From 57f2ffe14fd125c240babd88b99d8a57d3ed060e Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Mon, 15 Sep 2014 10:50:47 +0200
Subject: [PATCH] s390: remove diag 44 calls from cpu_relax()
Simplify cpu_relax() to a simple barrier(). Performance wise this doesn't
seem to make any big difference anymore, since nearly all lock variants
have directed yield semantics in the meantime.
Also this makes s390 behave like all other architectures.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/include/asm/processor.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index d559bdb03d1832..bed05ea7ec27eb 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -217,8 +217,6 @@ static inline unsigned short stap(void)
*/
static inline void cpu_relax(void)
{
- if (MACHINE_HAS_DIAG44)
- asm volatile("diag 0,0,68");
barrier();
}
--
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