Add CONFIG_PREEMPTION.

arch/sparc64/Config.help

@@ -25,6 +25,16 @@ CONFIG_SMP
 
   If you don't know what to do here, say N.
 
+CONFIG_PREEMPT
+  This option reduces the latency of the kernel when reacting to
+  real-time or interactive events by allowing a low priority process to
+  be preempted even if it is in kernel mode executing a system call.
+  This allows applications to run more reliably even when the system is
+  under load.
+
+  Say Y here if you are building a kernel for a desktop, embedded
+  or real-time system.  Say N if you are unsure.
+
 CONFIG_SPARC64
   SPARC is a family of RISC microprocessors designed and marketed by
   Sun Microsystems, incorporated.  This port covers the newer 64-bit

arch/sparc64/config.in

@@ -15,6 +15,7 @@ define_bool CONFIG_VT y
 define_bool CONFIG_VT_CONSOLE y
 
 bool 'Symmetric multi-processing support' CONFIG_SMP
+bool 'Preemptible kernel' CONFIG_PREEMPT
 
 # Identify this as a Sparc64 build
 define_bool CONFIG_SPARC64 y