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: Jiri Slaby <jslaby@suse.cz>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e47fcd1e964503b125d90a2a2ed93d5d2b1fd85a..99e1ce978cf90df8f2a0bfd6b1612492cd76fed2 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -5,6 +5,7 @@ config ARM
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
        select ARCH_HAVE_CUSTOM_GPIO_H
+       select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_WANT_IPC_PARSE_VERSION
        select BUILDTIME_EXTABLE_SORT if MMU
        select CLONE_BACKWARDS

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c04454876bcbe6520a52ada910a7d193ff884e85..fe70eaea0e28b43301704fac7784460b9e2282d1 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 d5d026b6d237579871dbd756fed7f9b964f70d26..2e0ddfadc0b91d73e3f0b7c5219af03d29015a3f 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -138,6 +138,7 @@ config PPC
        select OLD_SIGSUSPEND
        select OLD_SIGACTION if PPC32
        select HAVE_DEBUG_STACKOVERFLOW
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config EARLY_PRINTK
        bool

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 4e5683877b934c93557376cc7d850ee3b5d63d9a..d60f34dbae890e054ea137cbb601a8b989c732b1 100644 (file)
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -75,6 +75,7 @@ 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 eb2dfa61eabe569d2a5125ae334132576360e551..9dc1a24d41b83c0a6db22fb82a438f817c4d8078 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -123,6 +123,7 @@ config X86
        select COMPAT_OLD_SIGACTION if IA32_EMULATION
        select RTC_LIB
        select HAVE_DEBUG_STACKOVERFLOW
+       select ARCH_SUPPORTS_ATOMIC_RMW
 
 config INSTRUCTION_DECODER
        def_bool y

diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index d2b32ac27a394095e87229030e010eb428ae7174..ecee67a00f5f68ee2818d52d3bcfe5ba38afe252 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