made over the last year on multiple fronts, including but not limited to the enhancements of the scheduler’s load-tracking facility with an improved awareness of the amount of time taken by realtime processes, deadline processes, and interrupt handling in order to improve CPU performance scaling, the work on implementing energy-aware scheduling on asymmetric systems in the kernel (https://lwn.net/Articles/749900/), and the process utilization clamping patch series (https://lwn.net/Articles/762043/), there still are open issues to be discussed and new ideas to consider. This year, the focus is on energy-optimized task scheduling, user space interfaces for passing power/performance hints to the kernel, platform power management mechanisms and power management frameworks.
Specific topics include energy-aware scheduling, per-task and per-cgroup performance hints, timer granularity issues in the runtime PM framework, generic power domains (genpd) framework enhancements, firmware-based and direct control of low-level power management features of computing platforms, a proposed on-chip interconnect API, and improving selection of CPU idle states.
If you would like to contribute to the discussion, please feel free to contact Rafael (rafael@kernel.org) or Morten (morten.rasmussen@arm.com).
We hope to see you there!
Core counts keep rising, and that means that the Linux kernel continues to encounter interesting performance and scalability issues. Which is not a bad thing, since it has been fifteen years since the “free lunch” of exponential CPU-clock frequency increases came to an abrupt end. During that time, the number of hardware threads per socket has risen sharply, approaching 100 for some high-end implementations. In addition, there is much more to scaling than simply larger numbers of CPUs.
Proposed topics for this microconference include optimizations for mmap_sem range locking; clearly defining what mmap_sem protects; scalability of page allocation, zone->lock, and lru_lock; swap scalability; variable hotpatching (self-modifying code!); multithreading kernel work; improved workqueue interaction with CPU hotplug events; proper (and optimized) cgroup accounting for workqueue threads; and automatically scaling the threshold values for per-CPU counters.
We are also accepting additional topics. In particular, we are curious to hear about real-world bottlenecks that people are running into, as well as scalability work-in-progress that needs face-to-face discussion.
If you would like to contribute to the discussion, please feel free to contact Daniel (daniel.m.jordan@oracle.com), Pavel (pavel.tatashin@microsoft.com), or Ying (ying.huang@intel.com).
We hope to see you there!
We are pleased to announce that the RT Microconference has been accepted into the 2018 Linux Plumbers Conference! The Real-Time patch (also known as PREEMPT_RT) has been developed out of tree since 2004. Although it hasn’t yet been fully merged, several enhancements came to the Linux kernel directly as the result of the RT patch. These include, mutexes, high resolution timers, lockdep, ftrace, RT scheduling, SCHED_DEADLINE, RCU_PREEMPT, cross-arch generic interrupt logic, priority inheritance futexes, threaded interrupt handlers, to name a few. All that is left is the conversion of the kernel spinning locks into mutexes, and the transformation is complete. There’s talk about that happening by the end of this year or early next year.
Topics proposed for this year’s event include how PREEMPT_RT will be maintained when it gets into the kernel, who’s going to maintain it, how do we catch when it breaks, updates to lockdep, addition of selftests, discussions of RT related failures, stable backports, safety critical domains, and more.
If you would like to contribute to the discussion, please feel free to contact Steven (rostedt@goodmis.org) or Julia (julia@ni.com).
We hope to see you there!
Testing and Fuzzing Microconference Accepted into 2018 Linux Plumbers Conference
Testing, fuzzing, and other diagnostics have greatly increased the robustness of the Linux ecosystem, but embarrassing bugs still escape to end users. Furthermore, a million-year bug would happen several tens of times per day across Linux’s installed base (said to number more than 20 billion), so the best we can possibly do is hardly good enough.
The Testing and Fuzzing Microconference intends to raise the bar with further progress on syzbot/syzkaller, distribution/stable testing, kernel continuous integration (https://kernelci.org/), and unit testing (https://media.readthedocs.org/pdf/ktf/latest/ktf.pdf and https://01.org/lkp). The best evidence of progress in these efforts will of course be the plethora of bug reports produced by these and similar tools!
If you would like to contribute to the discussion, please feel free to contact Sasha (alexander.levin@microsoft.com) or Dhaval (dhaval.giani@gmail.com)
Join us for an important and spirited discussion!
The early registration deadline is August 18, 2018, after which the regular-registration period will begin. So to save $150, register for the Linux Plumbers Conference before August 18th!
The Containers Micro-conference at Linux Plumbers is the yearly gathering of container runtime developers, kernel developers and container users. It is the one opportunity to have everyone in the same room to both look back at the past year in the container space and discuss the year ahead.
In the past, topics such as use of cgroups by containers, system call filtering and interception (Seccomp), improvements/additions of kernel namespaces, interaction with the Linux Security Modules (AppArmor, SELinux, SMACK), TPM based validation (IMA), mount propagation and mount API changes, uevent isolation, unprivileged filesystem mounts and more have been discussed in this micro-conference.
There will also no doubt be some discussions around performance to make up for the overhead caused by the recent Spectre and Meltdown set of mitigations that in some cases have had a significant impact on container runtimes.
This year’s edition will be combined with what was formerly the Checkpoint-Restart micro-conference. Expect continued discussion about integration of CRIU with the container runtimes, addressing performance issues of checkpoint and restart and possible optimizations, as well as (in)stability of rarely used kernel ABIs. Another hot new topic would be time namespacing and its usage for container snapshotting and migration.
Please see here for an overview of this microconference. If you would like to contribute to the discussion, please feel free to contact Stéphane Graber (stgraber@ubuntu.com).
We are pleased to announce that the BPF Microconference has been accepted into the 2018 Linux Plumbers Conference!
BPF (Berkeley Packet Filter) is one of the fastest emerging technologies of the Linux kernel and plays a major role in networking (XDP (eXpress Data Path), tc/BPF, etc), tracing (kprobes, uprobes, tracepoints) and security (seccomp, landlock) thanks to its versatility and efficiency.
BPF has seen a lot of progress since last year’s Plumbers conference and many of the discussed BPF tracing Microconference improvements have been tackled since then such as the introduction of BPF type format (BTF) to name one. This year’s BPF Microconference event focuses on the core BPF infrastructure as well as its subsystems, therefore topics proposed for this year’s event include improving verifier scalability, next steps on BPF type format, dynamic tracing without on the fly compilation, string and loop support, reuse of host JITs for offloads, LRU heuristics and timers, syscall interception, microkernels, and many more.
See here for a preview of the proposed and accepted topics. If you would like to contribute to the discussion, please feel free to contact Alexei or Daniel (lpc-bpf@vger.kernel.org).
Detailed Schedule
