From: Bert Karwatzki <spasswolf@web•de>
To: Mateusz Guzik <mjguzik@gmail•com>
Cc: Thomas Gleixner <tglx@linutronix•de>,
spasswolf@web•de, Christian Brauner <brauner@kernel•org>,
spasswolf@web•de, linux-kernel@vger•kernel.org,
linux-next@vger•kernel.org, linux-rt-devel@lists•linux.dev,
linux-fsdevel@vger•kernel.org, adobriyan@gmail•com,
jack@suse•cz, viro@zeniv•linux.org.uk,
Sebastian Andrzej Siewior <bigeasy@linutronix•de>,
Alex Deucher <alexander.deucher@amd•com>,
amd-gfx@lists•freedesktop.org
Subject: Re: context switch within RCU read-side critical section in next-20260518+ with PREEMPT_RT
Date: Thu, 21 May 2026 13:50:48 +0200 [thread overview]
Message-ID: <70676dae700e6a40989315bf31ea269a509ddc0f.camel@web.de> (raw)
In-Reply-To: <CAGudoHGk1CP3gRQLCV85AFHKx6vBEyKySOn4J+AZVAP2FkrN3g@mail.gmail.com>
>
> Can you please do the following:
> 1. go back to the known crashing-tag, add my fix, verify you still get
> the amd splat and then try out the fix provided by Thomas
> 2. regardless if the above helps, can you boot a kernel built with
> CONFIG_KASAN=y
>
> fwiw I verified my patch works fine with KASAN, including by
> intentionally miscalculating the size of the target buffer and seeing
> a nice splat from it so I'm confident I'm not corrupting anything.
> However, as there are new mallocs + free flying around at early boot,
> it is *plausible* amd was getting zeroed memory without asking for it
> and it worked by accident.
I think the warnning from amdgpu is only displayed with CONFIG_LOCKDEP=y, so
your "improved fix" does not silence the warning from amdgpu.
The additional fix from Thomas fixes the amdgpu warning.
I also built the kernel with CONFIG_KASAN and get no error messages.
Bert Karwatzki
next prev parent reply other threads:[~2026-05-21 11:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-20 22:52 context switch within RCU read-side critical section in next-20260518+ with PREEMPT_RT Bert Karwatzki
2026-05-21 8:37 ` Thomas Gleixner
2026-05-21 8:53 ` Mateusz Guzik
2026-05-21 9:08 ` Sebastian Andrzej Siewior
2026-05-21 9:17 ` Mateusz Guzik
2026-05-21 9:09 ` Mateusz Guzik
2026-05-21 9:20 ` Bert Karwatzki
2026-05-21 9:25 ` Mateusz Guzik
2026-05-21 9:57 ` Bert Karwatzki
2026-05-21 10:17 ` Thomas Gleixner
2026-05-21 10:21 ` Bert Karwatzki
2026-05-21 10:33 ` Mateusz Guzik
2026-05-21 11:50 ` Bert Karwatzki [this message]
2026-05-21 12:01 ` Mateusz Guzik
2026-05-28 17:59 ` Bert Karwatzki
2026-05-29 17:20 ` Mateusz Guzik
2026-05-21 10:05 ` Thomas Gleixner
2026-05-21 10:13 ` Bert Karwatzki
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