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authorPeter Zijlstra <peterz@infradead.org>2014-06-06 19:53:16 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-28 08:06:03 -0700
commit2e3ca7f6ea58cda872675259cdf9a566992bb6cf (patch)
tree4e9474bc1e492d7a6b978eac0dfcbac05f52fce1 /arch/powerpc
parent9abefe6933601246129da98d6c16936547a5cc8e (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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2156fa2d25fe..ee3c6608126a 100644
--- 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