[Solved - no bug] RPi5 slower than RPi 4 Bug?

[denk]

Hi,

I am using RPIs as my home lab server since years. At the end of last year I switched from the RPi4 8GB to a RPi5 8GB. I use the same USB SSD with the same data on the RPi5, which ran for years on the RPi4. I am using linux-rpi - I cannot use linux-rpi-16k, as I run software, which is not compatible with a page size of 16k. Everything is working except one weird issue. Since I moved to the RPi5, docker compose commands like docker compose pull can take over 1000 seconds for bigger images. This was not the case when I was using the RPi4, there the maximum was around 250 seconds. When I run glances during docker compose pull, I can see that iowait is around 20-25% most of the time, at max over 50%.
I already cloned the ssd to a new one, didn't change anything. Now I cloned it to an NVME ssd and connected this SSD directly to PCIE with a Geekworm X1003, didn't change anything.
I have no clue, what might be going wrong here. Does anybody have similar issues? What could I do to fix that? Any ideas, where I could start investigating?
If I can provide further info, please ask.

[b]Update:[/b]
Actually there seems to be no general performance problem with RPi5. I stumbled upon a bug in ext4, which lead to my performance problems: [url]https://bugzilla.kernel.org/show_bug.cgi?id=217965[/url]
I don't know why, but my ssd had stripe=8191 set in its options, which leads to the described heavy performance regression. Setting it to 0 as described in the bug report fixed it for me. With kernels 6.8+ the underlying issue should be solved. So in my case the coincidence was, that I did two things at the same time: when I switched from my RPi4 to the RPi5, I also updated the system from 6.1.x to kernel 6.6.x, where the performance regression appeared. Marking this as solved.