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Subject: [PATCH RT] Use raw spinlocks in NMI print sequencing.
From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>, LKML <linux-kernel@vger.kernel.org>,
       RT <linux-rt-users@vger.kernel.org>
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Date: Tue, 19 Jun 2007 16:11:34 -0400
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Currently NMI uses spinlocks to serialize the prints. We need these to
be raw spinlocks for PREEMPT_RT

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Index: linux-2.6.21-rt9/arch/x86_64/kernel/nmi.c
===================================================================
--- linux-2.6.21-rt9.orig/arch/x86_64/kernel/nmi.c
+++ linux-2.6.21-rt9/arch/x86_64/kernel/nmi.c
@@ -949,7 +949,7 @@ int __kprobes nmi_watchdog_tick(struct p
 	}
 
 	if (cpu_isset(cpu, backtrace_mask)) {
-		static DEFINE_SPINLOCK(lock);	/* Serialise the printks */
+		static DEFINE_RAW_SPINLOCK(lock);	/* Serialise the printks */
 
 		spin_lock(&lock);
 		printk("NMI backtrace for cpu %d\n", cpu);