From 42ce390ad9a3874337261b470fe1630cd3be27b1 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 5 Aug 2014 09:57:51 +0200 Subject: s390/locking: Reenable optimistic spinning commit 36e7fdaa1a04fcf65b864232e1af56a51c7814d6 upstream. 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 Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/s390') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index bb74b21f007a..a0a3bed6e4dc 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -93,6 +93,7 @@ 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 -- cgit v1.2.3