Date: Wed, 10 Jun 2015 11:54:11 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.cz>, linux-kernel@vger.kernel.org,
        jkosina@suse.cz, paulmck@linux.vnet.ibm.com,
        Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC][PATCH] printk: Fixup the nmi printk mess
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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
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