[PATCH] x86: __force_order doesn't need to be an actual variable

[PATCH] x86: __force_order doesn't need to be an actual variable

[Jan Beulich]

It being static causes over a dozen instances to be scattered across
the kernel image, with non of them ever being referenced in any way.
Making the variable extern without ever defining it works as well - all
we need is to have the compiler think the variable is being accessed.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

---
 arch/x86/include/asm/special_insns.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 3.10-rc3/arch/x86/include/asm/special_insns.h
+++ 3.10-rc3-x86-force-order/arch/x86/include/asm/special_insns.h
@@ -16,7 +16,7 @@ static inline void native_clts(void)
  * all loads stores around it, which can hurt performance. Solution is to
  * use a variable and mimic reads and writes to it to enforce serialization
  */
-static unsigned long __force_order;
+extern unsigned long __force_order;
 
 static inline unsigned long native_read_cr0(void)
 {

[tip:x86/asm] x86: __force_order doesn' t need to be an actual variable

[tip-bot for Jan Beulich]

Commit-ID:  1d10f6ee602ec5a4bd0c1606ba5f38277da432e1
Gitweb:     http://git.kernel.org/tip/1d10f6ee602ec5a4bd0c1606ba5f38277da432e1
Author:     Jan Beulich <JBeulich@suse.com>
AuthorDate: Wed, 29 May 2013 13:29:12 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 31 May 2013 13:09:17 +0200

x86: __force_order doesn't need to be an actual variable

It being static causes over a dozen instances to be scattered
across the kernel image, with non of them ever being referenced
in any way. Making the variable extern without ever defining it
works as well - all we need is to have the compiler think the
variable is being accessed.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/51A610B802000078000D99A0@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/special_insns.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 41fc93a..2f4d924 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -16,7 +16,7 @@ static inline void native_clts(void)
  * all loads stores around it, which can hurt performance. Solution is to
  * use a variable and mimic reads and writes to it to enforce serialization
  */
-static unsigned long __force_order;
+extern unsigned long __force_order;
 
 static inline unsigned long native_read_cr0(void)
 {