The IRQs off tracer enables mcount which has a big impact on
performance. Disable it.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: linux-powerpc/arch/powerpc/configs/ppc64_defconfig
===================================================================
--- linux-powerpc.orig/arch/powerpc/configs/ppc64_defconfig	2011-07-07 09:07:26.482898262 +1000
+++ linux-powerpc/arch/powerpc/configs/ppc64_defconfig	2011-07-07 09:07:29.932959288 +1000
@@ -446,7 +446,6 @@ CONFIG_DEBUG_MUTEXES=y
 # CONFIG_RCU_CPU_STALL_DETECTOR is not set
 CONFIG_LATENCYTOP=y
 CONFIG_SYSCTL_SYSCALL_CHECK=y
-CONFIG_IRQSOFF_TRACER=y
 CONFIG_SCHED_TRACER=y
 CONFIG_BLK_DEV_IO_TRACE=y
 CONFIG_DEBUG_STACKOVERFLOW=y


