> The high level overview is that it is stored in a shared page, mapped > into each new process's memory space at start-up. The kernel is never > entered; there are no context switches. The kernel has a timer that > updates this page atomically.
i wonder if that is uniformly faster. consider that making reads of that page coherent enough on a big multiprocessor and making sure there's not too much interprocesser skew might be slower than a system call. - erik
