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 <peterz@infradead.org>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: stable@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 245058b..88acf8b 100644 (file)
--- 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 a474de3..839f48c 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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