Re: [PATCH v3 1/2] Allow cpu backtraces to be written into ringbuffer during panic

[Petr Mladek]

On Mon 2024-08-12 16:27:03, takakura@xxxxxxxxxxxxx wrote:
> From: Ryo Takakura <takakura@xxxxxxxxxxxxx>
> 
> commit 779dbc2e78d7 ("printk: Avoid non-panic CPUs writing
> to ringbuffer") disabled non-panic CPUs to further write messages to
> ringbuffer after panicked.
> 
> Since the commit, non-panicked CPU's are not allowed to write to
> ring buffer after panicked and CPU backtrace which is triggered
> after panicked to sample non-panicked CPUs' backtrace no longer
> serves its function as it has nothing to print.
> 
> Fix the issue by allowing non-panicked CPUs to write into ringbuffer
> while CPU backtrace is in flight.
> 
> Fixes: 779dbc2e78d7 ("printk: Avoid non-panic CPUs writing to ringbuffer")
> Signed-off-by: Ryo Takakura <takakura@xxxxxxxxxxxxx>
> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

JFYI, I have pushed this patch into printk/linux.git, branch for-6.11-fixup.
I am going to create pull request after it spends at least one or two
days in linux-next.

The 2nd patch is more complicated. It depends on another patchset
integrating con->write_atomic() callback. 

Best Regards,
Petr