Raptor Computing Systems Community Forums (BETA)

Water Cooler => General OpenPOWER Discussion => Topic started by: pocock on December 29, 2020, 11:08:08 am

Title: risks associated with Xorg / Wayland
Post by: pocock on December 29, 2020, 11:08:08 am
There is regular noise about Linux distributions being on the cusp of abandoning Xorg, e.g. the recent Phoronix article about Xorg being abandonware (https://www.phoronix.com/scan.php?page=news_item&px=XServer-Abandonware), which generated many blogs and comments on various platforms (https://duckduckgo.com/?q=xorg+abandonware&t=ffab&ia=web).

Talos II and Blackbird users have commented that Wayland isn't working for us.  I personally use Xorg right now, I have this in my /etc/gdm3/daemon.conf

Code: [Select]
[daemon]
# Uncomment the line below to force the login screen to use Xorg
WaylandEnable=false


Has anybody investigated the Wayland issues on this architecture in any depth?

I don't see any distribution dropping Xorg in the next 12 months but as these machines have a long lifespan, if Xorg is dropped in 2 or 3 years from now then it will be an inconvenience for this platform.
Title: Re: risks associated with Xorg / Wayland
Post by: ClassicHasClass on December 29, 2020, 03:58:42 pm
Wayland works "fine" (for various values of "fine") if you have a GPU. Or I should say, my objections to Wayland remain the same on my T2 as they do on x86_64.

My BMC-only Blackbird ran like glue with Wayland, and this was acknowledged (for various values of "acknowledged") by a Wayland developer I consulted with about it. This did seem to improve in Fedora 33, possibly due to other improvements such as in llvmpipe, but it can't be tricked into generating any larger displays so far: https://www.talospace.com/2020/11/fedora-33-mini-review-on-blackbird-and.html

I should also note I am no longer running gdm at all. I boot to a text prompt and start Xorg or Wayland manually. This also solved a lot of problems.
Title: Re: risks associated with Xorg / Wayland
Post by: pocock on December 29, 2020, 05:08:15 pm
These are positive signs and I suspect there will be enough time to improve these things more before Xorg ever gets dropped by any distributions.

Personally, I found that the display wouldn't work for me with Wayland enabled in gdm.  I'm using an AMD GPU, the RX 580 and it has been very stable with Xorg.

For more widespread adoption of the platform, which will give it more critical mass, not everybody will want to go through a text prompt.  This type of hack is fine for some of us and helps prove what can and will work eventually though.
Title: Re: risks associated with Xorg / Wayland
Post by: ClassicHasClass on December 30, 2020, 12:59:06 am
Yes, I'm certainly prepared to admit that gdm is part of the problem. A lot of things worked better without it.
Title: Re: risks associated with Xorg / Wayland
Post by: Borley on January 03, 2021, 10:56:34 am
I have been running Wayland on my Blackbird since the day I got it. There are issues, but nothing that is unique to POWER. In order to record the screen, I have to log out into an Xorg session. While Synaptic and GUFW do not run under Wayland without some modifications for which I have written guides (https://unix.stackexchange.com/questions/594183/how-to-run-graphical-applications-as-root-under-wayland).
Title: Re: risks associated with Xorg / Wayland
Post by: pocock on January 03, 2021, 11:09:46 am
Actually, I'm hoping that some of the issues will disappear if people use the kernels produced with a regular 4k page size (https://forums.raptorcs.com/index.php/topic,247.0.html)

Problems rooted in the 64k page size are not problems with the ppc64 platform.  Now people have both the information and the choice (https://forums.raptorcs.com/index.php/topic,247.0.html) to use 4k like other architectures.  If a particular fault occurs with 64k and not with 4k, then it is a Wayland fault or something in the drivers.  Nonetheless, the vast majority of users will probably want to use the 4k page size rather than waiting for everybody else to support 64k.

Beyond that, I'm also hoping that Wayland developers will take feedback from users on every platform.

Based on my experience with the way systemd was imposed on the world, speaking as a developer, a sysadmin and a user, I feel that we were used as guinea pigs and I feel we may go through a similar experience with Wayland.  On Debian jessie, the first Debian release to use systemd by default, I encountered a range of issues.  Even today, on systems upgraded to the latest Debian, I still find issues that can be traced back to the introduction of systemd.