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authorPeter Zijlstra <peterz@infradead.org>2014-06-06 19:53:16 +0200
committerBen Hutchings <ben@decadent.org.uk>2014-08-06 18:07:38 +0100
commite87c95f8ac1ec35ebf4d144d4b46e2ecf153ffd4 (patch)
treef9f7aa9fb4a60d7974c29a0805c7b597fb698e7d
parent8f88141b2724459ab757b44a5251cd915169f5de (diff)
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> [bwh: Backported to 3.2: - Adjust context - Drop arm64 change] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--arch/arm/Kconfig1
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/sparc/Kconfig1
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--kernel/Kconfig.locks6
5 files changed, 9 insertions, 1 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 790ea68ecf8..082bd366928 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1,6 +1,7 @@
config ARM
bool
default y
+ select ARCH_SUPPORTS_ATOMIC_RMW
select HAVE_DMA_API_DEBUG
select HAVE_IDE if PCI || ISA || PCMCIA
select HAVE_MEMBLOCK
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 16ef838b3cb..bec952d8903 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -137,6 +137,7 @@ config PPC
select HAVE_BPF_JIT if (PPC64 && NET)
select HAVE_ARCH_JUMP_LABEL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_SUPPORTS_ATOMIC_RMW
config EARLY_PRINTK
bool
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 88d442d49ac..f2f3574dcdf 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -57,6 +57,7 @@ config SPARC64
select IRQ_PREFLOW_FASTEOI
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_C_RECORDMCOUNT
+ select ARCH_SUPPORTS_ATOMIC_RMW
config ARCH_DEFCONFIG
string
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fb2e69db9c7..901447e3a42 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -75,6 +75,7 @@ config X86
select HAVE_BPF_JIT if (X86_64 && NET)
select CLKEVT_I8253
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_SUPPORTS_ATOMIC_RMW
config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index 5068e2a4e75..61ebb49bdee 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -198,5 +198,9 @@ config INLINE_WRITE_UNLOCK_IRQ
config INLINE_WRITE_UNLOCK_IRQRESTORE
def_bool !DEBUG_SPINLOCK && ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+config ARCH_SUPPORTS_ATOMIC_RMW
+ bool
+
config MUTEX_SPIN_ON_OWNER
- def_bool SMP && !DEBUG_MUTEXES
+ def_bool y
+ depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW