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50+ Segmentation Faults per Hour: Continuing to Stress Ryzen

phoronix.com

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Re: 50+ Segmentation Faults per Hour: Continuing to Stress Ryzen

#41
post #7

Earlier quoted context omitted.

Can we all switch to Xeons and ? Or do those have similar issues?

No idea, but honestly I can't be arsed anymore with new stuff when it's so unreliable. This is from a few minutes ago (the timestamps are hours old, but that's because dmesg timestamps don't take into account sleep time) [Sat Aug 5 13:46:21 2017] ------------[ cut here ]------------ [Sat Aug 5 13:46:21 2017] WARNING: CPU: 0 PID: 16026 at drivers/base/firmware_class.c:1225 _request_firmware+0x51f/0x8a0 [Sat Aug 5 13:4…

That's a warning (~= assert()), not a segfault.

Re: 50+ Segmentation Faults per Hour: Continuing to Stress Ryzen

#43
post #22

I have the same with a Kaby Lake laptop btw (XPS 13) where random segfaults happen. This is with the very latest BIOS update from a day or two ago. Modern CPUs suck.

I wonder if this can also be attributed to the highly-microcoded nature of modern CPUs. (Then, at least, it may be software that sucks, not hardware.)

I'd say it has to do more with the absolutely tiny process feature sizes, where transistors stop behaving like switches and the statistical uncertainties of quantum mechanics start becoming relevant.

Re: 50+ Segmentation Faults per Hour: Continuing to Stress Ryzen

#44
post #22

Earlier quoted context omitted.

I wonder if this can also be attributed to the highly-microcoded nature of modern CPUs. (Then, at least, it may be software that sucks, not hardware.)

I'd say it has to do more with the absolutely tiny process feature sizes, where transistors stop behaving like switches and the statistical uncertainties of quantum mechanics start becoming relevant.

14 nm is still a fairly large size on the molecular scale. Things of this size still behave classically for the most part (that is, ignoring the fact that a transistor, however large, is an essentially quantum-mechanical device to begin with). What might matter at this scale is thermal and capacitance effects.

Re: 50+ Segmentation Faults per Hour: Continuing to Stress Ryzen

#45

Note that it appears that a large number of the segfaults which Michael (phoronix) is reporting may be coming from a software issue. In particular, people on the phoronix forums are reporting that conftest segfaults are a known software issue and also one has reported that he was able to reproduce the conftest segfaults on an intel CPU. So not saying that there's not a problem with Ryzen, but it is possible a large n…

This isn't the case. I see segfaults in multiple tests with Ryzen and none of them are conftest related. The CPU is broken.

I don't have Threadripper or Epyc to test.

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