In the last few days I have been working with PDF files again. I noticed that the PDF reader I use, Zathura, takes a surprisingly long pause of 2-3 seconds the first time I start it. However, this behavior only occurred the first time I started the application.

So I started to analyze the problem. I used the strace tool, which promptly gave me valid answers.

On the picture you can see that Zathura tries to request something from the nvidia card. And right there it takes about 2 seconds until the process is completed (line 10 close =0)

This information narrowed down the error considerably. So it's not the application's fault, but the application wants to do something with the graphics card. What do such applications do today? They use hardware acceleration to render the content.

the fix

I have been able to work out a workaround for Zathura. Zathura can be made not to use the hardware acceleration with the help of an environment variable. The variable GSK_RENDERER=cairo takes care of this. Strictly speaking, it is the GTK engine that gets the information to render purely software-based.

i added a alias in my .zshrc

alias zathura="GSK_RENDERER=cairo zathura"

After that I could no longer notice any loading delay with Zathura

some notes

useful commands for analyses:

watch cat /proc/driver/nvidia/gpus/0000:01:00.0/power
cat /proc/driver/nvidia/params
echo off | sudo tee /sys/bus/pci/devices/0000:01:00.0/power/control
cat /usr/share/glvnd/egl_vendor.d/*.json