[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>
diff --git a/include/asm-v850/processor.h b/include/asm-v850/processor.h
index 6965b66..979e346 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 @@
#define KSTK_ESP(task) task_sp (task)
-#define cpu_relax() ((void)0)
+#define cpu_relax() barrier()
#else /* __ASSEMBLY__ */