Re: [RFC][PATCH] printk: Fixup the nmi printk mess

Steven Rostedt
2015-06-10T15:54:35Z

On Wed, 10 Jun 2015 17:32:53 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> > Note that the backtraces used to be serialized via
> > static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED
> > in the past. See the commit
> > a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs")
>
> We could easily add a static raw_spinlock_t to __printk_nmi_flush() and
> serialize its invocations if people think that is important.

Yes please. One thing about the original change is that it made the NMI
backtraces readable. I hated the interleaving of the backtraces, as it
made it almost impossible to to debug.

-- Steve