From: Rob Herring <rob.herring@calxeda.com>
Date: Fri, 4 Mar 2011 22:51:59 +0000 (+0100)
Subject: ARM: 6786/1: enable CONFIG_KTIME_SCALAR
X-Git-Tag: v3.12-rc1~6920^2~2^2~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bf9dd36091695f1138a98b6ae85d565e60635545;p=kernel%2Fkernel-generic.git

ARM: 6786/1: enable CONFIG_KTIME_SCALAR

Use straight 64-bit values as 64-bit operations are fairly efficient on ARM.
Comparing the asm output with and without KTIME_SCALAR, using 64-bit math
generates clearly better code.

Comparing kernel/hrtimer.c .text size, it goes from 0x1414 to 0x119c with
this change.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ef41f7e..2fec707 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -63,6 +63,10 @@ config GENERIC_CLOCKEVENTS_BROADCAST
 	depends on GENERIC_CLOCKEVENTS
 	default y if SMP
 
+config KTIME_SCALAR
+	bool
+	default y
+
 config HAVE_TCM
 	bool
 	select GENERIC_ALLOCATOR