[PATCH 3/5] s390: make cpu_relax a barrier again

From	Christian Borntraeger <borntraeger@de.ibm.com>
Newsgroups	linux.kernel
Subject	[PATCH 3/5] s390: make cpu_relax a barrier again
Date	2016-10-21 14:00 +0200
Message-ID	<suGEq-509-19@gated-at.bofh.it> (permalink)
References	<suGEq-509-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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stop_machine seems to be the only important place for yielding during
cpu_relax. This was fixed by using cpu_relax_yield. Therefore, we can
now redefine cpu_relax to be a barrier instead. (With the option to do
some SMT tuning later on)

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/include/asm/processor.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index d05965b..5d262cf 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -236,7 +236,7 @@ static inline unsigned short stap(void)
  */
 void cpu_relax_yield(void);
 
-#define cpu_relax() cpu_relax_yield()
+#define cpu_relax() barrier()
 #define cpu_relax_lowlatency()  barrier()
 
 #define ECAG_CACHE_ATTRIBUTE	0
-- 
2.5.5

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[PATCH 3/5] s390: make cpu_relax a barrier again Christian Borntraeger <borntraeger@de.ibm.com> - 2016-10-21 14:00 +0200

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