gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

archsoft · 2026-01-26 12:19:23

With upgrading gdk-pixbuf2 (2.42.12-2 => 2.44.1-4) in September 2025 "glycin" was enabled.

Since then I noticed gdk-pixbuf-glycin-tmp.XXXXXX files in the /tmp directory. Opening a gtk program like GIMP created hundreds of new files. The files only appear temporarily and are deleted immediately. However, they can be viewed briefly in the MATE file manager (caja).

Reproduce way one: Open file manager on /tmp first, then open GIMP.

Reproduce way two: Start inotifywait, then open GIMP. (inotifywait can live monitoring filesystem actions)

inotifywait -m -r -e create -e delete --format 'PATH:%w%f EVENTS:%,e' /tmp

output:

PATH:/tmp/gdk-pixbuf-glycin-tmp.TGJUJ3 EVENTS:CREATE
PATH:/tmp/gdk-pixbuf-glycin-tmp.TGJUJ3 EVENTS:DELETE
PATH:/tmp/gdk-pixbuf-glycin-tmp.JV0QJ3 EVENTS:CREATE
PATH:/tmp/gdk-pixbuf-glycin-tmp.JV0QJ3 EVENTS:DELETE
PATH:/tmp/gdk-pixbuf-glycin-tmp.PY1RJ3 EVENTS:CREATE
PATH:/tmp/gdk-pixbuf-glycin-tmp.PY1RJ3 EVENTS:DELETE
PATH:/tmp/gdk-pixbuf-glycin-tmp.F3XRJ3 EVENTS:CREATE
PATH:/tmp/gdk-pixbuf-glycin-tmp.F3XRJ3 EVENTS:DELETE
...

The problem since the update is that my computer has become noticeably slower. This is especially noticeable when using GIMP. For example, when clicking on the menu (File/Edit/View/...), it sometimes takes a second for it to appear. Each click creates new gdk-pixbuf-glycin-tmp.XXXXXX files in the tmp directory.

I looked at the gdk-pixbuf source code and found the function (gdk_pixbuf__glycin_image_begin_load) that creates the files.: https://gitlab.gnome.org/GNOME/gdk-pixb … heads#L560

Now I'm wondering, does everyone have this problem with the slowed-down system?

seth · 2026-01-26 13:28:08

https://aur.archlinux.org/packages?O=0&K=noglycin

Is /tmp not a tmpfs?

lsblk -f

archsoft · 2026-01-26 13:56:13

Thanks for your posting. Yes, my /tmp is tmpfs. I've seen the noglycine packages before, but that can't be the solution. Or rather, I wanted to know if there are other people who have noticed a slowdown...

seth · 2026-01-26 14:03:47

I'm not sure why you'd experience a significant slowdown on tmpfs file creation - is the RAM encrypted?

but that can't be the solution

The solution is to migrate your software stack away from pixbuf. Upstream seems dead set on that nonsense.

archsoft · 2026-01-26 18:32:22

How do I get away from pixbuf? As I understand it, isn't that part of GTK?

My RAM isn't encrypted. I don't think the /tmp directory is the problem. What might be unusual is that the files are being recreated repeatedly. I made a animated GIF of a screenrecord to illustrate this.

Are all these files being recreated for other users as well? Perhaps my cache is corrupted somewhere, causing the files to be recreated repeatedly.

(Click to see the animated GIF)

seth · 2026-01-26 20:27:07

As I understand it, isn't that part of GTK?

More or less, yes.

What might be unusual is that the files are being recreated repeatedly.

The behavior is inherent to glycin, what is a bit weird is all the images apparently opened when toggling a menu.
I straced gimp for openat and just opening the help menu loads some icons but not for most other menus and the icon is also kept in gimps memory (so not loaded from disk again)
There've been issues reported about glycin that were related to pango (which irritatingly is the font system), so that might be at play here, https://gitlab.gnome.org/GNOME/glycin/-/issues/196

About the tmpfs overhead:

mkdir /tmp/foo
cd /tmp/foo
time bash -c 'for ((i=0;i<100;++i)); do dd if=/dev/zero of=$i count=1 status=none; done'

archsoft · 2026-01-26 22:56:58

Thanks for your time.

I use the "vimix-gtk-themes". I just discovered by chance that the problem doesn't exist when I use an original MATE theme. Then, when using GIMP, a few glycin-files are only created once while clicking in menu. And the application feels lot of faster.

So the problem is not the /tmp directory, but the continuous creation of the files. I haven't been able to find out any more at the moment.

bash output:

bash -c   0,04s user 0,06s system 100% cpu 0,106 total

I looked at issue 196, I don't have a ~/.local/share/fonts directory.

seth · 2026-01-26 23:12:24

It's probably all those here constantly re-loaded to render the GUI, https://github.com/vinceliuice/Vimix-gt … gtk/assets and the overhead added by glycin (which is unlikely to be driven by the temporary files but the sandbox setup) doesn't scale with that.

archsoft · 2026-01-27 20:29:15

I've tried other themes, and even some original MATE themes cause the glycin-files to be constantly created. So it's not just Vimix that's affected. I've experimented with strace to try and find the source of the problem. Unfortunately, I'm now stuck.

seth · 2026-01-27 20:36:36

Those files will get created whenever gdk-pixbuf2 loads any image, for whatever reason.
The behavior of that will be down to the specific gtk theme engine in your case ("original MATE" or not)

Since upstream (gnome) considers everything that's not adwaita an insolence, they won't care - you'd have to address the theme engine authors about that behavior.
(tbf, such behavior is pretty inefficient even w/o glycin in the mix)

brumaire · 2026-01-29 11:08:06

archsoft wrote:

Thanks for your posting. Yes, my /tmp is tmpfs. I've seen the noglycine packages before, but that can't be the solution. Or rather, I wanted to know if there are other people who have noticed a slowdown...

I didn't noticed that specific issue, but I well noticed when my already sandboxed apps suddently stopped working, or crashed when opening the file picker because of glycin invoking bbwrap which expected unprivileged userns, which is, IMHO a dangerous feature I don't want anywhere near I store important personal data…

As stated, there is nothing we can do except maybe put pressure on projects to drop gdk-pixbuf2 (and glycin) for alternatives that comply with the diversity of user setups and users security expectations. The fact that big corpo backed software (firefox, code…) still use gdk-pixbuf2 is, imho, quite insane and they should be shamed for relying on obsolete, almost unmaintained stuff instead of investing resources in saner projects.

Last edited by brumaire (2026-01-29 11:09:11)

Arch Linux

#1 2026-01-26 12:19:23

gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#2 2026-01-26 13:28:08

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#3 2026-01-26 13:56:13

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#4 2026-01-26 14:03:47

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#5 2026-01-26 18:32:22

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#6 2026-01-26 20:27:07

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#7 2026-01-26 22:56:58

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#8 2026-01-26 23:12:24

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#9 2026-01-27 20:29:15

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#10 2026-01-27 20:36:36

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

#11 2026-01-29 11:08:06

Re: gdk-pixbuf2: gdk-pixbuf-glycin-tmp.XXXXXX files slows down the system

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