From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Dmitry Safonov <dima@arista.com>
Cc: linux-kernel@vger.kernel.org,
Dmitry Safonov <0x7f454c46@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
John Ogness <john.ogness@linutronix.de>,
Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v3 2/2] printk: Add printk.console_no_auto_verbose boot parameter
Date: Wed, 28 Jul 2021 10:25:19 +0900 [thread overview]
Message-ID: <YQCx/8bvaJjoKLAs@google.com> (raw)
In-Reply-To: <20210727130635.675184-3-dima@arista.com>
On (21/07/27 14:06), Dmitry Safonov wrote:
> console_verbose() increases console loglevel to CONSOLE_LOGLEVEL_MOTORMOUTH,
> which provides more information to debug a panic/oops.
>
> Unfortunately, in Arista we maintain some DUTs (Device Under Test) that
> are configured to have 9600 baud rate. While verbose console messages
> have their value to post-analyze crashes, on such setup they:
> - may prevent panic/oops messages being printed
> - take too long to flush on console resulting in watchdog reboot
>
> In all our setups we use kdump which saves dmesg buffer after panic,
> so in reality those extra messages on console provide no additional value,
> but rather add risk of not getting to __crash_kexec().
>
> Provide printk.console_no_auto_verbose boot parameter, which allows
> to switch off printk being verbose on oops/panic/lockdep.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: John Ogness <john.ogness@linutronix.de>
> Cc: Petr Mladek <pmladek@suse.com>
> Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Dmitry Safonov <dima@arista.com>
> Suggested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
prev parent reply other threads:[~2021-07-28 1:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-27 13:06 [PATCH v3 0/2] printk: Add printk.no_console_auto_verbose boot param Dmitry Safonov
2021-07-27 13:06 ` [PATCH v3 1/2] printk: Remove console_silent() Dmitry Safonov
2021-07-28 1:23 ` Sergey Senozhatsky
2021-07-27 13:06 ` [PATCH v3 2/2] printk: Add printk.console_no_auto_verbose boot parameter Dmitry Safonov
2021-07-28 1:25 ` Sergey Senozhatsky [this message]
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