[tip:core/ipi] generic-ipi: eliminate WARN_ON()s during oops/panic

[Ingo Molnar]

Commit-ID:  641cd4cfcdc71ce01535b31cc4d57d59a1fae1fc
Gitweb:     http://git.kernel.org/tip/641cd4cfcdc71ce01535b31cc4d57d59a1fae1fc
Author:     Ingo Molnar <mingo@xxxxxxx>
AuthorDate: Fri, 13 Mar 2009 10:47:34 +0100
Commit:     Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 13 Mar 2009 10:47:34 +0100

generic-ipi: eliminate WARN_ON()s during oops/panic

Do not output smp-call related warnings in the oops/panic codepath.

Reported-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
LKML-Reference: <49B91A7E.76E4.0078.0@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
 kernel/smp.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index 7ad2262..858baac 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -5,6 +5,7 @@
  */
 #include <linux/rcupdate.h>
 #include <linux/rculist.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
 #include <linux/init.h>
@@ -285,7 +286,7 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 	this_cpu = get_cpu();
 
 	/* Can deadlock when called with interrupts disabled */
-	WARN_ON(irqs_disabled());
+	WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
 
 	if (cpu == this_cpu) {
 		local_irq_save(flags);
@@ -329,7 +330,7 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
 	csd_lock(data);
 
 	/* Can deadlock when called with interrupts disabled */
-	WARN_ON(wait && irqs_disabled());
+	WARN_ON_ONCE(wait && irqs_disabled() && !oops_in_progress);
 
 	generic_exec_single(cpu, data, wait);
 }
@@ -365,7 +366,7 @@ void smp_call_function_many(const struct cpumask *mask,
 	int cpu, next_cpu, this_cpu = smp_processor_id();
 
 	/* Can deadlock when called with interrupts disabled */
-	WARN_ON(irqs_disabled());
+	WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
 
 	/* So, what's a CPU they want? Ignoring this one. */
 	cpu = cpumask_first_and(mask, cpu_online_mask);
--
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