From: Petr Mladek <pmladek@suse.com>
To: Sang-Heon Jeon <ekffu200098@gmail.com>
Cc: John Ogness <john.ogness@linutronix.de>,
linux-kernel@vger.kernel.org,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v2] printk: increase the ring buffer for more than 16 CPUs by default
Date: Tue, 29 Sep 2026 17:08:30 +0200 [thread overview]
Message-ID: <arvUbm5ECzXfa02K@pathway.suse.cz> (raw)
In-Reply-To: <20260927091756.50831-1-ekffu200098@gmail.com>
On Sun 2026-09-27 18:17:54, Sang-Heon Jeon wrote:
> The default LOG_BUF_SHIFT is 17, which means 128 KB, and
> LOG_CPU_MAX_BUF_SHIFT is 12, which means 4 KB per CPU.
>
> By default the ring buffer is increased when
> (num_possible_cpus() - 1) * 4 KB > 64 KB, which requires more than 17
> CPUs.
>
> Remove the explicit subtraction of one, so the ring buffer is increased
> for more than 16 CPUs, which is a power of two. Also fix the outdated
> comment.
>
> Suggested-by: Petr Mladek <pmladek@suse.com>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
JFYI, the patch has been comitted into printk/linux.git,
branch for-7.4.
Best Regards,
Petr
prev parent reply other threads:[~2026-09-29 15:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-27 9:17 Sang-Heon Jeon
2026-09-27 16:09 ` John Ogness
2026-09-29 13:54 ` Petr Mladek
2026-09-29 15:08 ` Petr Mladek [this message]
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