Ubuntu LTS version? about ryzen-test

[Daniel451]

EDIT: Forget about this. 17.04 and older does not boot with my R7 2700X / GTX 1080 / X470 mainboard, not even in terminal.

Can I just replace gcc7 with gcc8.1 for the build loop? This has already fixed the glibc stuff.

Or any other ideas how to solve that issue?

[m-r-s]

Probably you can replace gcc7 with gcc8.1...

However, we do not know if this combination of code, compiler and libraries will lead to the problematic command chain which triggers the bug.
No one can guarantee that changing anything from the confirmed combination (stock Ubuntu 17.04. with gcc7) will be suitable or reliable to test for the the unexpected behavior.

There is no solution to this problem apart from finding another reliable way to trigger the bug, which requires hours of testing and many people with defective CPUs to confirm that is actually works.

[Daniel451]

True. This is kind of problematic I guess...without applying newer kernels, for example, a R7 2700X CPU does not seem to properly work with Ubuntu 17.04 or older, thus one either has to do apply significant changes to Ubuntu 17.04 in order to get this running with Ryzen 2000 series CPUs or use some gcc configuration that differs to the one tested with this repository in order to get around the glibc change.

I'll test gcc8.1 now and report again. So far I did not encounter segfaults, but the 2700X + X470 mainboard is only 1 week old now...not much time to compile software yet.

[suaefar]

We don't have any "positive" reports from Ryzen 2XXX CPUs, yet.
I can only hope (for AMD, the sake of competition, and us all) that you won't find this behavior in the second generation of Ryzen CPUs.

With the old/early Ryzen CPUs there were several ways to trigger the bug, mainly by compiling stuff in parallel. I just published this script as a reference, as it turned out to be very effective.

Just keep an eye on the output of dmesg when you are doing CPU and MEM-intensive stuff.
If you see strange segfaults that do not appear on other CPUs, you have an indicator where to start.

[Daniel451]

Ok, thanks for the reply!

So far I have compiled TensorFlow, OpenCV, ROS, GCC 8.1, and some own stuff without issues.

ryzen-kill.sh ran for nearly 5 hours now with GCC 8.1 and no issues yet.

[EdgarMCR]

I just managed to freeze a AMD Threadripper 2950X system with this test on Ubuntu 18.04 LTS

I do not get any error messages, just that the whole system freezes and only a hard reset will get it to reboot.

Thank you very much, I found it difficult to reproduce the failure before I found your test!

Edit: I was running this on an ASUS® PRIME X399-A motherboard with bios version 0807. I noticed that bios version 0808 was released on the 17th October and updating the bios resolved my issue.