[PATCH] Make cpu_relax() imply barrier() on all arches

During the recent discussion of taking 'volatile' off of the spinlock, I
noticed that while most arches #define cpu_relax() such that it implies
barrier(), some arches define cpu_relax() to be empty.

This patch changes the definition of cpu_relax() for frv, h8300, m68knommu,
sh, sh64, v850 and xtensa from an empty while(0) to the compiler barrier().

Signed-off-by: Chase Venters <chase.venters@clientec.com>
Acked-by: Arjan van de Ven <arjan@Linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/asm-v850/processor.h b/include/asm-v850/processor.h
index 6965b66ccaed..979e3467f9af 100644
--- a/include/asm-v850/processor.h
+++ b/include/asm-v850/processor.h
@@ -18,6 +18,7 @@
 #include <linux/thread_info.h>
 #endif
 
+#include <linux/compiler.h>
 #include <asm/ptrace.h>
 #include <asm/entry.h>
 
@@ -106,7 +107,7 @@ unsigned long get_wchan (struct task_struct *p);
 #define KSTK_ESP(task)  task_sp (task)
 
 
-#define cpu_relax()    ((void)0)
+#define cpu_relax()    barrier()
 
 
 #else /* __ASSEMBLY__ */