From 4badad352a6bb202ec68afa7a574c0bb961e5ebc Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 6 Jun 2014 19:53:16 +0200 Subject: locking/mutex: Disable optimistic spinning on some architectures 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 Reported-by: Mikulas Patocka Cc: David Miller Cc: Chris Metcalf Cc: James Bottomley Cc: Vineet Gupta Cc: Jason Low Cc: Waiman Long Cc: "James E.J. Bottomley" Cc: Paul McKenney Cc: John David Anglin Cc: James Hogan Cc: Linus Torvalds Cc: Davidlohr Bueso Cc: stable@vger.kernel.org Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Russell King Cc: Will Deacon 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 --- kernel/Kconfig.locks | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 35536d9c0964..81907941d921 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -220,9 +220,12 @@ 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 config ARCH_USE_QUEUE_RWLOCK bool -- cgit v1.2.3