3.2.62-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <pet...@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 <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> [bwh: Backported to 3.2: - Adjust context - Drop arm64 change] Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- --- 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 --- 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 --- 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 --- 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) --- 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 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
