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From: John Ogness <john.ogness@linutronix.de>
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To: Sreenath Vijayan <sreenath.vijayan@sony.com>, Petr Mladek
 <pmladek@suse.com>
Cc: corbet@lwn.net, gregkh@linuxfoundation.org, jirislaby@kernel.org,
 rdunlap@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org,
 linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-serial@vger.kernel.org, taichi.shimoyashiki@sony.com,
 daniel.palmer@sony.com, anandakumar.balasubramaniam@sony.com,
 sreenath.vijayan@sony.com
Subject: Re: [PATCH v4 2/2] tty/sysrq: Dump printk ring buffer messages via
 sysrq
In-Reply-To: <ZcygJOj9TaHZUKd-@sony.com>
References: <cover.1706772349.git.sreenath.vijayan@sony.com>
 <ca8dd18e434f309612c907d90e9f77c09e045b37.1706772349.git.sreenath.vijayan@sony.com>
 <ZcOdLrOPiPJmCec5@alley> <ZcygJOj9TaHZUKd-@sony.com>
Date: Mon, 26 Feb 2024 10:34:06 +0106
Message-ID: <87h6hvmv6h.fsf@jogness.linutronix.de>
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On 2024-02-14, Sreenath Vijayan <sreenath.vijayan@sony.com> wrote:
> //in printk.c
> void console_replay_all(void)
> {
>        if (console_trylock()) {
>                __console_rewind_all();
>                console_unlock();
>        }
> }
>
> //in sysrq.c
> static void sysrq_handle_dmesg_dump(u8 key)
> {
>        int orig_log_level = console_loglevel;
>        console_loglevel = CONSOLE_LOGLEVEL_DEFAULT;
>        console_replay_all();
>        console_loglevel = orig_log_level;
> }

Note that there is already a sysrq 0-9 to change the loglevel. That may
be more appropriate.

John