[PATCH] uml: mark SMP on UML/x86_64 as broken

Noticed by Al Viro <viro@parcelfarce.linux.theplanet.co.uk> - SMP on x86_64 is
fundamentally broken due to UML's reuse of the host arch's percpu stuff.  This
is OK on x86, but the x86_64 pda stuff just won't work for UML.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/Kconfig.x86_64 b/arch/um/Kconfig.x86_64
index 6e5357c..bd35e59 100644
--- a/arch/um/Kconfig.x86_64
+++ b/arch/um/Kconfig.x86_64
@@ -37,3 +37,7 @@
 config ARCH_REUSE_HOST_VSYSCALL_AREA
 	bool
 	default n
+
+config SMP_BROKEN
+	bool
+	default y