* [PATCH 3.14 81/87] locking/mutex: Disable optimistic spinning on some architectures
[not found] <20140726190214.530473925@linuxfoundation.org>
@ 2014-07-26 19:02 ` Greg Kroah-Hartman
0 siblings, 0 replies; only message in thread
From: Greg Kroah-Hartman @ 2014-07-26 19:02 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Zijlstra, Will Deacon, James Bottomley, Davidlohr Bueso,
sparclinux, Ingo Molnar, Russell King, James E.J. Bottomley,
Linus Torvalds, Catalin Marinas, Paul McKenney, James Hogan,
Chris Metcalf, Mikulas Patocka, John David Anglin,
linux-arm-kernel, Jason Low, Waiman Long, Greg Kroah-Hartman,
stable, Vineet Gupta, linuxppc-dev, David Miller
3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Peter Zijlstra <peterz@infradead.org>
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>
---
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(-)
--- 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
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2,6 +2,7 @@ config ARM64
def_bool y
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_USE_CMPXCHG_LOCKREF
+ select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_WANT_OPTIONAL_GPIOLIB
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_IRQ_EXIT_ON_IRQ_STACK
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
+ select ARCH_SUPPORTS_ATOMIC_RMW
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
--- 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
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -127,6 +127,7 @@ config X86
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
select HAVE_CC_STACKPROTECTOR
+ select ARCH_SUPPORTS_ATOMIC_RMW
config INSTRUCTION_DECODER
def_bool y
--- 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
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