[PATCH] PPC64 Add PREEMPT_BKL option

This patch adds the PREEMPT_BKL config option for PPC64, shamelessly
stolen from the i386 version.  I have this turned on in the kernel on
my desktop G5 and it seems to be just fine.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/Kconfig

@@ -231,6 +231,17 @@ config PREEMPT
 	  Say Y here if you are building a kernel for a desktop, embedded
 	  or real-time system.  Say N if you are unsure.
 
+config PREEMPT_BKL
+	bool "Preempt The Big Kernel Lock"
+	depends on PREEMPT
+	default y
+	help
+	  This option reduces the latency of the kernel by making the
+	  big kernel lock preemptible.
+
+	  Say Y here if you are building a kernel for a desktop system.
+	  Say N if you are unsure.
+
 #
 # Use the generic interrupt handling code in kernel/irq/:
 #