From: Johannes Berg <johannes@sipsolutions.net>
To: Sasha Levin <sashal@kernel.org>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>,
anton.ivanov@cambridgegreys.com, mst@redhat.com,
jiri@resnulli.us, tglx@linutronix.de, viro@zeniv.linux.org.uk,
krzysztof.kozlowski@linaro.org, herve.codina@bootlin.com,
linux-um@lists.infradead.org
Subject: Re: [PATCH AUTOSEL 6.6 14/17] um: virt-pci: don't use kmalloc()
Date: Wed, 19 Feb 2025 08:42:01 +0100 [thread overview]
Message-ID: <c993aa3a8e86e429d2135974929283a33d0f34ca.camel@sipsolutions.net> (raw)
In-Reply-To: <20250218202743.3593296-14-sashal@kernel.org>
On Tue, 2025-02-18 at 15:27 -0500, Sasha Levin wrote:
> From: Johannes Berg <johannes.berg@intel.com>
>
> [ Upstream commit 5b166b782d327f4b66190cc43afd3be36f2b3b7a ]
>
> This code can be called deep in the IRQ handling, for
> example, and then cannot normally use kmalloc(). Have
> its own pre-allocated memory and use from there instead
> so this doesn't occur. Only in the (very rare) case of
> memcpy_toio() we'd still need to allocate memory.
I don't believe this patch, "um: convert irq_lock to raw spinlock" and
"um: virtio_uml: use raw spinlock", are relevant to anything older than
6.12. I don't see how applying them would _hurt_, but I didn't have them
before 6.12 and had no lockdep complaints about it; I believe some other
internal IRQ rework caused the issues to pop up.
Never mind that we (Intel WiFi stuff) are probably the only ones ever
running this virtio_uml/virt-pci with lockdep :)
johannes
next prev parent reply other threads:[~2025-02-19 7:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20250218202743.3593296-1-sashal@kernel.org>
2025-02-18 20:27 ` [PATCH AUTOSEL 6.6 14/17] um: virt-pci: don't use kmalloc() Sasha Levin
2025-02-19 7:42 ` Johannes Berg [this message]
2025-03-15 1:29 ` Sasha Levin
2025-02-18 20:27 ` [PATCH AUTOSEL 6.6 15/17] um: virtio_uml: use raw spinlock Sasha Levin
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