Fedora 40 mini-review on the Blackbird and Talos II (and a taste of Chromium)

This is Chromium running on GNOME in Xorg in Fedora 40 on the Talos II. I think it says it all, really.

Now, I won't mince words here: I don't like Chromium on philosophical grounds and you shouldn't expect me to be complimentary. But I salute the work that went into making it run. I'll have more to say about that later.

Meanwhile, it's that time again: in the same way I preface all these mini-reviews, Fedora was one of the first mainstream distributions to support POWER9 out of the box, it's still one of the top distributions OpenPOWER denizens use and its position closest to the bleeding, ragged edge is where we see problems emerge first and get fixed (hopefully) before they move further downstream. That's why it's worth caring about it even if you yourself don't run it. Also, as always, recall both my T2 and Blackbird are configured to come up in a text boot instead of gdm and I start the GUI manually from there. I always recommend a non-graphical boot as a recovery mechanism in case your graphics card gets whacked by something or other, and on Fedora this is easily done by ensuring the symlink /etc/systemd/system/default.target points to /lib/systemd/system/multi-user.target.

F40 is the first release since the 2.10 Petitboot PNOR firmware update and I had high hopes that it would fix the problem with stuck XFS logs sometimes making it puke, since it leapfrogs to a much more recent kernel. Both my GPU-less 4-core Blackbird and WX7100 dual-8 Talos II were already upgraded to the current PNOR before beginning and I recommend you do the same. Don't forget to save a copy of your BOOTKERNFW flash partition if your GPU requires it since this operation will erase it (you can flash it back when it's done).

dnf still!!!!! doesn't update grub's config (bug 1921479, showing messages like 0ed84c0-p94177c1: integer expression expected during the process), so the process remains largely unchanged from F38 and F39:

dnf upgrade --refresh # upgrade prior system and DNF
grub2-mkconfig -o /boot/grub2/grub.cfg # force grub to update
dnf install dnf-plugin-system-upgrade # install upgrade plugin if not already done
dnf system-upgrade download --refresh --releasever=40 # download F40 packages
dnf system-upgrade reboot # reboot into upgrader

I always do the Blackbird first as a checkpoint, and got this:

I'm not sure what the issue was, since the Blackbird mostly runs Workstation with only a few extra packages. This didn't happen on the T2. However, I crossed my fingers with --allowerasing and I was able to get it to download on the Blackbird and install.

I also should note that there was no installation screen on either the Blackbird or T2 this time around; for both systems I needed to log in as root on an alternate VTY (Ctrl-Alt-F2 or as appropriate) and dnf system-upgrade log --number=-1 intermittently to watch the updates. You can probably also still monitor it on the virtual TTY in the BMC web interface. Both systems then rebooted (fast reboot is disabled on both) and came up clean, so no XFS burp on the T2! One more grub2-mkconfig -o /boot/grub2/grub.cfg was needed to get Petitboot's menu looking right and the install was complete. I do note with approval that Fedora's boot from Petitboot to prompt was very quick this time around. Good work there.

Now, that desktop environment. I migrated to KDE from GNOME a few releases back after GNOME started messing with my themes, but KDE Plasma 6 in F40 is now Wayland-only; startplasma-x11 doesn't even exist. There is apparently an unofficial package to restore the X11 session but I haven't tried this yet due to a bigger problem I'll get to momentarily. On the GPU-less Blackbird this is a problem because Wayland remains limited to 1024x768 over the built-in HDMI output (Xorg can be coerced up to 1920x1200 with a modeline), so if you've decided to give up and embrace the KDE Wayland Wasteland, you either get to compute like it's 1999 or you get a GPU.

GNOME, on the other hand, does still work in Xorg and performs well on both the Blackbird and T2. Set your .xinitrc to

export XDG_SESSION_TYPE=x11
/usr/bin/gnome-session

and then the usual startx will bring it up from a text boot. Which brings us to this screenshot again:

Chromium is now officially available for the first time on ppc64le as a Fedora package. However, in Xorg it has many visual glitches, and this is true whether or not you have a GPU (this was taken on the Talos II, which has the Raptor BTO WX7100 workstation card).

The reason I entertained running it under Xorg at all was Plasma 6 pretty much broke my custom theme completely and a lot of my applets, even though its Wayland compositor runs fine on the Talos II. (Start it from the text prompt simply with startplasma-wayland.) But the application appears normally.

There are many problems with Chromium on ppc64le (big endian need not apply) and I suspect the major reason is because its JIT appears unfinished. In particular, it seems like most Wasm and certain other operations will make it trap, and as such it's not yet ready for prime time. I'm sure it will continue to improve and the porters are to be congratulated for their hard work on it, but I'll still be trying to get all the pieces in Firefox to go in the same direction, and once the next ESR (128) starts hitting the beta channel we'll at least have Baseline JIT acceleration available for it while I continue to struggle with Ion and Wasm.

Before that, though, I'm deciding what to do, whether to go back to GNOME or try to piece together my custom theme again in KDE. It'll need a fair bit of work. I guess this means it wasn't a good upgrade, though not because it doesn't work on OpenPOWER; it just wasn't a good upgrade, period. I certainly hope the churn will be less in F41.