Re: [tip:locking/urgent] locking/mutex: Disable optimistic spinning on some architectures

Christian Borntraeger
2014-07-17T11:51:43Z

s390: s390 also supports proper atomic read modify write,

There is no need to disable mutex spinning. The instructions
CS,CSG and friends provide the proper guarantees. (We dont
implement cmpxchg with locks).

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index bb63499..8c5df31 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -63,6 +63,7 @@ config S390
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_INLINE_READ_LOCK
select ARCH_INLINE_READ_LOCK_BH
select ARCH_INLINE_READ_LOCK_IRQ
--
1.7.9.5