Re: [RFC][PATCHv2 4/8] pm: switch to printk.emergency mode in unsafe places

From: Petr Mladek
Date: Fri Mar 31 2017 - 11:06:26 EST


On Wed 2017-03-29 18:25:07, Sergey Senozhatsky wrote:
> It's not always possible/safe to wake_up() printk kernel
> thread. For example, late suspend/early resume may printk()
> while timekeeping is not initialized yet, so calling into the
> scheduler may result in recursive warnings.
>
> Another thing to notice is the fact PM at some point
> freezes user space and kernel threads: freeze_processes()
> and freeze_kernel_threads(), correspondingly. Thus we need
> printk() to operate in old mode there and attempt to
> immediately flush pending kernel message to the console.
>
> This patch adds printk_emergency_begin/on sections.
>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>

It looks reasonable to me. Feel free to use:

Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Well, it still would be great if people more familiar
with this code look at it.

Best Regards,
Petr