Re: [PATCH v4 0/2] Add support to dump printk buffer to console via sysrq

Petr Mladek
2024-02-07T14:12:14Z

Hi,

first, I am sorry for joining the game so late. I was sick
and have had a lot of pending tasks after Christmas's holidays
and the sickness.

On Thu 2024-02-01 13:12:39, Sreenath Vijayan wrote:
> Hi,
>
> This patch series enables one to dump the messages in printk ring
> buffer unless all CPUs are locked up. This is useful to view the
> kernel messages when terminal is unresponsive to enter commands
> like dmesg and syslog services are also disabled, especially on
> embedded targets.

What is the exact scenario for this feature, please?

IMHO, rewinding the entire log on an unresponsive terminal
has a questionable value. Most messages would scroll down
quickly and only the last messages would stay visible.

Also this code would rewind all consoles, including
(slow) serial ones. I wonder if rewind on these consoles
would be useful as well.

That said, I am not completely against this feature.
I just want to be sure that it does what you expect.

Best Regards,
Petr