Re: Bug#1093243: Upgrade to 6.1.123 kernel causes mariadb hangs

[Pavel Begunkov <asml.silence@gmail.com>]

On 1/23/25 20:49, Salvatore Bonaccorso wrote:
> Hi Xan,
> 
> On Thu, Jan 23, 2025 at 02:31:34PM -0600, Xan Charbonnet wrote:
>> I rented a Linode and have been trying to load it down with sysbench
>> activity while doing a mariabackup and a mysqldump, also while spinning up
>> the CPU with zstd benchmarks.  So far I've had no luck triggering the fault.
>>
>> I've also been doing some kernel compilation.  I followed this guide:
>> https://www.dwarmstrong.org/kernel/
>> (except that I used make -j24 to build in parallel and used make
>> localmodconfig to compile only the modules I need)
>>
>> I've built the following kernels:
>> 6.1.123 (equivalent to linux-image-6.1.0-29-amd64)
>> 6.1.122
>> 6.1.121
>> 6.1.120
>>
>> So far they have all exhibited the behavior.  Next up is 6.1.119 which is
>> equivalent to linux-image-6.1.0-28-amd64.  My expectation is that the fault
>> will not appear for this kernel.
>>
>> It looks like the issue is here somewhere:
>> https://www.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.120
>>
>> I have to work on some other things, and it'll take a while to prove the
>> negative (that is, to know that the failure isn't happening).  I'll post
>> back with the 6.1.119 results when I have them.
> 
> Additionally please try with 6.1.120 and revert this commit
> 
> 3ab9326f93ec ("io_uring: wake up optimisations")
> 
> (which landed in 6.1.120).
> 
> If that solves the problem maybe we miss some prequisites in the 6.1.y
> series here?

I'm not sure why the commit was backported (need to look it up),
but from a quick look it does seem to miss a barrier present in
the original patch.

-- 
Pavel Begunkov