On Mon 2016-04-04 11:38:19, Petr Mladek wrote:
> On Mon 2016-04-04 13:49:28, Sergey Senozhatsky wrote:
> > Hello,
> >
> > On (03/30/16 17:53), Petr Mladek wrote:
> > > +/*
> > > + * Flush data from the associated per_CPU buffer. The function
> > > + * can be called either via IRQ work or independe
On Mon 2016-04-04 13:49:28, Sergey Senozhatsky wrote:
> Hello,
>
> On (03/30/16 17:53), Petr Mladek wrote:
> [..]
> > @@ -67,10 +67,12 @@ extern void irq_exit(void);
> > preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
> > rcu_nmi_enter();\
Hello,
On (03/30/16 17:53), Petr Mladek wrote:
[..]
> @@ -67,10 +67,12 @@ extern void irq_exit(void);
> preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
> rcu_nmi_enter();\
> trace_hardirq_enter();
printk() takes some locks and could not be used a safe way in NMI context.
The chance of a deadlock is real especially when printing stacks from all
CPUs. This particular problem has been addressed on x86 by the commit
a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs").
The pat
