From: Gu Bowen <gubowen5@huawei.com>
To: John Ogness <john.ogness@linutronix.de>,
Waiman Long <llong@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
<stable@vger.kernel.org>, <linux-mm@kvack.org>,
Lu Jialin <lujialin4@huawei.com>,
Breno Leitao <leitao@debian.org>
Subject: Re: [PATCH] mm: Fix possible deadlock in console_trylock_spinning
Date: Thu, 7 Aug 2025 11:22:09 +0800 [thread overview]
Message-ID: <6e278baf-c6e4-49ee-9880-6c15a2c1b996@huawei.com> (raw)
In-Reply-To: <84h5yko44i.fsf@jogness.linutronix.de>
On 8/6/2025 11:34 PM, John Ogness wrote:
>
> printk no longer works like this. There are no special per-CPU
> buffers. As correctly pointed out by Longman, the proper interface is
> printk_deferred_enter()/printk_deferred_exit().
>
> With the deferred interface, the printk message is still immediately
> stored in the printk ringbuffer (which is lockless) and only the console
> printing itself is deferred.
>
Hi,
I agree that printk_deferred_enter()/printk_deferred_exit() is a better
interface, but I noticed that in stable-5.10, the printk safety mode
still uses a per-CPU buffer to store messages through the
printk_safe_log_store function.
Additionally, the mainline version has already refactored printk, so
this issue no longer exists.
next prev parent reply other threads:[~2025-08-07 3:22 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-30 9:49 Gu Bowen
2025-08-01 22:33 ` Andrew Morton
2025-08-02 3:09 ` Waiman Long
2025-08-02 3:53 ` Andrew Morton
2025-08-04 12:08 ` Catalin Marinas
2025-08-04 12:34 ` Breno Leitao
2025-08-04 18:28 ` Catalin Marinas
2025-08-05 7:44 ` Gu Bowen
2025-08-06 15:34 ` John Ogness
2025-08-07 3:22 ` Gu Bowen [this message]
2025-08-01 23:52 ` Andrew Morton
2025-08-11 14:33 ` Petr Mladek
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