Full duplex solaris?

Most textbook replacement algorithms simply return target page as their result. This means that if target page is dirty (that is, contains data that have to be written to the stable storage before page can be reclaimed), I/O has to be initiated to send that page to the stable storage (to clean the page). In the early days of virtual memory, time wasted on cleaning wasn't of much concerns, because virtual memory was first implemented on systems with full duplex channels to the stable storage, and cleaning was customarily overlapped with pagein. Contemporary commodity hardware, on the other hand, doesn't support full duplex transfers, and cleaning of target pages becomes an issue.