We are pleased to announce that the Open Printing Microconference has been accepted into the 2021 Linux Plumbers Conference. Over the years OpenPrinting has been actively working on improving and modernizing the way we print in Linux. We have been working on multiple areas of printing and scanning. Especially driverless print and scan technologies have helped the world do away with a lot of hassles involved in deciding on the correct driver to use and to install the same. Users can now just plug in their printer and do what they need.
Based on the discussions that we had last year, we have been able to achieve the following:
– Significant progress in deciding on the structure of PAPPL – framework/library for developing Printer Applications as a replacement of Printer Drivers.
– Progress on LPrint. Label Printer Application, implementing printing for a variety of common label and receipt printers connected via network or USB.
– Have helped us in giving shape to the Printer Application concept. Sample printer applications for HP PCL printers have been created that use PAPPL to support IPP printing from multiple operating systems. This prototype will help others looking forward to adopting this new concept of Printer Applications. First production Printer Application started from this prototype is the PostScript Printer Application.
Development is in continuous progress, see the state of the art in OpenPrinting’s monthly news posts[6].
This year’s topics to be discussed include:
- Changes in CUPS 2.4.x
- Print sharing changes for mobile
- OAauth support to replace Kerberos
- Printer drivers replaced with Printer Applications
- TLS/X.509 changes
- CUPS in containers
- CUPS 3.0
- Future CUPS development
- Identify support platforms
- Key printing system components
- Discuss integration with Printer Applications and application stores like Snap Store
- Print Management GUI
- Migrating from working with CUPS queues to IPP services
- Handling legacy devices that do not handle IPP services
- Common Print Dialog Backends
- CPDB, CUPS backend.
- Separating GUI toolkits and the print technology support to be independent from each other.
- Printer/Scanner Driver Design and Development
Come join us and participate in the discussion to bring Linux printing, scanning and fax a better experience.
We hope to see you there.
We are very excited to announce that also for 2021 our friends from the GNU Toolchain are going to join the Linux Plumbers Conference with an additional track: the GNU Tools track. The track will run for the 5 days of the conference.
For more information about what types of proposals are accepted, please see the GNU Tools track wiki page.
The call for papers is now open and will close on August 31 2021. To submit a proposal please go to our CFP page and select the GNU Tools Track.
We are pleased to announce that the VFIO/IOMMU/PCI Microconference has been accepted into the 2021 Linux Plumbers Conference. Today’s high speed components commonly utilize the devices that implement the PCI interconnect specification and the system IOMMUs that provide memory and access control between the devices and the system resources. The features of this domain are constantly increasing with such features as:
Last year’s meetup achieved the following:
- A path towards converting the Intel IOMMU driver for it to use DMA-IOMMU was defined
- Support for exposing devices to userspace using either VFIO mdev or userspace DMA was debated and brought a solution forward
- A discussion was held concerning drivers ability to enable PCI capabilities explicitly without current implicit support through the IOMMU drivers so that the number of newly added quirks can be reduced should there be a broken or buggy feature present. This discussion paved the way closer to a working solution
- The groundwork for improving security and management of both the internal and external (“trusted” and “untrusted”) devices was discussed defining changes that have to be completed going forward
- To ease problems with the hot-plug support, two concepts were presented and reviewed: movable BARs and movable bus number. A discourse followed during which the current issues were widely discussed and a possible solution was debated setting a tone for future work
- A proposal put forward to address the lack of endpoint function drivers ability to perform data transfer between the Root Complex (RC) and Endpoint (EP) leveraging the existing VirtIO infrastructure was reviewed and debated, where then a path forward has been identified
- A series of enhancements to IOMMU and VFIO user APIs for guest Shared Virtual Address (SVA) have been discussed with work already pending inclusion into the mainline kernel
This year’s topics to be discussed include:
- VFIO
- Write-combine on non-x86 architectures
- I/O Page Fault (IOPF) for passthrough devices
- Shared Virtual Addressing (SVA) interface
- Single-root I/O Virtualization(SRIOV)/Process Address Space ID (PASID) integration
- PASID in SRIOV virtual functions
- Device assignment/sub-assignment
- IOMMU
- IOMMU virtualization
- IOMMU drivers SVA interface
- I/O Address Space ID Allocator (IOASID) and /dev/ioasid userspace API (uAPI) proposal
- Possible IOMMU core changes (e.g., better integration with device-driver core, etc.)
- PCI
Come and join us in the discussion in helping Linux keep up with the new features being added to the PCI interconnect specification.
We hope to see you there.
We are pleased to announce that the File System Microconference has been accepted into the 2021 Linux Plumbers Conference. File systems are key to any operating system, and especially for the Linux kernel. They are the gateway to the underling storage, or could simply live in RAM as a virtual information repository. The file system developers are constantly adding features and improvements. Some of these new features are slow to be utilized by the application developers, or they may be used in interesting ways that the file system developers never thought of.
This year’s topics to be discussed include:
- DAX – are we finally ready for prime time?
- Optimizing for cloud block devices. How do we deal with unstable transport? Do we need to rethink our IO path?
- Atomic writes, and FIEXCHANGE_RANGE
- Writeback throttling – we have a lot of different solutions, are we happy with the current state of affairs?
- Page Folios
- RWF_ENCODED
- Performance testing
These are big ongoing projects that have implications across all file systems as well as users, and would be good to discuss across a large portion of attendees.
Come and join us in the discussion of improving the state of saving reading and accessing your data.
We hope to see you there.
We are pleased to announce that the Testing and Fuzzing Microconference has been accepted into the 2021 Linux Plumbers Conference. In spite of the huge number of products shipping with the Linux kernel which are being thoroughly tested by OEMs and distribution providers, there is still no enforced quality standard upstream. How can we make best use of all the publicly available infrastructure and test frameworks in order to fill this gap? Testing and fuzzing upstream as well as gathering results from products is crucial to keeping a project that has over 5,000 commits every month stable for all to use.
Last year’s meetup achieved the following:
- KernelCI enabled LLVM=1 Clang builds and produced initial results from kselftests and real-time tests
- KCIDB achieved multiple integrations, acting as a central collecting point for KernelCI, CKI, syzbot, etc.
- KFENCE was successfully merged.
- Clang: CFI, weeding out issued upstream, etc.
- KUnit started acting as the standard for some drivers.
This year’s topics to be discussed include:
- KernelCI: Extending coverage and improving user experience.
- Growing KCIDB, integrating more sources.
- Better sanitizers: KFENCE, improving KCSAN.
- Using Clang for better testing coverage: Now that the kernel fully supports building with clang, how can all that work be leveraged into using clang’s features?
- How to spread KUnit throughout the kernel?
- Testing in-kernel Rust code.
Come and join us in the discussion of keeping Linux being the best quality it can be.
We hope to see you there.
We are pleased to announce that the Real-time Microconference has been accepted into the 2021 Linux Plumbers Conference. Since 2004, the project that has become known as PREEMPT_RT, formally the real-time patch, has improved the real-time and low-latency features of the Linux kernel. Over the past decade, many parts of PREEMPT_RT have been included into the official Linux codebase. Examples include: mutexes, high-resolution timers, lockdep, ftrace, RT scheduling, SCHED_DEADLINE, RCU_PREEMPT, generic interrupts, priority inheritance futexes, threaded interrupt handlers, and more. The number of patches that need integration has been significantly reduced, and the rest is mature enough to make their way into mainline Linux.
The following accomplishments have been made as a result of last year’s microconference:
This year’s topics to be discussed include:
- New tools for PREEMPT_RT analysis.
- How do we teach the rest of the kernel developers how not to break PREEMPT_RT?
- Stable maintainers tools discussion & improvements.
- The usage of PREEMPT_RT on safety-critical systems: what do we need to do?
- Make NAPI and the kernel-rt working better together.
- Migrate disable and the problems that they cause on rt tasks.
- It is time to discuss the “BKL”-like style of our preempt/bh/irq_disable() synchronization functions.
- How do we close the documentation gap
- The status of the merge, and how can we resolve the last issues that block the merge.
- Invite the developers of the areas where patches are still under discussion to help to find an agreement.
- How can we improve the testing of the -rt, to follow the problems raised as Linus tree advances?
- What’s next?
Come and join us in the discussion of controlling what tasks get to runon your machine and when.
We hope to see you there.
We are pleased to announce that the Toolchains and Kernel Microconference has been accepted into the 2021 Linux Plumbers Conference. Toolchains are the main part of any development, as they create the executables from the code a developer writes. In order to run efficiently on the operating system, there needs to be a strong understanding of the interface between the application and the kernel it runs on. This microconference is focused on the integration of toolchains and the Linux kernel.
Since last year’s meet up, the following has been accomplished:
- Linux-toolchains mailing list and archive created.
- Rust-for-linux Github org established. Patches move from out of tree module building, to in tree module building.
- CI for kernel builds with LLVM moved to tuxbuild after an unexpected “no more free lunch” from TravisCI.
- LTO support landed in mainline.
- PGO patches sent upstream.
- At least one bugfix sent found via clang-tidy/clang-analyzer, discussions around driving tree wide cleanups via clang-tidy.
- GCC implemented support for asm goto with outputs
- Support for auto-initialized automatics in GCC is being worked out in GCC upstream. This is one of the security features that were deemed as desirable by the kernel last year. Work on the other missing desired security features is WIP.
This year’s topics to be discussed include:
Come and join us in the discussion of making the toolchains work better with the Linux kernel.
We hope to see you there.
We are pleased to announce that the Tracing Microconference has been accepted into the 2021 Linux Plumbers Conference. Tracing in the Linux kernel is constantly improving. Tracing was officially added to Linux in 2008. Since then, more tooling has been constantly added to help out with visibility. The work is still ongoing, with Perf, ftrace, Lttng, and eBPF. User space tooling is expanding and as the kernel gets more complex, so does the need for facilitating seeing what is going on under the hood.
Since the last tracing meetup at Linux Plumbers in 2019, a few accomplishments have come out of it:
- The final design of bootconfig came out, which enables kernel command lines be attached to the init ramdisk.
- Discussion on how to simplify the interface to ftrace histograms from user-space resulted in a SQL like utility (still being worked on, but almost finished). This came from the help of the database folks.
- After several rounds of trying to have perf share PMUs (beyond the hardware limit), another approach was taken to use a BPF based solution that does not need any kernel changes. Now perf can use BPF to aggregate counters.
- Work to natively incorporate ftrace into the babeltrace library has moved forward, although more still needs to be done for it to be completed.
This year’s topics to be discussed include:
- Tracepoints that allow faults. It may be necessary to read user space address, but currently because tracepoints disable preemption, it can not sleep, nor fault. And then there’s the possibilities of causing locking issues.
- Function parameter parsing. Now that on x86 function tracing has full access to the arguments of a function, it is possible to record them as they are being traced. But knowing how to read the parameters may be difficult, because it is necessary to know the prototype of the function to do so. Having some kind of mapping between functions and how to read their parameters would be useful. Using BTF is a likely candidate.
- Consolidating tracing of return of a function. Currently there’s three use cases that hook to the return of a function, and they all do it differently. kretprobes, function graph tracer, and eBPF.
- User space libraries. Now that libtraceevent, libtracefs, and libtracecmd have been released, what tooling can be built around them. Also, improving the libtraceevent API to be more intuitive.
- Improving the libtracefs API to handle kprobes and uprobes easier.
- Python interface. Working on getting the libraries a python interface to allow full tracing from within python scripts.
- Tracing containers. What would be useful to expose on creating and running containers.
Come and join us and not only learn but help direct the future progress of tracing inside the Linux kernel and beyond!
We hope to see you there!
We are pleased to announce that the IoThree’s Company Microconference has been accepted into the 2021 Linux Plumbers Conference. As everyday devices start to become more connected to the internet, the infrastructure around it constantly needs to be developed. Linux is showing up more in products that are not normally considered to be computers, but now need to interact with a central location (cloud). This brings new challenges that need to be addressed.
Last’s years meetup produced the following:
This year’s topics to be discussed include:
Come and join us in some heated but productive discussions in making your everyday devices communicate with the world around them.
We hope to see you there.
We are pleased to announce that the Performance and Scalability Microconference has been accepted into the 2021 Linux Plumbers Conference.
All parts of the Linux ecosystem, kernel and userspace, should account for performance and scalability. The purpose of this microconference is for developers from different projects to meet and collaborate, as the entire stack must perform well for the user to see good results. Because performance and scalability are very generic topics, this microconference focuses on issues that may also be addressed in other, more specific sessions.
The structure will be similar to what was followed in previous years, including topics such as synchronization primitives, bottlenecks in memory management, testing/validation, lockless algorithms and RCU, among others.
Here are some of the outcomes from the last time the event was held in 2018:
- With feedback from the audience, Daniel Jordan was able to get the first steps of his project, formerly known as ktask to parallize CPU-intensive work, merged in mainline as part of the padata parallel execution mechanism. Deferred struct page init is now parallelized on x86 systems.
- During Boqun Feng’s topic on workqueues and CPU hotplug, the audience concluded that the problem under discussion was actually not an issue and a stale comment had misled the community, so a follow-on patch removed part of the initial fix.
- In response to a question from the audience, Mike Kravetz proposed aligning addresses returned from mmap(MAP_ANONYMOUS) calls of at least THP size on THP boundaries, resulting in an RFC patch discussion.
This year’s topics tentatively include:
Come and join us in the discussion of improving performance and scalability of your system.
We hope to see you there.
