Dual-GPU support: Launch on the discrete GPU automatically

*reality TV show deep voice guy*

In 2016, we added a way to launch apps on the discrete GPU.

*swoosh effects*

In 2019, we added a way for that to work with the NVidia drivers.

*explosions*

In 2020, we're adding a way for applications to launch automatically on the discrete GPU.

*fast cuts of loads of applications being launched and quiet*

Introducing the (badly-named-but-if-you-can-come-up-with-a-better-name-youre-ready-for-computers) “PrefersNonDefaultGPU” desktop entry key.

From the specifications website:

If true, the application prefers to be run on a more powerful discrete GPU if available, which we describe as “a GPU other than the default one” in this spec to avoid the need to define what a discrete GPU is and in which cases it might be considered more powerful than the default GPU. This key is only a hint and support might not be present depending on the implementation. 

And support for that key is coming to GNOME Shell soon.

TL;DR

Add “PrefersNonDefaultGPU=true” to your application's .desktop file if it can benefit from being run on a more powerful GPU.

We've also added a switcherooctl command to recent versions of switcheroo-control so you can launch your apps on the right GPU from your scripts and tweaks.

Dual-GPU support follow-up: NVIDIA driver support

If you remember, back in 2016, I did the work to get a “Launch on Discrete GPU” menu item added to application in gnome-shell.

This cycle I worked on adding support for the NVIDIA proprietary driver, so that the menu item shows up, and the right environment variables are used to launch applications on that device.

Tested with another unsupported device...

Behind the scenes

There were a number of problems with the old detection code in switcheroo-control:
- it required the graphics card to use vga_switcheroo in the kernel, which the NVIDIA driver didn't do
- it could support more than 2 GPUs
- and it didn't really actually know which GPU was going to be the “main” one

And, on top of all that, gnome-shell expected the Mesa OpenGL stack to be used, so it only knew the right environment variables to do that, and only for one secondary GPU.

So we've extended switcheroo-control and its API to do all this.

(As a side note, commenters asked me about the KDE support, and how it would integrate, and it turns out that KDE's code just checks for the presence of a file in /sys, which is only present when vga_switcheroo is used. So I would encourage KDE to adopt the switcheroo-control D-Bus API for this)

Closing

All this will be available in Fedora 32, using GNOME 3.36 and switcheroo-control 2.0. We might backport this to Fedora 31 after it's been tested, and if there is enough interest.

Dual-GPU integration in GNOME

Thanks to the work of Hans de Goede and many others, dual-GPU (aka NVidia Optimus or AMD Hybrid Graphics) support works better than ever in Fedora 25.

On my side, I picked up some work I originally did for Fedora 24, but ended up being blocked by hardware support. This brings better integration into GNOME.

The Details Settings panel now shows which video cards you have in your (most likely) laptop.

dual-GPU Graphics

The second feature is what Blender and 3D video games users have been waiting for: a contextual menu item to launch the application on the more powerful GPU in your machine.

Mooo Powaa!

This demonstration uses a slightly modified GtkGLArea example, which shows which of the GPUs is used to render the application in the title bar.

on the integrated GPU

on the discrete GPU

Behind the curtain

Behind those 2 features, we have a simple D-Bus service, which runs automatically on boot, and stays running to offer a single property (HasDualGpu) that system components can use to detect what UI to present. This requires the "switcheroo" driver to work on the machine in question.

Because of the way applications are launched on the discrete GPU, we cannot currently support D-Bus activated applications, but GPU-heavy D-Bus-integrated applications are few and far between right now.

Future plans

There's plenty more to do in this area, to polish the integration. We might want applications to tell us whether they'd prefer being run on the integrated or discrete GPU, as live switching between renderers is still something that's out of the question on Linux.

Wayland dual-GPU support, as well as support for the proprietary NVidia drivers are also things that will be worked on, probably by my colleagues though, as the graphics stack really isn't my field.

And if the hardware becomes more widely available, we'll most certainly want to support hardware with hotpluggable graphics support (whether gaming laptop "power-ups" or workstation docks).

Availability

All the patches necessary to make this work are now available in GNOME git (targeted at GNOME 3.24), and backports are integrated in Fedora 25, due to be released shortly.

GNOME 3.18, here we go

As I'm known to do, a focus on the little things I worked on during the just released GNOME 3.18 development cycle.

Hardware support

The accelerometer support in GNOME now uses iio-sensor-proxy. This daemon also now supports ambient light sensors, which Richard used to implement the automatic brightness adjustment, and compasses, which are used in GeoClue and gnome-maps.

In kernel-land, I've fixed the detection of some Bosch accelerometers, added support for another Kyonix one, as used in some tablets.

I've also added quirks for out-of-the-box touchscreen support on some cheaper tablets using the goodix driver, and started reviewing a number of patches for that same touchscreen.

With Larry Finger, of Realtek kernel drivers fame, we've carried on cleaning up the Realtek 8723BS driver used in the majority of Windows-compatible tablets, in the Endless computer, and even in the $9 C.H.I.P. Linux computer.

Bluetooth UI changes

The Bluetooth panel now has better « empty states », explaining how to get Bluetooth working again when a hardware killswitch is used, or it's been turned off by hand. We've also made receiving files through OBEX Push easier, and builtin to the Bluetooth panel, so that you won't forget to turn it off when done, and won't have trouble finding it, as is the case for settings that aren't used often.

Videos

GNOME Videos has seen some work, mostly in the stabilisation, and bug fixing department, most of those fixes were also landed in the 3.16 version.

We've also been laying the groundwork in grilo for writing ever less code in C for plugin sources. Grilo Lua plugins can now use gnome-online-accounts to access keys for specific accounts, which we've used to re-implement the Pocket videos plugin, as well as the Last.fm cover art plugin.

All those changes should allow implementing OwnCloud support in gnome-music in GNOME 3.20.

My favourite GNOME 3.18 features

You can call them features, or bug fixes, but the overall improvements in the Wayland and touchpad/touchscreen support are pretty exciting. Do try it out when you get a GNOME 3.18 installation, and file bugs, it's coming soon!

Talking of bug fixes, this one means that I don't need to put in my password by hand when I want to access work related resources. Connect to the VPN, and I'm authenticated to Kerberos.

I've also got a particular attachment to the GeoClue GPS support through phones. This allows us to have more accurate geolocation support than any desktop environments around.

A few for later

The LibreOfficeKit support that will be coming to gnome-documents will help us get support for EPubs in gnome-books, as it will make it easier to plug in previewers other than the Evince widget.

Victor Toso has also been working through my Grilo bugs to allow us to implement a preview page when opening videos. Work has already started on that, so fingers crossed for GNOME 3.20!

Fresh software from the 3.14 menu

Here is a small recap of the GNOME 3.14 features I worked on. Some are already well publicised, through blogs:

• Brought maturity to GOM. It's now usable for real applications (including a number of grilo plugins), and will be gaining features for the more demanding uses soon (such as batched writes), along with gjs support.
• Made the default firewall experience on Fedora better (and made Sharing better on every NetworkManager-using Linux distribution, by the same token).
• Automatic rotation for Windows 8 certified devices. This will still need more work to be integrated into systemd/udev or GNOME.
• Worked on architecturing the Sharing functionality between applications which will be required for sandboxed applications.
• A bit last minute, but Totem now works on Wayland, triggering more bugs in the stack.

And obviously loads of bug fixes, and patch reviews. And I do mean loads :)

To look forward to

If all goes according to plan, I'll be able to merge the aforementioned automatic rotation support into systemd/udev. The kernel API is pretty bad, which makes the user-space code look bad...

The first parts of ebooks support in gnome-documents have already been written, scheduled for 3.16.

And my favourites

Note: With links that will open up like a Christmas present when GNOME 3.14 is released.

There are a lot of big, new features in GNOME 3.14. The Adwaita rewrite made it possible to polish the theme greatly. The captive portals support is very useful, the travelling you will enjoy this (I certainly have!).

But my favourite new feature has to be the gestures support in gnome-shell. I'll make good use of that :)

A follow up to yesterday's Videos new for 3.14

The more astute (or Wayland testing) amongst you will recognise mutter running a nested Wayland compositor. Yes, it means that Videos will work natively under Wayland.

Got to love indie films

It's not perfect, as I'm still seeing hangs within the Intel driver for a number of operations, but basic playback works, and the playback is actually within the same window and correctly hidden when in the overview ;)

GNOME 3.10 is coming!

The new release is coming! As has been the case for the past couple of releases, I've mostly been shepherding great work by other contributors, and I'll detail my limited contributions beyond mere bug fixing.

Wayland support

I've done some work on enabling clutter-gtk applications to be able to run on  Wayland though the harder work of implementing sub-surfaces is still pending.

Giovanni has done incredible work on mutter to start moving some of the X11 dependent code inside the compositor, which should allow you to run a (cut down) Wayland session using gnome-shell.

This also means that Thomas Wood's redesigned Displays panel has Wayland support. A perfect storm of changes for one of the only panels that received little attention since the GNOME 2.x days.

The new displays panel with a TV that claims to be oh so small

Date & Time redesign

Zeeshan, through his work on Geoclue2, and Kalev, through his Summer of Code project, have completely redesigned the Date & Time panel. Aside from being easier to setup, it means that we can finally implement the automatic timezone switching depending on your location.

The new Date & Time panel

BlueZ 5 support

GNOME is the first major desktop to ship with BlueZ 5 support, thanks to work by Gustavo Padovan and Emilio Pozuelo Monfort.

The older version was not supported anymore, and the new version allows us to support things like "Just Works" pairing, better support of audio devices (though the PulseAudio 5.x release to support this is only coming shortly after GNOME 3.10) and a much better architecture for a more stable operation.

GNOME 3.12 should see a redesigned Bluetooth panel, to match current best practices on other platforms (such as merging the management and pairing wizard UIs into one).

Bluetooth devices in use

Miscellaneous

Intuos 4 OLEDs

OLED support for Wacom Intuos 4 tablets (as seen above, thanks Przemo), media keys support for MPRIS applications such as Spotify (thanks to Michael Wood and Lars Uebernickel), updated UI for the Universal Access panel (the ever present Matthias Clasen), support for many more fingerprint readers in libfprint (thanks Vasily Khoruzhick).

Redesigned Universal Access panel

And to my contributions

More work on Videos. Totem 3.10 is still based on the same interface as in GNOME 3.8, but some work has been on the master branch towards the new UI, with some of the features getting backported. We have:

• new session management for when Totem crashes
• support for chapters within files (such as Matroska videos)
• Wayland bug fixes in GTK+, clutter and the combined clutter-gtk
• a completed GDBus port
• Working overlaid controls (though their behaviour isn't quite up to scratch)
• Remote files support in Grilo, including support for Recent files
• Started work on merging the various sidebars within the main view (which included landing GtkSearchBar in GTK+)
• libquvi 0.9 support

On top of which you'll find the usual mix of bug fixes, small features, itch scratching, and swamp-draining in finger-pointing fests.

I also spent quite a bit of time on a side project that didn't come to fruition at this time, but I hope to be able to post some details soon.