[PATCH] x86: all cpu backtrace
When a spinlock lockup occurs, arrange for the NMI code to emit an all-cpu
backtrace, so we get to see which CPU is holding the lock, and where.
Cc: Andi Kleen <ak@muc.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index e16904e..acb4ed1 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -15,9 +15,14 @@
* disables interrupts for a long time. This call is stateless.
*/
#ifdef ARCH_HAS_NMI_WATCHDOG
+#include <asm/nmi.h>
extern void touch_nmi_watchdog(void);
#else
# define touch_nmi_watchdog() touch_softlockup_watchdog()
#endif
+#ifndef trigger_all_cpu_backtrace
+#define trigger_all_cpu_backtrace() do { } while (0)
+#endif
+
#endif