A lot has been happening with Union recently, so it is time for another update. As a reminder, Union is a project to build a new style engine for applications that tries to unify all the different ways Qt and KDE applications can be styled.
Union in Plasma 6.7
Image
Union in System Settings
As mentioned in the [spring update], Union had its first release as part of the Plasma 6.7 release. Before release we had some back and forth as the intent was to use it as default for QtQuick applications, but that turned out to not be feasible. Instead, we came up with a solution where we use a proxy style as the widget style, which allows Union to be selected from System Settings. For widgets, we forward the styling to the Breeze style still, but when you select the Union style, QtQuick applications will (after restarting the application) use Union for their styling.1
This allows anyone with Plasma 6.7 to opt-in and test how well Union works with their favorite applications, with an easy way to go back should things not work correctly. We already received several bug reports of things not working quite correctly, most of which have been resolved. If you have not yet checked how well Union works for you, give it a try!
Styles and Style Selection
The above solution for selecting Union is mostly intended as an easy way to test Union with Plasma 6.7. It is not meant to be a long-term solution. Instead, we want applications to use Union by default, with a page in System Settings that allows selecting which Union style to use. Initially, that page and the current Application Style will live side-by-side in some form. Once there are a lot more Union styles, we can look at dropping the current Application Style page or moving it somewhere less prominent.
Creating a style selection page required some extra work to make sure that we are able to correctly identify styles and associate metadata with those styles. This work has recently completed, resulting in a fairly big overhaul of the core style loading of Union. Unfortunately, this does mean any styles that have been created so far will need conversion to the new format. The advantage is that now the style determines what input format is needed for the style, which leads to reduced code, increased robustness and easier backward compatibility in the future.
Image
A screenshot of the in-development style selection page for Union.
With Union now having a proper definition of what constitutes a "style", it became fairly straightforward to build a System Settings page to allow selecting the active style. The first version is mostly a copy of the current "Application Style" page, but this will evolve over time as that design is not ideal for what Union is capable of. In addition to the System Settings page, there is also a command-line tool to make it easier to work with Union's styles.
Widgets
Image
The Oxygen Demo application running using the in-progress Qt Widgets support of Union.
Over in Qt Widgets land, Akseli Lahtinen has been chipping away at building a proper Qt Widgets style for Union. This is slow going, as there is little documentation on how to actually work with the QStyle API and it is also showing its age.
Still, progress is being made. At this point, the Union widgets style is no longer a proxy style, with everything being rendered by Union itself. Things are starting to look similar to both the Qt Quick side and to the Breeze QStyle. We are unsure if the work will be finished by the time Plasma 6.8 is released, but we are certainly trying to get it there.
Image
A very much work in progress screenshot of Dolphin running with the Union Qt Widgets style.
Other
There have been several discussions with regards to what capabilities Union needs to have to make it possible to support other styles. This includes discussions around porting Oxygen over to Union to increase the compatibility of Oxygen with Qt Quick applications. There is also ongoing work to build the new Ocean style using Union.
Hopefully with Plasma 6.8 we can move things from being in a tech preview state to become a core part of KDE's experience. But there is still a lot of work ahead of us. If you would like to help get things done, take a look at the Union repository or come talk to us over on Matrix.
Want to make a meaningful contribution to KDE beyond coding? Help us organise Akademy 2027!
Every year, Akademy brings together KDE contributors, users, partners, and the wider Free Software community to collaborate, learn, and innovate. Now it's your chance to help shape the next Akademy by hosting it in your city.
We are looking for proposals to host Akademy 2027 during June, July, August, September, or October. Download the Call for Hosts guide and submit a proposal to host Akademy in your city to akademy-proposals@kde.org by October 1, 2026.
Have questions? We'd love to help! Whether you need advice, guidance, or support while preparing your proposal or organising the event, the Akademy team is here for you every step of the way.
Let's work together to make Akademy 2027 an unforgettable event!
Today KDE releases a bugfix update to KDE Plasma 6, versioned 6.7.4.
Plasma 6.7 was released in June 2026 with many feature refinements and new modules to complete the desktop experience.
This release adds three weeks' worth of new translations and fixes from KDE's contributors. The bugfixes are typically small but important and include:
In the feedback about dropping X11 support, one very surprisingly common comment is from users saying they "need" kgamma, a simple tool that allows the user to adjust the gamma, red, blue and green that gets drawn to the screen operating directly on the X server.
On our Wayland session we have colour management that blows simple gamma adjustment out of the water, so on the face of it it seems weird that this would come up. However at the same time, I get it. ICC profiles are very confusing and it's not the same as a few basic sliders that anyone can understand.
We want people to have the best transition to Wayland we can offer and this is a relatively easy fix.
The new tool
I have made a simple tool that edits the relevant part of an ICC profile - VCGTs.
"VCGT (Video Card Gamma Table): An optional, private tag inside an ICC file that stores 1D grayscale/gamma curves loaded directly into your graphics card's hardware Look-Up Table (LUT)."
That's a lot of fancy terms, but the key point is it's a tiny subset of the thing Kwin already supports. We can add a UI around those few values and not need to add a second code path in kwin or kscreen.
The UX is deliberately similar to the old UI.
Obviously it needs a round of polish (volunteers welcome!), but it's functional.
Why this is even better than on X11
Unlike KGamma on X11, this new tool:
Supports multiple monitors with independent values
Works with night colour rather than fighting over the same settings, Kwin will blend the two sets on top of each other
Gets applied by Kwin on startup so the first frame is perfect, rather than glitching during loading
What next
Whilst changing your red/green settings wtih sliders might be something a few users do, and we got a few comments it remains a niche case.
My intention is to post it as a standalone application on Flathub and not as part of Plasma. I think that strikes the right balance of providing support without holding ourselves back longterm.
Welcome to the inaugural edition of This Month in KDE Linux hosted on blogs.kde.org!
Previously, these posts lived on Nate Graham's personal blog. But KDE Linux is growing up and becoming a more important part of KDE, larger than its individual contributors! So it's time to move the public communication to KDE infrastructure, and that's where you'll be able to read these posts going forward.
Without further ado, here's how KDE Linux evolved in July:
QA & testing
This month, Thomas Duckworth and Bhushan Shah integrated the next-gen QA system they've been building!
It's now testing tons of conditions to make sure KDE Linux continues to work as expected, and it also acts as a full-stack integration test suite. To illustrate the utility of such a thing, it's already identified and protected users from two significant issues:
Hadi then made this work for Java apps; the first time you try to launch one, the tool will ask you if you want to download a Java Runtime Environment (JRE). If you approve, it will do so and then launch the app using the JRE:
After that, Hadi implemented support for DOS apps; trying to launch one will offer up DOSBox. Now you can have that authentic 1993 Doom experience:
This system can be extended to support even more things in the future! And it's been written in a generic enough way that it would be useful for any other image-based OS using Flatpak, as well.
WenChao Zhang restored the esp4 and esp6 kernel modules that had been removed to mitigate the "DirtyFrag" vulnerability. The vulnerability has been fixed now, and missing those modules had broken IPsec VPNs, so they're back now.
Hadi Chokr documented how to set up bootloader menus so you can choose between booting KDE Linux or another OS on the same computer. However, setting up such a system is left as a manual exercise for the reader, as currently the KDE Linux installer does not yet formally support complex disk setups. This will come later.
Grab bag
Prajna Sariputra pre-installed vulkan-virtio, improving performance in VMs whose graphics drivers support Vulkan.
for the past few months i have been working on implementing rich text in drawy as part of google summer of code 2026.
Overview on the old implementation:
The old text logic depended on a manual implementation, almost everything was built from scratch using a string. Placing the cursor, caret movement, selection operations, line and word boundary detection, editing operations were all implemented from scratch.
I found implementing all of this impressive, but while it worked for plain text editing, this code was hard to maintain / extend, and it would have been nearly impossible to add the features that were added.
Phase 1: Refactoring Goal: Rewrite without breaking anything
I replaced the string with QTextDocument , all the things that were written manually before was gone and now editing operations are handled by QTextCursor.
Operation
How it was done
How it is done now
Placing cursor
Binary search over the line, measuring substring widths with QFontMetrics to find which character the click landed on.
documentLayout()->hitTest()
Caret movement
Manual index calculation increment/decrement; up/down walked to the previous/next \n
Two indices, with selection rectangles rebuilt line-by-line using QFontMetrics
QTextCursor anchor/position, drawn via QAbstractTextDocumentLayout::Selection
Word/line boundary detection
Manual scan for separator characters or \n
cursor.select(WordUnderCursor / LineUnderCursor)
Phase 2: Rich Text
1. adding IME support
An Input Method Editor (IME) is how the OS handles input for languages that can't be typed with a single key press per character without it user can't type with Arabic, Japanese, Chinese, dead keys, etc The OS sends this as a QInputMethodEvent, which Drawy previously didn't handle. IME now works correctly here is demonstration of how it works with CJK input:
text history is managed by two stacks: drawy global stack, and QTextDocument's internal one. Only one is active at a time. While the user is editing text, the global stack is disabled and QTextDocument's internal stack takes over, handling text edits and property changes, etc. Once the user exits edit mode, the internal stack is disabled again, any changes go through Drawy's global stack instead, stored as HTML.
5. Spell checking
In my proposal, I didn't plan much time for spell checking, I thought that I'd just wire Sonnet in and be done with it. I later found out that Sonnet's ready-made integrations are built for QTextEdit and QML, so I had to write my own spell-checking pipeline instead.
Each block (paragraph) is passed to Sonnet::gusser to guess its language and determine which dictionary to use.
Text is split into words using QTextBoundaryFinder.
Sonnet::Speller checks whether each word is misspelled.
Misspelled words are highlighted using QSyntaxHighlighter.
added new menu to settings using Sonnet::ConfigWidget to allow customizing spell checking:
Note: Everything mentioned in this blog is on thegsoc2026branch currently and will be merged once GSoC is completed.
Gratitude:
I am very grateful to my mentor Laurent Montel for his time and effort guiding me throughout this project.
Time for another bi-monthly update on what happened around Itinerary! Since the previous report there's a new combined journey view, support for ride sharing services and new Apple Wallet pass formats, among many other things.
New Features
New combined journey view
With more and more journeys being backed by online realtime and schedule data, access to the journey details (intermediate stops, journey map view, etc) via nested actions has become increasingly cumbersome. Therefore Jonah redesigned the details pages for all transport entries (trains, buses, ferries, flights) to have a new bottom toolbar to easily access that information.
New tabbed journey details view.
The journey details view now also allows to query public transport departures at any intermediate stop, which is useful e.g. when doing manual rerouting in case of more complex disruptions.
Ride sharing
After Transitous got support for ride sharing earlier this year, this has now also reached out client applications. Both Itinerary and KTrip have a mode filter for this now, and Itinerary can add ride sharing trips to the timeline.
Mode of transportation filter options.
New Apple Wallet pass formats
Itinerary can now display a new variant of the Apple Wallet pass format, so-called "poster event tickets". Conceptually those are similar to the existing event tickets but have very different layout and content, which wouldn't render at all so far.
Test pass with the so-called poster event ticket layout.
The background blur effect and some of the font sizes are still off, but at least the relevant content is now displayed correctly.
There's also a few format additions affecting all pass types that are now supported:
Four additional barcode types (EAN13, Code 39, Codabar and ITF).
Multi-row auxiliary fields.
RGBA color values.
A few gaps in the existing format support were also fixed while at it:
Correctly displaying date-only and time-only fields.
Finding image assets only existing in a higher pixel ratio variant.
Fixed organization and description fields not being translated.
Besides the visual representation Apple Wallet passes can in newer versions also contain machine-readable semantic information about their content, something that is now used in the travel document extractor as well.
Infrastructure Work
Booking links in Transitous
Thanks to Jonah's work, MOTIS, the routing engine behind Transitous got support for the GTFS Transit Ticketing Extension. This makes booking links available for more operators, which are then shown by Itinerary or KTrip.
Android and Linux platform integration
There has been generic work on platform integration for all of KDE's (mobile) apps, which of course also benefits Itinerary.
For Android there's a dedicated blog post. Since then locale-aware comparisons have been fixed in Qt (for 6.13), and Itinerary got built-in crash reporting that is already helping during development. Some necessary changes to finally fix not being able to open files from cloud shares is still stuck in review though.
For Linux the focus has been on permission checks and GPS access in a Flatpak sandbox (blog post). The foundation for the Qt permission API to support the Flatpak persmission system has been integrated meanwhile, for Qt 6.13.
Indoor OSM standardization
There also have been efforts on evolving and standardizing modelling and mapping of indoor spaces in OpenStreetMap. While that is of course done with the entire OSM ecosystem in mind, it also benefits Itinerary, Transitous and Kongress. There it helps with improving routing through buildings and with visualizing building interiors.
GBFS v3 support continued
The previous report had mentioned work on improving the support for GBFS v3 sharing vehicle data. This continued and now also has some more visibile results:
The GBFS feed database has been updated to contain about 1.500 feeds from all over the world, and can now be online updated independent of the application itself.
Rider capacity for vehicles is shown when available (mainly relevant for cars).
Opening hours of rental vehicle stations or rental vehicle networks can now be displayed.
Beginning of October we have the second Open Transport Community Conference in Bern, both the Transitous and the Itinerary community will be present there. A few tickets are still available.
Fixes & Improvements
Travel document extractor
New or improved extractors for 12go, Accor, BDŽ, Collegeboard, Doodle, DRK, Flixbus, HVV, IRCTC, KTMB, PKP, Polferries, Sportio, SRT, Ticketspot and VR.
Fixed extracting return descriptions from standard UIC FCB NRT ticket barcodes (bug 520826).
This has been made possible thanks to your travel document donations!
Public transport data
Allow location searches without explicitly selecting a country.
Improved aggregation and sorting of stop search results.
Added support for Amtrak onboard API.
Added support for resolving locations from coordinates and booking URLs for LTG Link.
Fixed sorting of countries on the backend configuration page.
Fixed DB booking URLs for connections where they don't actually sell tickets.
Fixed displaying text on light line colors with light color schemes.
Fixed timer overflow on timeline updates for trips too far in the future.
Fixed notification configuration when running in a Flatpak sandbox.
The time picker on Linux now has a button to easily select "now".
Fixed France accidentally not being considered part of the EU roaming area.
Show all reserved seat numbers on the vehicle layout page.
How you can help
Feedback and travel document samples are very much welcome, as are all other forms of contributions. Feel free to join us in the KDE Itinerary Matrix channel.
…but before we start, here's a quick reminder that we've entered the last week to submit your proposal for the next KDE Goals cycle! If you're not ready to champion a goal, you can still get involved by joining one of the existing proposals as a contributor or supporter.
And now, without further ado…
In addition to the headliner feature and expected UI improvements and bug fixes, this week features some promising technical and performance improvements. Have a look:
Notable new features
Plasma 6.8
You can now make the emojis in the Emoji Selector window bigger or smaller. (Jason Uithol, plasma-desktop MR #3878)
On System Settings' Display Configuration page, you can now move screens pixel-by-pixel using the arrow keys while in layout editing mode. (Antti Savolainen, kscreen MR #476)
Notable UI improvements
Plasma 6.7.4
The Emoji Selector window is now always tall enough to accommodate its sidebar without scrolling. (Christoph Wolk, KDE Bugzilla #523090)
Spectacle now detects QR codes in screenshots that you take in such a manner that the main UI is never shown; if you click "Annotate" from the notification about it, the QR code will be detected there. (Kai Uwe Broulik, KDE Bugzilla #521097)
Plasma 6.8
In Spectacle's settings window, image quality controls are now only available for image types whose quality level is adjustable. (Zhora Zmeykin, spectacle MR #568)
Clarified the instructions on System Settings's Remote Desktop page a little bit. (Nate Graham, krdp MR #224 and krdp MR #225)
Kup 0.11.0
Modernized the UI for the Kup backup system's System Tray widget, so now it matches other Plasma widgets that can similarly show multiple items, each with their own actions. (Bharadwaj Raju and Tomáš Hnyk, kup MR #53 and kup MR #54)
New
Old
Notable bug fixes
Plasma 6.6.7
Fixed a case where the ksystemstats background service could crash seemingly randomly. (Méven Car, KDE Bugzilla #523562)
Fixed a recent regression that made blank document icons appear in the notification history view. (Kai Uwe Broulik, KDE Bugzilla #522846)
Fixed a bug that could make extremely long words in Plasma tooltips overflow rather than wrapping. (Nate Graham, KDE Bugzilla #523614)
Fixed a bug that made third-party widgets fail to inhibit power management more than once. (Vincent de Robert, KDE Bugzilla #523605)
Plasma 6.7.4
Fixed a visual glitch where the highlight area for expanded list items in various System Tray widgets would sometimes be too small to fit its contents. (Bharadwaj Raju, KDE Bugzilla #506295)
Plasma 6.8
Fixed an issue that could sometimes corrupt very large screenshots taken in Spectacle when they were pasted elsewhere. (Cezar Craciunoiu, spectacle MR #566)
Frameworks 6.29
Opening various windows and dialogs using Kirigami components no longer makes the content scroll into view for no particularly good reason. (Manuel Alcaraz Zambrano, KDE Bugzilla #515811)
ddcutil 2.2.8
Fixed multiple issues that could make the powerdevil background process freeze or crash. (Sanford Rockowitz, ddcutil issue #581 and ddcutil issue #587)
Notable in performance & technical
Plasma 6.8
Significantly improved performance with external GPUs. Read more about this on Xaver's blog! (Xaver Hugl, kwin MR #7101)
You can now change the size (and effective resolution) of virtual screens created for screencasting, rather than them being fixed to a resolution of 1920 × 1080 pixels. (David Edmundson, KDE Bugzilla #512620)
Panel floating-ness can now be changed using Plasma desktop scripting. (Ramil Nurmanov, KDE Bugzilla #521549)
KWin now recognizes the "Pick up phone" and "Hang up phone" keys on some keyboards, allowing them to be used in keyboard shortcuts to trigger actions. (Méven Car, kwin MR #7892)
Frameworks 6.29
Fixed a performance issue that could make Plasma freeze when it sent a notification with a lot of emojis in it. (Devin Lin, KDE Bugzilla #508070)
How you can help
KDE has become important in the world, and your time and contributions have helped us get there. As we grow, we need your support to keep KDE sustainable.
Would you like to help put together this weekly report? Introduce yourself in the Matrix room and join the team!
Beyond that, you can help KDE by directly getting involved in any other projects. Donating time is actually more impactful than donating money. Each contributor makes a huge difference in KDE - you are not a number or a cog in a machine! You don't have to be a programmer, either; many other opportunities exist.
You can also help out by making a donation! This helps cover operational costs, salaries, travel expenses for contributors, and in general just keeps KDE bringing Free Software to the world.
To get a new Plasma feature or a bug fix mentioned here
Since I still hear about "microservices" more often than I'd like to. Here is another piece which points the trade-offs and that really there's no one size fits all.
Good approach, you indeed need to immerse yourself in the context and see the recurring patterns. That's the best way to figure out impactful solutions to recurring issues.
Interesting take, it's more than just about hard drives being full. Indeed, there are many things on which we tend to procrastinate. But on the other hand… so many budgets to track otherwise!
Very interesting series I previously missed. It explores if software engineering is really engineering, and the differences with other engineering fields. Quite a few nice lessons to draw from it.
Performance on "secondary" GPUs has historically been suboptimal on Linux, especially with external GPUs. Let's take a look at why it's slow, and how we're finally fixing it.
How Multi-GPU even works
To know how things work with multiple GPUs, we first need to look at how applications present images in single GPU systems.
With Wayland, the linux-dmabuf protocol is used for sharing images from applications to the compositor. The compositor advertises which GPU it's using, and a list of drm formats1 and format modifiers2 it can make use of.
The application then allocates a dma-buf (direct memory access buffer) for each image with one of the supported formats + modifiers on the GPU of the compositor, and sends the compositor file descriptors for these buffers to share them.
This works quite well, but only for single GPU systems. In linux-dmabuf version 5, the compositor can only advertise one GPU as being usable! The app could still attempt to pass the buffer of any GPU to the compositor, but that can fail, requiring fallbacks, and it can cause really big performance issues.
Why it's slow
When you import a dma-buf to a GPU, the kernel tries to be helpful and automatically ensures for you that the GPU you're using can access the buffer. This sounds nice, and can be useful, but it's also the source of all our performance problems.
Let's say you have a laptop with an integrated GPU, and a dedicated GPU. When you start a game on the dedicated GPU, what would happen is
the game allocates a buffer on the dedicated GPU
it passes that buffer to the compositor
the compositor imports the buffer into the integrated GPU
To make step 3 work, the kernel would move3 the buffer to system memory. This can be really terrible for performance, since system memory is terribly slow in comparison to video memory, and the dedicated GPU has to go through the PCIe bus to access it, which has high latency.
To solve that problem, Vulkan and OpenGL drivers compare the GPU the application is using with the one the compositor advertises. If they're not the same, then the driver will not share the buffers on the GPU with the compositor, but actually create a copy in system memory and share that copy with the compositor instead. So this would be
the game allocates a buffer on the dedicated GPU
the driver copies the buffer to another buffer in system memory
it passes that other buffer to the compositor
the compositor imports the buffer into the integrated GPU
Now imagine you're not playing the game on your laptop display, but you have an external display connected to the dedicated GPU. The HDMI port on a lot of laptops is wired to the dedicated GPU, so this is a really common scenario. What happens in that case is
the game allocates a buffer on the dedicated GPU
the driver copies the buffer to another buffer in system memory
it passes that other buffer to the compositor
the compositor imports that other buffer into the integrated GPU
the compositor composites with the integrated GPU
the compositor copies the composited result to the dedicated GPU
So your game gets copied to system memory and back to video memory, for no real reason. The performance hit caused by that isn't great in general, but it gets so much worse with external GPUs.
When all you have is one USB C cable to transfer data from and to the GPU, with high resolution monitors the bandwidth of that cable can be too small even for copying in one direction! Going in both directions completely kills performance. For example, I have a setup with
a Framework laptop 13
a rx 5700 XT in an external GPU enclosure
a 5120x1440 monitor at 120Hz connected to the external GPU
If I start vkcube (a super simple test app) on the external GPU, move it to the monitor and make it fullscreen, it only reaches 55fps!
How to fix it
In principle, we "just" need to stop the driver from copying the buffer around, and instead have it pass the original buffer from the dedicated GPU to the compositor. That's exactly what I proposed version 6 of the linux-dmabuf protocol for: The compositor can support a list of GPUs instead of just one, and the application can tell the compositor which GPU it should import a given buffer into.
This all sounds nice and simple in theory, but as always, it wasn't quite that simple in practice. There are basically three problems that needed to be solved for this change to be useful:
the driver needs to not do the copies unless actually necessary
the compositor needs to do the copies when required
to actually get any performance gains, the compositor needs to skip the copies whenever possible
Thankfully, I didn't need to do this alone. Victoria Brekenfeld from System76 implemented support for the protocol in Mesa and Smithay, the library used by the cosmic compositor.
Unfortunately, it took a long time to support the protocol in a useful way in KWin. I needed to make it
aware of multiple GPUs beyond just displaying on them
properly handle GPU hotplug with that new infrastructure
deal with all the weird GPU setups in embedded systems
track which GPU each buffer is on
have generic multi GPU copy infrastructure
make those multi GPU copies actually as fast as the copies Mesa does internally
deal with GPU resets correctly while doing multi GPU copies
actually implement the Wayland protocol bits
Some of this was just moving code from out drm backend to more generic places, but a lot of it required doing things from scratch. Especially GPU reset handling was challenging because KWin's effects APIs make a lot of assumptions about OpenGL contexts and didn't support just stopping rendering a frame once it started.
While working on this, I also added Vulkan support to KWin specifically to make the multi GPU copies as fast as possible, which also took some time. As a positive side-effect though, we now have basic Vulkan infrastructure in KWin that can be used for a future Vulkan renderer.
Finally, just over 2 years after I first proposed the protocol, we had complete enough implementations to prove it works as expected and the protocol was merged. Since then, the KWin implementation was merged, the Mesa implementation should be merged soon and Nvidia has an (as of time of writing, unreleased) implementation of the protocol in their driver as well.
The actual performance gains
So, how much does this actually help? With vkcube, we go from 55 fps to the full 120 fps of the monitor, but that's hardly a practically relevant test.
So I fired up Cyberpunk 2077 with the "low" graphics preset and it went from 27 fps with Mesa main to 50 fps with linux-dmabuf v6. That's more than 80% better performance!
Mesa main
Mesa with dmabuf v6
From playing around a bit with the graphics settings, it seems likely that the game is bottlenecked by the USB C bandwidth, so the performance uplift could be even better with additional driver optimizations.
I haven't been able to benchmark the impact of dmabuf v6 on "normal" laptop setups, because I don't yet have access to a Nvidia Vulkan driver version implementing the protocol, and I don't have a laptop with a dedicated AMD GPU. If I had to guess though, I'd expect improvements there to be much more moderate, probably something in the 5-10% range. I'll update this post once I know more.
However, this performance uplift comes with two big caveats…
When does this work?
With the current KWin implementation, compositing always happens on the "primary" GPU. On laptops, by default that's whatever GPU the internal display was connected to when KWin started. This means you can only get those large benefits if the game gets direct scanout.
My rx 5700 XT doesn't have support for color pipelines, so I only get the performance benefit if HDR is disabled, night light is disabled and no color profile is used. I already have a merge request to lift that restriction though, stay tuned for part 2 to find out more about that!
There is another caveat though, and that's a far bigger challenge: Most games still run on X11, and implementing the protocol (in a useful way) in Xwayland is incredibly challenging because of some assumptions X11 makes. I don't know how that could be fixed, or even if it's feasible at all, so for now, you can only get these benefits with games using Wayland directly.
For a lot of native games, using SDL_VIDEODRIVER=wayland does the trick, and for most Windows games, you can use Proton forks with the Wine Wayland driver. In my experience, Wine Wayland works really well and even HDR just works™ with it nowadays.
drm formats describe how the memory in the buffer is used, like "16 bits red", "8 bits red, 8 bits green, 8 bits blue, 8 alpha bits" or similar ↩
format modifiers (more or less) describe how the pixels are laid out in memory ↩
meaning, it will create a copy, and then delete the original ↩
We are happy to announce the release of Qt Creator 20.0.1!
The release improves tool detection and the default session directory for chats in the AI Agent Client Protocol integration, fixes various issues with CMake Presets as well as some crashes, and contains various other improvements.
Today we're releasing Krita 5.3.3 and 6.0.3, containing many bugfixes and improvements across the board.
Android Donations and Supporter benefits
On Android, version 5.3.3 lets you support Krita's development directly through the application. This goes through the Play Store, so if you have a device without Google services or are using a debug or nightly version of Krita, it won't be available and instead will show you donation links.
In return for supporting Krita, you'll be able to download resource bundles directly in the application, including the paid Digital Atelier bundle. The splash screen and welcome page will also tell you about the supporter packs or donation links. You are not required to make any purchases, no features are locked behind a paywall and you won't get nagged about it while you're actually working. You can also of course still manually import resource bundles, the downloads are just a convenience feature.
Special thanks to Freya Lupen and Elena Sagalaeva, for multiple bug fixes, as well as the many newcomers who contributed to this release (named in the changelog).
Don't free hold frame undo command at scope exit (Bug 520732)
Added get started, community, website and source code icons (Thanks to Arkady Flury)
Try removing shell=True from the python calls on Windows
Get rid of division by zero in the KisMplTest.( Thanks to Elena Sagalaeva)
[android] All animation export and import functionality has been removed for now. Mostly because these functions didn't do anything. We're working on a properly working replacement for Android specifically.
Delete QuaZipFile before deleting the archive (Bug 520362)
Fix layers getting deselected when starting transform (Bug 517590)
Ensure a layer is activated for new views (Bug 518465 , Thanks to Gregg Jansen van Vuren)
Fix FFmpeg 7.0+ to render HDR animations (Bug 520669)
Fix Out-of-Bounds-Selection-Inversion (Bug 518235, Thanks to Ricky Ringler)
Fix Display Selection action check stats
Fix crash on null event pointer in Abstract Input Action (Bug 520581)
Force non-var vertical metrics to use default vertical caret. (Bug 517717)
Fix font-family sorting for fonts with wwsWithoutName set mixed.(Bug 518874)
Try to deduplicate font family names better, so we don't get sql errors. (Bug 517361)
Fix bug 522430. Switching between frames should always complete. (Bug 522430)
Fix deadlock when doing perspective transform (Bug 520602)
Expose tool and brush change signals to PyKrita (Thanks, Moritz Staudinger)
Various fixes to the selection action panel, including the ability to stick it to the sides of the canvas by pressing the "pin" icon.
Various fixes to the comic panel editing tool functionality.
Allow higher resolution of thumbnails on Welcome Screen.
⚠️ Warning
We consider Krita 5.3.3 suitable for productive work; 6.0.3 is, because of the many changes from Qt5 to Qt6 more experimental.
Download 5.3.3
Windows
If you're using the portable zip files, just open the zip file in Explorer and drag the folder somewhere convenient, then double-click on the Krita icon in the folder. This will not impact an installed version of Krita, though it will share your settings and custom resources with your regular installed version of Krita. For reporting crashes, also get the debug symbols folder.
The Linux AppImage and the source tarballs are signed. You can retrieve the public key here. The signatures are here (filenames ending in .sig).
Download 6.0.3
Windows
If you're using the portable zip files, just open the zip file in Explorer and drag the folder somewhere convenient, then double-click on the Krita icon in the folder. This will not impact an installed version of Krita, though it will share your settings and custom resources with your regular installed version of Krita. For reporting crashes, also get the debug symbols folder.
I attended the GSoC Alumni Camp in Delhi, it was an amazing opportunity to make people who are already familiar with open source aware of KDE Community and I was actually able to do that. The event itself was from 8:00 A.M. to 10:30 P.M. at night. The event started off with a formal opening session. Soon after was the scavenger hunt (we were hunting people!) it was a 5x5 grid where you needed to get signatures of people who fit the question in the box. A few of them were :
I was born in July (I signed a lot of them )
I have held a koala
I know 3+ languages
I can juggle
I prefer go/Rust and so on. In all honesty it was an amazing ice breaker and something to get to know people. After that there were a few unconferences followed by lunch and then more unconferences till 6:00 P.M. after that lightning talk sessions started and fortunately I got to represent KDE.
Unconference Session - From GSoC Student to Maintainer/Mentor
I also hosted one of the first unconference sessions titled:
From GSoC Student to Maintainer/Mentor
I wasn't expecting a large audience, but at one point the room was at its capacity around 40 attendees.
The audience included:
GSoC Organization Administrators
Mentors
Open source employees
Existing contributors
Google code-in students
The discussion focused on contributor retention after GSoC and how organizations can better support contributors beyond the program. It led to some interesting discussions where we found out what some organisations are doing.
Discussion Points (Noted by an org admin)
Leverage Contributors as Subject Matter Experts
GSoC contributors naturally become subject matter experts for the components they build. When new issues, bug reports, or pull requests relate to their work, proactively invite them to participate in the discussion or review. This helps contributors feel that their expertise is valued and keeps them engaged with the project beyond GSoC.
Improve Communication Around Pull Request Reviews
Complex pull requests often require focused reviews and may take longer than isolated bug fixes. While taking the necessary time for a thorough review is important, mentors should acknowledge review requests and, where possible, communicate an expected timeline. Even a brief acknowledgment improves the contributor experience.
Using Organization Stipends for Contributor Retention
Explore using the GSoC organization stipend to support promising contributors after the program ends. This could fund continued maintenance or feature development through a transparent platform such as Open Collective, allowing contributors to invoice for their work and remain actively involved with the project.
Recognizing Mentor Contributions
Mentoring requires a significant investment of time in reviewing code, guiding contributors, and providing technical support. Consider allocating a portion of the organization stipend to compensate mentors, recognizing their efforts and encouraging long-term participation.
KDE's Community Support
Another topic that generated considerable interest was KDE's support for its contributors.
I talked about how KDE sponsors some students to attend Akademy, and how I was also sponsored to attend the event, which a lot of people agreed organizations should've done (some did, a lot didn't) but a lot of people agreed that when an organization consider these things contributors stay.
After all the unconferences ended a lot of people came up to me saying mine was the best and I managed and engaged everyone in the best way possible ( I was on cloud 9).
Lightning Talk
One of the highlights was being selected to give a lightning talk. Only 18 participants were chosen, and I was one of them.
My GSoC project Join KDE is an advertisement for KDE itself, so the project itself became an easy conversation starter. It was a great opportunity to introduce KDE and make more people aware of the organization.
Although I did fumble the last part of my presentation it was more of me being confused where my slide went (some slides were misplaced) aside from that it went as any other informative talk but hey I was funny on the stage (refer to the pics) so people remember me! You win some you lose some, oh well.
Conversations Throughout the Event
Outside the sessions, I had some interesting discussions with contributors from different organizations. Some contributors showed interest in working wwith us while some showed interest in our eduction/science side but honestly it's hard to bring contributors over as they're in different domains, org admins/mentors or they're busy with their careers.
SU2 Foundation
I had a conversation with a maintainer from the SU2 Foundation, whose work focuses on computational fluid dynamics.
We discussed KDE's scientific and educational initiatives, including KDE for Scientists and several education-related projects. I also shared the KDE For You website as an introduction to the wider KDE ecosystem.
After Party
The conversations continued during the after-party on the following day.
I met a group of students who had become interested in open source after interacting with contributors throughout the event. They had originally attended as friends of another contributor.
One of them is now actively looking for a project to begin contributing to within KDE. YAYYY!
New Contributors
Several first-time contributors approached me asking about projects suitable for beginners.
I introduced them to a number of KDE projects and explained possible contribution paths.
But the same issue they're busy with the beginning of their careers.
Overall Thoughts
The Alumni Camp was one of the best ways to make people aware of KDE and I tried my best while i had fun ( we played uno there! Will bill the cards to the organization jkjk), a lot of people seemed intrigued and asked me to share some stuff about KDE to them or they'll try it on their own. Met someone from GNOME (they didn't get any lightning talk HA! I know, I know no inter project fighting that's bad) had some good conversations, teased the person from GNOME, had breakfast with them, and tried to make the most of the unconference session and the lightning talks to at least get people to know the name KDE!
There is a bug in KDE's bug tracker that is almost as old as some of our contributors: bug 342056, "Ridiculously slow file copy (multiple small files)", reported by Alexander Nestorov back in 2014. The report is blunt: copying a 15 GB folder of roughly 3 million small files took 5 to 10 hours in KDE, versus about 20 minutes with rsync. One commenter summed up the mood:
I generally use cp and rsync instead of dolphin for anything more than a few files.
That bug has been stuck in my head for a while, so this post is about finally fixing it. I have been working on KIO's copy path, and I want to walk through where the time was going, some history that explains why, and show numbers across KIO versions including a plain cp for reference.
At with any optimization, let's measure first:
Where a KIO 6.28 copy of 5000 small files spends its blocking time, and there is no single hotspot. Each file blocks in a burst of short syscalls: reading the mount table (/proc/self/mountinfo), opening the source and destination, and round-tripping a command to the worker over an internal socket. The socket round-trips, the send and receive plus the waits for each reply, are the frames highlighted in red, about 15% of the blocking here, spread as thin slivers across both threads because every one of the thousands of files pays them. The frames in green are the real filesystem work the copy cannot avoid: the statx and openat calls, copy_file_range moving the bytes, and the ext4 metadata updates beneath them. That per-file storm, not any single call, is what the rest of this post discusses. (Off-CPU flame graph from sched:sched_switch, weighted by number of blocking switches; click to open the full SVG.)
A little history
KIO is the layer behind almost every file operation in KDE software, from Dolphin's copy and paste to the network transparency that lets you open sftp:// or smb:// URLs as if they were local. Its design goes back to the KDE 2 days, around the year 2000. Back then the answer to "how do I do I/O without freezing the UI" was not a thread but a separate process: a worker (we used to call them kioslaves) is launched for a protocol and talks to the application over a socket. This predates usable threading on Linux (Native POSIX Thread Library only landed in Linux 2.6 in 2003), so processes plus socket IPC was the portable, robust choice, and it still is for network protocols today: if an smb:// worker crashes, your file manager does not go down with it.
The flip side is cost. Every request and its reply are serialized and sent over that socket, with an event-loop hop on each side. For file:// that overhead buys you nothing, because there is no untrusted network on the other end, just the local disk.
In 2022 David Faure changed that: Implement running KIO workers in-process using a thread landed in Frameworks 5.95. Since then the file worker runs on a thread inside the application instead of as a separate process (other protocols stay out-of-process for robustness). That removed process launch and context-switch cost.
No socket between the thread and the app (6.29)
There was still a catch that had been hiding in plain sight: even in-process, the worker thread and the application talked to each other over a socketpair, serializing every command as if they were separate processes. Once the thread was used, that socket was pure overhead.
That's the red highlight in the first flamegraph.
So in-process workers now use a real in-memory transport instead of a loopback socket. A new ThreadConnectionBackend handles commands, and for reads the actual data buffer, straight to the peer thread, with no serialization and no syscall, which makes in-process file reads zero-copy. This is the biggest single jump in the numbers below, and it has landed on master for 6.29 (kio!2279).
Next: batching the copy and the stat (under review)
The changes above make each command cheap. The remaining cost is that there are still so many of them: copying N files is N separate file_copy jobs, each one going through the job scheduler and taking its own round-trip to the worker. For many small files that fixed per-file cost, not the data, is what dominates.
CopyJob can dispatch a whole batch of plain local-to-local files to the worker in one command, and the worker copies them (using copy_file_range, and reflink on filesystems like Btrfs or XFS that support it). Each file still gets its progress signal, its byte accounting, its undo entry, and anything the worker cannot do blindly - an existing destination, an unreadable source, a rename or skip decision - is handed back to the normal per-file path. The gate is conservative on purpose so a hung mount can never freeze the batch (kio!2282).
The same copy on 6.29 with batch-copy: the red socket round-trips are gone. Two things removed them: the in-memory transport from the previous section (no socketpair at all) and batch-copy folding a whole run of files into one command instead of one round-trip each. What is left is real filesystem work: the green frames are the copy itself, copy_file_range moving the bytes, the openat and statx calls, and the ext4 metadata beneath them. The wide plateau that is not green is the benchmark loop deleting each pass's files before the next run (unlink), which is teardown rather than part of the copy.
Before copying, CopyJob stats every source, which is another per-file round-trip. The follow-up batches the stat phase over the same in-process lane. This is the batch-copy-stat column below.
Both of these are under review and targeted at a release after 6.29, so treat their columns in the table as a preview of what is coming rather than something you can install today.
Numbers
Methodology: a 13th-gen Intel Core i7-1365U laptop, everything built RelWithDebInfo without any sanitizer, copying onto a real ext4 volume (so no reflink shortcut, copy_file_range moves real bytes). Each KIO version supplies both its own libKIOCore and its own kio_file worker. Times are the median of 5 runs (3 for the large set) after a discarded warm-up, so caches are warm and equal for every version. cp -r --preserve=mode,timestamps is included as the floor, since that is what the bug reporter reached for instead of Dolphin.
5000 files of 4 KB each (the many-small-files case from the bug):
Version
Median time
cp -r (coreutils)
81 ms
KIO 6.28.0
1616 ms
KIO 6.29-dev (master)
396 ms
KIO 6.29-dev + batch-copy
88 ms
KIO 6.29-dev + batch-copy-stat
93 ms
1000 files of 5 MB each (bulk data, where the copy is I/O-bound):
Version
Median time
cp -r (coreutils)
1312 ms
KIO 6.28.0
1997 ms
KIO 6.29-dev (master)
1687 ms
KIO 6.29-dev + batch-copy
1506 ms
KIO 6.29-dev + batch-copy-stat
1454 ms
The small-files case is the story. KIO 6.28 was about 20x slower than cp, which is exactly the ratio the 2014 report complained about. Removing the socket for in-process workers, together with no longer probing the destination filesystem once per file, takes it from about 1.6 s to 0.4 s (roughly 4x). Batching the copy takes it to 88 ms, essentially cp speed and about 18x faster than 6.28. That "I use cp instead of dolphin" line finally has an answer.
The large-file case was already well covered before any of this work, and the table shows it: the copy is bound by moving the bytes, so even KIO 6.28 stayed close to cp there, and the per-file optimizations barely move the number (batch-copy lands within about 15% of cp). That is the whole reason this effort targets many small files instead, where the fixed per-file cost, not the data, is what dominates.
batch-copy and batch-copy-stat come out tied here: the benchmark copies a single directory, so its entries arrive in one listing and batch-stat has nothing to batch. It helps the other case, copying a large selection of individual files that would otherwise be one stat round-trip each. Since it removes the round-trip and not the stat call, the win is largest when stats are cheap, not when the disk is slow. Read the two as equal on this test.
And cp will almost certainly stay a little ahead, by design: KIO does more than copy the bytes. It reports per-file progress, can be paused and cancelled, keeps an undo record, preserves permissions and timestamps, resolves conflicts, and tells any open file manager what changed so its view refreshes. That work is not free, and the goal was never to beat cp, only to make the local case fast enough that reaching for cp instead of Dolphin stops being the obvious choice.
Caveats and what is next
These are laptop numbers on one ext4 disk with warm caches, meant to compare versions, not to be absolute. On Btrfs or XFS the batch path reflinks instead of copying, which changes the large-file picture entirely. The batch fast path only engages for plain local-to-local copies on a responsive filesystem; anything else (network, FAT/NTFS, conflicts needing a dialog) falls back to the existing per-file path, unchanged.
Thanks to David Faure for the in-process worker threads that made all of this possible, to Frank Reininghaus for the earlier listing fixes, and to Alexander Nestorov for a bug report that aged well enough to still be worth closing.
Months ago, some distributions accidentally removed cryfs and encfs from Vaults dependencies (temporarily). And some distributions are removing them intentionally from their package repositories (at least, for the time being).
It might be a good idea to switch your vaults to gocrtyptfs.
There is no automatic process for this, just create a new vault (it will be gocryptfs-based - other backends have been removed from the UI in the latest versions) and copy the data from the old one there.
Some context
To avoid users thinking there is something serious going on, this is some background on changes:
Plasma Vault creation wizard supports only gocryptfs since plasma-vault/-/merge_requests/62 as it is the most maintained upstream project, and to avoid "confusing the users".
Some distro packagers thought this means Vault no longer supports cryfs and encfs and they removed them from the package dependencies. This change was quickly reverted as there are existing users that already have cryfs and encfs-based Vaults.
Some distros are cleaning up FUSE2-based file systems and going FUSE3-only. Some of them ship a FUSE3-based CryFS, and some seem to be waiting for an official FUSE3-supporting release (see github.com/cryfs/cryfs/issues/419).
So, nothing important has happened. Your vaults are as safe as they always were.
It is just that it might bring you a headache if the backend you use for your vaults disappeared after you update your system.
And headaches for me when I get bug reports that Vaults no longer support encfs or cryfs :)
