Hi Stephen, Benjamin forwarded me your email stating: > I have been playing with userspace-rcu which has a number of neat > lockless routines for queuing and hashing. But there aren't kernel versions > and several of them may require cmpxchg to work. Just FYI, I made sure a few years ago that cmpxchg is implemented on all architectures within the Linux kernel (using a interrupt disable fallback on the cases where it is not supported architecturally, on UP-only architectures), so we should be good to use the lock-free structures as-is in the kernel on this front. As for the RCU use by these structures, userspace RCU has very much the same semantic as in the kernel, so we can implement and test these structures in userspace and eventually port them to the kernel as needed. Lai Jiangshan is actively working at making sure the user-level implementation of the RCU lock-free hash table (currently in a development branch of the userspace RCU git tree : urcu/ht-shrink, not yet in master) is suitable for use in the Linux kernel too. Best regards, Mathieu -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
