[PATCH] lockdep: stacktrace subsystem, core

Framework to generate and save stacktraces quickly, without printing anything
to the console.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 7b3863d..04e374c 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -107,7 +107,7 @@
 
 config DEBUG_PREEMPT
 	bool "Debug preemptible kernel"
-	depends on DEBUG_KERNEL && PREEMPT
+	depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
 	default y
 	help
 	  If you say Y here then the kernel will use a debug variant of the
@@ -149,6 +149,10 @@
 	  If you say Y here, various routines which may sleep will become very
 	  noisy if they are called with a spinlock held.
 
+config STACKTRACE
+	bool
+	depends on STACKTRACE_SUPPORT
+
 config DEBUG_KOBJECT
 	bool "kobject debugging"
 	depends on DEBUG_KERNEL