[PATCH v2 15/20] arm64: cmpxchg: avoid memory barrier on comparison failure

[Catalin Marinas]

On Fri, Jul 24, 2015 at 11:42:06AM +0100, Will Deacon wrote:
> cmpxchg doesn't require memory barrier semantics when the value
> comparison fails, so make the barrier conditional on success.
> 
> Reviewed-by: Steve Capper <steve.capper at arm.com>
> Signed-off-by: Will Deacon <will.deacon at arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>