locking/mutex: Disable optimistic spinning on some architectures

commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc upstream.

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: 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 18a9f5ef643ad2253f6e7863c2a24f049663bc4a..d41951246cd6f831fa8660e188257819ccc6cc02 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -4,6 +4,7 @@ config ARM
        select ARCH_BINFMT_ELF_RANDOMIZE_PIE
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAVE_CUSTOM_GPIO_H
+       select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
        select ARCH_WANT_IPC_PARSE_VERSION
        select BUILDTIME_EXTABLE_SORT if MMU

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 56b3f6d447ae10b8d53f9cfb767826fe90a97c11..0677ff4814fa0f9bd16661a539b7b787a0a4d591 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1,6 +1,7 @@
 config ARM64
        def_bool y
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+       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 fe404e77246ed47e87bd47d2b9e88b7192dcfed4..7f656f119ea67513eb7aab29419aebf79a19e7de 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -138,6 +138,7 @@ config PPC
        select ARCH_USE_BUILTIN_BSWAP
        select OLD_SIGSUSPEND
        select OLD_SIGACTION if PPC32
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config EARLY_PRINTK
        bool

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 2668b3142fa2a0f00c120cf55d7dc3e90a0338dc..03a1bc3c3ddea4fd1bb5239463e160e221007dc1 100644 (file)
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -77,6 +77,7 @@ config SPARC64
        select ARCH_HAVE_NMI_SAFE_CMPXCHG
        select HAVE_C_RECORDMCOUNT
        select NO_BOOTMEM
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config ARCH_DEFCONFIG
        string

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fe120da25625b23ef52c74b479bf715f265261b4..af88b27ce313fa76ee479b3adc5347baecabc9d9 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -121,6 +121,7 @@ config X86
        select OLD_SIGACTION if X86_32
        select COMPAT_OLD_SIGACTION if IA32_EMULATION
        select RTC_LIB
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config INSTRUCTION_DECODER
        def_bool y

diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index 44511d100eaa89f73c53f0e16828a9f03d7256ac..e4d30533c562c1eb810d890707d74d332a147aa9 100644 (file)
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -220,6 +220,9 @@ 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