Commit-ID:  4badad352a6bb202ec68afa7a574c0bb961e5ebc
Gitweb:     http://git.kernel.org/tip/4badad352a6bb202ec68afa7a574c0bb961e5ebc
Author:     Peter Zijlstra <[email protected]>
AuthorDate: Fri, 6 Jun 2014 19:53:16 +0200
Committer:  Ingo Molnar <[email protected]>
CommitDate: Wed, 16 Jul 2014 14:57:07 +0200

locking/mutex: Disable optimistic spinning on some architectures

The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.

There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.

Opt in for known good archs.

Signed-off-by: Peter Zijlstra <[email protected]>
Reported-by: Mikulas Patocka <[email protected]>
Cc: David Miller <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Jason Low <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Paul McKenney <[email protected]>
Cc: John David Anglin <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: [email protected]
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Russell King <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
 arch/arm/Kconfig     | 1 +
 arch/arm64/Kconfig   | 1 +
 arch/powerpc/Kconfig | 1 +
 arch/sparc/Kconfig   | 1 +
 arch/x86/Kconfig     | 1 +
 kernel/Kconfig.locks | 5 ++++-
 6 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 245058b..88acf8b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -6,6 +6,7 @@ config ARM
        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
        select ARCH_HAVE_CUSTOM_GPIO_H
        select ARCH_MIGHT_HAVE_PC_PARPORT
+       select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_USE_BUILTIN_BSWAP
        select ARCH_USE_CMPXCHG_LOCKREF
        select ARCH_WANT_IPC_PARSE_VERSION
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a474de34..839f48c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -4,6 +4,7 @@ config ARM64
        select ARCH_HAS_OPP
        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
        select ARCH_USE_CMPXCHG_LOCKREF
+       select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_WANT_OPTIONAL_GPIOLIB
        select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
        select ARCH_WANT_FRAME_POINTERS
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index fefe7c8..80b94b0 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -145,6 +145,7 @@ config PPC
        select HAVE_IRQ_EXIT_ON_IRQ_STACK
        select ARCH_USE_CMPXCHG_LOCKREF if PPC64
        select HAVE_ARCH_AUDITSYSCALL
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config GENERIC_CSUM
        def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 29f2e98..407c87d 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -78,6 +78,7 @@ config SPARC64
        select HAVE_C_RECORDMCOUNT
        select NO_BOOTMEM
        select HAVE_ARCH_AUDITSYSCALL
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config ARCH_DEFCONFIG
        string
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a8f749e..d24887b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -131,6 +131,7 @@ config X86
        select HAVE_CC_STACKPROTECTOR
        select GENERIC_CPU_AUTOPROBE
        select HAVE_ARCH_AUDITSYSCALL
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config INSTRUCTION_DECODER
        def_bool y
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index 35536d9..8190794 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -220,9 +220,12 @@ config INLINE_WRITE_UNLOCK_IRQRESTORE
 
 endif
 
+config ARCH_SUPPORTS_ATOMIC_RMW
+       bool
+
 config MUTEX_SPIN_ON_OWNER
        def_bool y
-       depends on SMP && !DEBUG_MUTEXES
+       depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW
 
 config ARCH_USE_QUEUE_RWLOCK
        bool
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to