Gentoo Image, Which Applications are in and Which are Out

Not real pressing news but we wanted qtpyvcp built and ready to go since we use it to build custom GUI's.

LXQt is most likely going to be pulled out in the next release as I'm currently having major problems with it. XFCE 4.20 pre-release is actually quite stable though so that's a no-brainer

edit: LXQt problem is fixed for now, will be included in the image.

The mainline 6.12 kernel has the i915 DRM (Direct Rendering Manager) driver has been disabled if PREEMPT_RT is selected in Kconfig. I guess the fixes for the i915 driver that were in the PREEMPT_RT kernel patch have not made it into mainline, so the driver has been forcibly disabled for now. The newer Intel Xe driver on the other hand is perfectly fine. Hardware acceleration will not work on Intel GPUs that are not covered by the Xe driver. When i915 has been re-enabled, I will push a new Gentoo image with the driver on.

git.kernel.org/pub/scm/linux/kernel/git/...Kconfig?h=v6.12.1#n6

config DRM_I915 depends on !PREEMPT_RT

I have however set the Xe Intel driver force_probe feature to "*" which enables the Xe driver for all known devices.

www.phoronix.com/review/intel-xe-benchmark

"This driver is designed just to support Intel Tigerlake Gen12 graphics and newer -- both integrated and discrete graphics moving forward. "

Also, this will _not_ be the case in the kernel I built:

"With the Xe DRM driver in Linux 6.8, the driver remains disabled by default for all released Intel integrated and discrete graphics hardware. Even when building the Intel Xe driver to be part of the kernel, it will be off by default with the long-used i815 kernel driver remaining the default. But it is easy to switch to this new driver when the Xe driver is included. Via boot parameters like "i915.force_probe=!56a2 xe.force_probe=56a2" is enough to prevent loading of the i915 driver and loading instead the experimental Xe driver, assuming your PCI graphics ID is 0x56a2. Just adjust for your appropriate Intel PCI graphics ID and from there it's easy to boot with this new kernel driver."

You will not have to specify IDs in the kernel command line in order to use the Xe driver as this has been enabled already in Kconfig.

Sorry for the inconvenience, I know a lot of you may be running older i915 hardware. I'm going to test this on an Intel laptop to make sure X at least works with the proper display resolution, but hardware 3D acceleration may not work for some of you.

edit: Just cloned the linux-rt-devel git repository, switched to the 6.12.y-rt branch, pulled in the 6.12.y branch from stable to update it, so the i915 driver has been re-enabled. 6.12.1 with i915 is a go! The PREEMPT_RT kernel patch series hasn't been updated since 6.12-rc4, so that's fixed.

edit 2: The 6.12 mainline kernel, while has PREEMPT_RT enabled, is actually a bit useless because real-time applications check for /sys/kernel/realtime including LinuxCNC. This patch is required for LinuxCNC to work with real-time POSIX threads:

git.kernel.org/pub/scm/linux/kernel/git/...be0b95341fdc7ef1c193

So I'll be maintaining my own 6.12 real-time kernel repository that also allows building with the -O3 flag.

All is well!

Deleted... Oops didn't read carefully

The kernel is up! 6.12.1 fully patched with the entire PREEMPT_RT patch set, so i915 is back online:

github.com/NTULINUX/linux

-O3 is good to go as well.

edit: New kernel repo:

github.com/NTULINUX/linux/tree/ntulinux/linux-6.12.y-rt

Don't you think that i915 is kept out of the realtime kernel for a reason?
Never mind,  I see you applied the previous patched, good job

My posts here can be deleted to keep it a bit more clean