+ help
+ Old PentiumPro multiprocessor systems had errata that could cause memory
+ operations to violate the x86 ordering standard in rare cases. Enabling this
+ option will attempt to work around some (but not all) occurances of
+ this problem, at the cost of much heavier spinlock and memory barrier
+ operations.
+
+ If unsure, say n here. Even distro kernels should think twice before enabling
+ this: there are few systems, and an unlikely bug.