Re: [regression] oops on heavy compilations ("kernel BUG at mm/zswap.c:1005!" and "Oops: invalid opcode: 0000")

[Nhat Pham <nphamcs@gmail.com>]

On Fri, Aug 23, 2024 at 1:24 PM Piotr Oniszczuk
<piotr.oniszczuk@gmail.com> wrote:
>
>
>
> > Wiadomość napisana przez Nhat Pham <nphamcs@gmail.com> w dniu 23.08.2024, o godz. 18:16:
> >
> > Have you tried with 6.9 yet? IIRC, there are two major changes to
> > zswap architecture in recent versions.
>
> No. But now building vanilla 6.9.12. Will install and see…
> (This will take some time as catching issue needs days of compilation)
>
> >
> > 1. In 6.9, we range-partition zswap's rbtrees to reduce lock contention.
> >
> > 2. In 6.10, we replace zswap's rbtrees with xarrays.
> >
> > If 6.9 is fine, then the latter is the suspect, and vice versa. Of
> > course, the minor changes are still suspect - but you get the idea :)
> >
> >>
> >> btw: we can go with elimination strategy.
> >> So what i need to change/disable to be closer to finding root cause?
> >
> > Could you let me know more about the setup? A couple things come to my mind:
> >
> > 1. zswap configs (allocator - is it zsmalloc? compressor?)
>
> Well - I’m not using zswap.

But the bug happens in zswap path? :)

Could you do:

grep . /sys/module/zswap/parameters/*


>
> [root@minimyth2-aarch64-next piotro]# swapon -s
> Filename                                Type            Size            Used            Priority
> /dev/nvme0n1p3                          partition       16776188        294164          -2
>
> >
> > 2. Is mTHP enabled? mTHP swapout was merged in 6.10, and there seems
>
> I don’t have used config at the moment, but /sys/kernel/mm/transparent_hugepage in I see:
>
> │/hugepages-1024kB
> │/hugepages-128kB
> │/hugepages-16kB
> │/hugepages-2048kB
> │/hugepages-256kB
> │/hugepages-32kB
> │/hugepages-512kB
> │/hugepages-64kB
>
>
> > to be some conflicts with zswap, but Yosry will know more about this
> > than me...
> >
> > 3. Is there any proprietary driver etc.?
> >
>
> Only 2, both ryzen9 monitoring related:
> https://github.com/leogx9r/ryzen_smu/commits/master
> https://github.com/ocerman/zenpower/commits/master
>

The reason I asked this is because I've seen proprietary error
screwing with memory in the past - it was an NVIDIA one though.

https://lore.kernel.org/linux-mm/CAKbZUD1-kqfuV0U+KDKPkQbm=RwzD_A1H3qk_c+bw92CqtMbuw@mail.gmail.com/

Also decompression step failure (albeit in the writeback path)