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

[Pavel Machek]

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>

I don't like this. It is symptom of printk getting much more fragile
now.

								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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