• Peter Zijlstra's avatar
    locking/mutex: Disable optimistic spinning on some architectures · e6be7d31
    Peter Zijlstra authored
    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: 's avatarPeter Zijlstra <peterz@infradead.org>
    Reported-by: 's avatarMikulas 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.netSigned-off-by: 's avatarIngo Molnar <mingo@kernel.org>
    Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    e6be7d31
Kconfig.locks 4.32 KB