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Message-ID: <79196679-fb65-e5ad-e836-2c43447cfacd@gmail.com>
Date:   Sun, 2 Jul 2023 18:57:05 +0700
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Subject: Re: Fwd: RCU stalls with wireguard over bonding over igb on Linux
 6.3.0+
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From:   Bagas Sanjaya <bagasdotme@gmail.com>
To:     Eric DeVolder <eric.devolder@oracle.com>,
        "Borislav Petkov (AMD)" <bp@alien8.de>,
        David R <david@unsolicited.net>,
        Boris Ostrovsky <boris.ovstrosky@oracle.com>,
        Miguel Luis <miguel.luis@oracle.com>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Jay Vosburgh <j.vosburgh@gmail.com>,
        Andy Gospodarek <andy@greyhouse.net>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        Thorsten Leemhuis <regressions@leemhuis.info>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Regressions <regressions@lists.linux.dev>,
        Linux RCU <rcu@vger.kernel.org>,
        Wireguard Mailing List <wireguard@lists.zx2c4.com>,
        Linux Networking <netdev@vger.kernel.org>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        Manuel 'satmd' Leiner <manuel.leiner@gmx.de>
References: <e5b76a4f-81ae-5b09-535f-114149be5069@gmail.com>
In-Reply-To: <e5b76a4f-81ae-5b09-535f-114149be5069@gmail.com>
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[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