Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup

[Steven Rostedt]

On Fri, 12 Jan 2018 13:55:37 +0100
Petr Mladek <pmladek@xxxxxxxx> wrote:

> > I'm not fixing console_unlock(), I'm fixing printk(). BTW, all my
> > kernels are CONFIG_PREEMPT (I'm a RT guy), my mind thinks more about
> > PREEMPT kernels than !PREEMPT ones.  
> 
> I would say that the patch improves also console_unlock() but only in
> non-preemttive context.
> 
> By other words, it makes console_unlock() finite in preemptible context
> (limited by buffer size). It might still be unlimited in
> non-preemtible context.

Since I'm worried most about printk(), I would argue to make printk
console unlock always non-preempt.

	preempt_disable();
	if (console_trylock_spinning())
		console_unlock();
	preempt_enable();

-- Steve