[isabelle-dev] [158c513a39f5] JVM crash

[Manuel Eberl]

Addendum: I did a system upgrade (including a major kernel upgrade)
around the same time when I first noticed the problem and I don't think
I rebooted afterwards, so one very plausible explanation is that Linux
introduced some workarounds/bug fixes in the kernel within the last few
weeks that solved whatever issue I was having, and, of course, it took a
reboot for it to kick in.

On 20/08/17 14:14, Manuel Eberl wrote:
> Okay I have no idea what is going on anymore.
> 
> I know have the following new data points:
> – 2500 iterations on my Intel Core i7 laptop. No failures.
> 
> So it must be the Ryzen issue after all, I thought. I recalled that some
> people said the problem was less pronounced with SMT disabled, so I
> disabled it.
> – 100 iterations on Ryzen 1800X after a reboot with SMT disabled. No
> failures.
> – 100 iterations on Ryzen 1800X after another reboot with SMT enabled
> again. No failures.
> 
> So it seems the problem went away as mysteriously as it appeared and it
> probably has something to do with the hardware or software constellation
> on my computer. Or perhaps I should check my flat for radiation sources.
> 
> Cheers,
> 
> Manuel
> 
> 
> On 20/08/17 11:24, Lars Hupel wrote:
>>> Lars, maybe you can run the same test on your machine and see what
>>> happens there.
>>
>> I did, and nothing happened for about 100 iterations. I have a Core
>> i7-2600. OS is otherwise identical to Manuel (Arch Linux).
>>
>>> As for Scala, could a problem in the Scala compiler really lead to the
>>> JVM segfaulting? I would have thought if the JVM segfaults, that's a bug
>>> in the JVM. (unless it's a hardware-related issue, of course)
>>
>> I've seen it happening, but it is very rare. Still, the coincidence of
>> crashes during compilation could be explained by random chance (even if
>> very unlikely). A quick look over Scala's issue tracker reveals no
>> documented JVM segfaults after 2011.
>>
>> Cheers
>> Lars
>>