Re: Cuirass instability on aarch64 systems

[Roman Scherer]

Hi,

thank you for your answer. I will try out your suggestion soon.

Roman

On Sun, Jan 21, 2024, 17:47 <guix@ikherbers.com> wrote:

> Hi,
>
> TL;DR: To mitigate this, add `GUILE_JIT_THRESHOLD=-1' as an environment
> variable for Cuirass. If you use the cuirass package from the guix
> channel you should be able to use `package-with-patches' and the
> attached patch.
>
> On 2024-01-21T16:16:57+0100, Roman Scherer wrote:
> >
> > Hi Guix,
> >
> > I'm running Cuirass for one of my channels on an aarch64 VM on the
> Hetzner
> > Cloud. When I visit the Cuirass web interface it sometimes serves the
> page,
> > but most of the time it just serves a blank page.
>
> I have been tracking down the exact same error last week.
>
> My debbuging showed that a related issue has been reported to
> guile-fibers in [0]. There, Andy Wingo suggested that it might be bad
> codegen for atomics[1]. I tried the test case in [0] for guile commits
> 33e07fc56c18d4f3ffbfd53c4a8300bb2b5e49ba which should be the first
> commit to be using the atomic instructions and it failed while it
> succeeded with the previous commit. I also tried applying only part of
> 33e07fc56c18d4f3ffbfd53c4a8300bb2b5e49ba and found that applying the
> changes for `compile_atomic_scm_swap_immediate' also makes the test
> fail. Unfortunately, I'm not proficient in assembly, atomics and JIT and
> don't see anything wrong with it. Even worse, I definitely should be
> doing other things right now :D and haven't had time to report my
> findings. Feel free to do so :). Else, I might find some time next week.
>
> > [...]
> > Recently I submitted this patch [2] to guile-fibers to get my system
> > updated. There were no substitutes available and I had to build the
> package on
> > my server. Unfortuntly that build never completed it just hang in the
> tests.
>
> I too had that problem and was able to work around it by building it on
> my x86_64 laptop using transparent emulation. I don't know if this is
> related and haven't tested it with `GUILE_JIT_THRESHOLD=-1'.
>
> I hope this helps
>
> vicvbcun
>
> [0]: https://github.com/wingo/fibers/issues/83
> [1]: https://github.com/wingo/fibers/issues/83#issuecomment-1538427808
>