From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Derek Barbosa <debarbos@redhat.com>
Cc: williams@redhat.com, linux-rt-users@vger.kernel.org, ajhalaney@gmail.com
Subject: Re: [PATCH v2] printk: nbcon: Fix illegal RCU usage on thread wakeup
Date: Mon, 4 Nov 2024 14:50:18 +0100 [thread overview]
Message-ID: <20241104135018.grxgmVTt@linutronix.de> (raw)
In-Reply-To: <ZyjLsAK1z7wcrv4N@debarbos-thinkpadt14sgen2i.remote.csb>
On 2024-11-04 08:27:12 [-0500], Derek Barbosa wrote:
> In debug kernels, printk'ing during the SMP startup of a secondary CPU
> results in a splat on boot that details illegal RCU usage from
> offline CPUs.
>
> This patch aligns rcuwait_has_sleeper() with what currently exists in
> Torvalds' tree, at commit 76f258bf3f2aa, and will avoid the
> aforementioned splat.
>
> Furthermore, this patch makes it so that we avoid the use of hacky
> rcu_derefrencing through the waiter's task struct,and instead leverages
> the correct RCU API with the rcuwait_active() function.
>
> Reported-by: Andrew Halaney <ahalaney@redhat.com>
> Closes: https://lore.kernel.org/linux-rt-users/5x4nejpojrtny37k7l6loewqwuaituq77zc3tkkojvawcuvmml@thwg65fdb3vn
>
> Signed-off-by: Derek Barbosa <debarbos@redhat.com>
Thank you.
You missed John's and mine review tag.
Sebastian
prev parent reply other threads:[~2024-11-04 13:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-04 13:27 [PATCH v2] printk: nbcon: Fix illegal RCU usage on thread wakeup Derek Barbosa
2024-11-04 13:50 ` Sebastian Andrzej Siewior [this message]
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