Re: Fwd: RCU stalls with wireguard over bonding over igb on Linux 6.3.0+

From: Bagas Sanjaya
Date: Sun Jul 02 2023 - 07:57:53 EST


[also Cc: original reporter]

On 7/2/23 10:31, Bagas Sanjaya wrote:
> Hi,
>
> I notice a regression report on Bugzilla [1]. Quoting from it:
>
>> I've spent the last week on debugging a problem with my attempt to upgrade my kernel from 6.2.8 to 6.3.8 (now also with 6.4.0 too).
>>
>> The lenghty and detailed bug reports with all aspects of git bisect are at
>> https://bugs.gentoo.org/909066
>>
>> A summary:
>> - if I do not configure wg0, the kernel does not hang
>> - if I use a kernel older than commit fed8d8773b8ea68ad99d9eee8c8343bef9da2c2c, it does not hang
>>
>> The commit refers to code that seems unrelated to the problem for my naiive eye.
>>
>> The hardware is a Dell PowerEdge R620 running Gentoo ~amd64.
>>
>> I have so far excluded:
>> - dracut for generating the initramfs is the same version over all kernels
>> - linux-firmware has been the same
>> - CPU microcode has been the same
>>
>> It's been a long time since I seriously involved with software development and I have been even less involved with kernel development.
>>
>> Gentoo maintainers recommended me to open a bug with upstream, so here I am.
>>
>> I currently have no idea how to make progress, but I'm willing to try things.
>
> See Bugzilla for the full thread.
>
> Anyway, I'm adding it to regzbot to make sure it doesn't fall through cracks
> unnoticed:
>
> #regzbot introduced: fed8d8773b8ea6 https://bugzilla.kernel.org/show_bug.cgi?id=217620
> #regzbot title: correcting acpi_is_processor_usable() check causes RCU stalls with wireguard over bonding+igb
> #regzbot link: https://bugs.gentoo.org/909066
>

satmd: Can you repeat bisection to confirm that fed8d8773b8ea6 is
really the culprit?

Thorsten: It seems like the reporter concluded bisection to the
(possibly) incorrect culprit. What can I do in this case besides
asking to repeat bisection?

--
An old man doll... just what I always wanted! - Clara