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authorChristian Borntraeger <borntraeger@de.ibm.com>2014-08-05 09:57:51 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-08-06 11:44:43 +0200
commit36e7fdaa1a04fcf65b864232e1af56a51c7814d6 (patch)
treefdc1603d6ea44a5c9033f4d1804d982e23708b71
parent152125b7a882df36a55a8eadbea6d0edf1461ee7 (diff)
downloadtalos-op-linux-36e7fdaa1a04fcf65b864232e1af56a51c7814d6.tar.gz
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s390/locking: Reenable optimistic spinning
commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc (locking/mutex: Disable optimistic spinning on some architectures) fenced spinning for architectures without proper cmpxchg. There is no need to disable mutex spinning on s390, though: 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> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index bb63499fc5d3..9f00f9301613 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -92,6 +92,7 @@ config S390
select ARCH_INLINE_WRITE_UNLOCK_IRQ
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
select ARCH_SAVE_PAGE_KEYS if HIBERNATION
+ select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_EXTABLE_SORT
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