Mapped File Page Boundary Improvements
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
By using the read protection mechanism to trigger the fault handler on a write operation for a mapped file, initializing of partial or complete blocks with zeros is avoided when a write extension is made to the file. This results in improved performance, reduced I/O overhead, and synchronization of the real memory area to the UNIX* directory structure. When a write extension is made to a mapped file in a Virtual Memory Manager (VMM) environment, it is desirable to avoid initializing partial blocks or complete blocks to zero with a read I/O operation. By using a "Write New" function, the initializing to zeros is avoided, which results in a reduced disk I/O overhead, improved kernel performance and maintained synchronization of the real memory area to the UNIX directory structure.