From: Peter Zijlstra <pet...@infradead.org> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know.
=============== 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 <pet...@infradead.org> Reported-by: Mikulas Patocka <mpato...@redhat.com> Cc: David Miller <da...@davemloft.net> Cc: Chris Metcalf <cmetc...@tilera.com> Cc: James Bottomley <james.bottom...@hansenpartnership.com> Cc: Vineet Gupta <vgu...@synopsys.com> Cc: Jason Low <jason.l...@hp.com> Cc: Waiman Long <waiman.l...@hp.com> Cc: "James E.J. Bottomley" <j...@parisc-linux.org> Cc: Paul McKenney <paul...@linux.vnet.ibm.com> Cc: John David Anglin <dave.ang...@bell.net> Cc: James Hogan <james.ho...@imgtec.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Davidlohr Bueso <davidl...@hp.com> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Russell King <li...@arm.linux.org.uk> Cc: Will Deacon <will.dea...@arm.com> Cc: linux-arm-ker...@lists.infradead.org Cc: linux-ker...@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparcli...@vger.kernel.org Link: http://lkml.kernel.org/r/20140606175316.gv13...@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Jiri Slaby <jsl...@suse.cz> --- 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(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e47fcd1e9645..99e1ce978cf9 100644 --- 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 c04454876bcb..fe70eaea0e28 100644 --- 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 d5d026b6d237..2e0ddfadc0b9 100644 --- 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 4e5683877b93..d60f34dbae89 100644 --- 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 eb2dfa61eabe..9dc1a24d41b8 100644 --- 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 d2b32ac27a39..ecee67a00f5f 100644 --- 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 -- 2.0.1 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
