Re: [debug patch] printk: Add a printk killswitch to robustify NMIwatchdog messages

[Ingo Molnar]

* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> Needs more staring at, preferably by someone who actually 
> understands that horrid mess :/ Also, this all still doesn't make 
> printk() work reliably while holding rq->lock.

So, what about my suggestion to just *remove* the wakeup from there 
and use the deferred wakeup mechanism that klogd uses.

That would make printk() *visibly* more robust in practice.

[ It would also open up the way to possibly make printk() NMI entry 
  safe - currently we lock up if we printk in an NMI or #MC context 
  that happens to nest inside a printk(). ]

Thanks,

	Ingo
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