On 08.09.2025 19:12, Jakub Ružička wrote:
#> time apt install texlive-latex-extra... Building format(s) --all. This may take some time... done. real 165m27.254s user 164m32.000s sys 0m9.948s
Which qemu version do you use for this test? I bet it is not the one in trixie. We had stronger default pauth implementation in qemu before, which had a similar impact. The default one in qemu in trixie should be much faster - there, the impact should be what I'm seeing (about 2x the difference). With older qemu with stronger pauth impl by default, 10x the difference is also expected. Please try with trixie's qemu-user (you can install qemu-user package form trixie on an older system since this package is self-contained). Now, please disable pauth entirely *in the guest* (in the chroot). For this, the simplest way is to export QEMU_CPU=max,pauth=off so that all processes running within your chroot inherits it. I can't say how to do this in pbuilder though. For a manual test like the above, you can set this variable when running apt command: # export QEMU_CPU=max,pauth=off # time apt install ... If I got it correctly, pauth is the one which started to being used much more aggressively in trixie, and which has large impact on the performance. Please verify if my observations are correct. What we should do next is a different question, and it's not an easy one. Thanks, /mjt
